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* lkdtm: cfi: Make PAC test work with GCC 7 and 8Kristina Martsenko2022-12-151-1/+5
| | | | | | | | | | | | | | | The CFI test uses the branch-protection=none compiler attribute to disable PAC return address protection on a function. While newer GCC versions support this attribute, older versions (GCC 7 and 8) instead supported the sign-return-address=none attribute, leading to a build failure when the test is built with older compilers. Fix it by checking which attribute is supported and using the correct one. Fixes: 2e53b877dc12 ("lkdtm: Add CFI_BACKWARD to test ROP mitigations") Reported-by: Daniel Díaz <daniel.diaz@linaro.org> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/CAEUSe78kDPxQmQqCWW-_9LCgJDFhAeMoVBFnX9QLx18Z4uT4VQ@mail.gmail.com/
* docs: Fix path paste-o for /sys/kernel/warn_countKees Cook2022-12-141-1/+1
| | | | | | | | | | | | | | | | | Running "make htmldocs" shows that "/sys/kernel/oops_count" was duplicated. This should have been "warn_count": Warning: /sys/kernel/oops_count is defined 2 times: ./Documentation/ABI/testing/sysfs-kernel-warn_count:0 ./Documentation/ABI/testing/sysfs-kernel-oops_count:0 Fix the typo. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/linux-doc/202212110529.A3Qav8aR-lkp@intel.com Fixes: 8b05aa263361 ("panic: Expose "warn_count" to sysfs") Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* LoadPin: Ignore the "contents" argument of the LSM hooksKees Cook2022-12-141-12/+18
| | | | | | | | | | | | | | | | | LoadPin only enforces the read-only origin of kernel file reads. Whether or not it was a partial read isn't important. Remove the overly conservative checks so that things like partial firmware reads will succeed (i.e. reading a firmware header). Fixes: 2039bda1fa8d ("LSM: Add "contents" flag to kernel_read_file hook") Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge@hallyn.com> Tested-by: Ping-Ke Shih <pkshih@realtek.com> Link: https://lore.kernel.org/r/20221209195453.never.494-kees@kernel.org
* ksmbd: replace one-element arrays with flexible-array membersGustavo A. R. Silva2022-12-023-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | One-element arrays are deprecated, and we are replacing them with flexible array members instead. So, replace one-element arrays with flexible-array members in multiple structs in fs/ksmbd/smb_common.h and one in fs/ksmbd/smb2pdu.h. Important to mention is that doing a build before/after this patch results in no binary output differences. This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/242 Link: https://github.com/KSPP/linux/issues/79 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/Y3OxronfaPYv9qGP@work
* hpet: Replace one-element array with flexible-array memberKees Cook2022-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | One-element arrays are deprecated[1] and are being replaced with flexible array members in support of the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3. Replace one-element array with flexible-array member in struct hpet. This results in no differences in binary output. The use of struct hpet is never used with sizeof() and accesses via hpet_timers array are already done after explicit bounds checking. [1] https://github.com/KSPP/linux/issues/79 Cc: Clemens Ladisch <clemens@ladisch.de> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20221118034250.never.999-kees@kernel.org
* um: virt-pci: Avoid GCC non-NULL warningKees Cook2022-12-021-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GCC gets confused about the return value of get_cpu_var() possibly being NULL, so explicitly test for it before calls to memcpy() and memset(). Avoids warnings like this: arch/um/drivers/virt-pci.c: In function 'um_pci_send_cmd': include/linux/fortify-string.h:48:33: warning: argument 1 null where non-null expected [-Wnonnull] 48 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:438:9: note: in expansion of macro '__underlying_memcpy' 438 | __underlying_##op(p, q, __fortify_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:483:26: note: in expansion of macro '__fortify_memcpy_chk' 483 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ arch/um/drivers/virt-pci.c:100:9: note: in expansion of macro 'memcpy' 100 | memcpy(buf, cmd, cmd_size); | ^~~~~~ While at it, avoid literal "8" and use stored sizeof(buf->data) in memset() and um_pci_send_cmd(). Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202211271212.SUZSC9f9-lkp@intel.com Fixes: ba38961a069b ("um: Enable FORTIFY_SOURCE") Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Vincent Whitchurch <vincent.whitchurch@axis.com> Cc: linux-um@lists.infradead.org Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* signal: Initialize the info in ksignalhaifeng.xu2022-12-021-0/+1
| | | | | | | | | | | | When handing the SIGNAL_GROUP_EXIT flag, the info in ksignal isn't cleared. However, the info acquired by dequeue_synchronous_signal/dequeue_signal is initialized and can be safely used. Fortunately, the fatal signal process just uses the si_signo and doesn't use any other member. Even so, the initialization before use is more safer. Signed-off-by: haifeng.xu <haifeng.xu@shopee.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221128065606.19570-1-haifeng.xu@shopee.com
* lib: fortify_kunit: build without structleak pluginAnders Roxell2022-12-021-0/+1
| | | | | | | | | | | | | | Building allmodconfig with aarch64-linux-gnu-gcc (Debian 11.3.0-6), fortify_kunit with strucleak plugin enabled makes the stack frame size to grow too large: lib/fortify_kunit.c:140:1: error: the frame size of 2368 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Turn off the structleak plugin checks for fortify_kunit. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* panic: Expose "warn_count" to sysfsKees Cook2022-12-023-2/+27
| | | | | | | | | | | | | | | Since Warn count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/warn_count to expose it to userspace. Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org
* panic: Introduce warn_limitKees Cook2022-12-022-0/+24
| | | | | | | | | | | | | | | | | | | | | Like oops_limit, add warn_limit for limiting the number of warnings when panic_on_warn is not set. Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Petr Mladek <pmladek@suse.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-doc@vger.kernel.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org
* panic: Consolidate open-coded panic_on_warn checksKees Cook2022-12-027-12/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll their own warnings, and each check "panic_on_warn". Consolidate this into a single function so that future instrumentation can be added in a single location. Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Gow <davidgow@google.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: Jann Horn <jannh@google.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
* exit: Allow oops_limit to be disabledKees Cook2022-12-022-3/+4
| | | | | | | | | | | | | | | | | In preparation for keeping oops_limit logic in sync with warn_limit, have oops_limit == 0 disable checking the Oops counter. Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Jason A. Donenfeld" <Jason@zx2c4.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-doc@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* exit: Expose "oops_count" to sysfsKees Cook2022-12-013-2/+27
| | | | | | | | | | | | Since Oops count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/oops_count to expose it to userspace. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jann Horn <jannh@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
* exit: Put an upper limit on how often we can oopsJann Horn2022-12-012-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many Linux systems are configured to not panic on oops; but allowing an attacker to oops the system **really** often can make even bugs that look completely unexploitable exploitable (like NULL dereferences and such) if each crash elevates a refcount by one or a lock is taken in read mode, and this causes a counter to eventually overflow. The most interesting counters for this are 32 bits wide (like open-coded refcounts that don't use refcount_t). (The ldsem reader count on 32-bit platforms is just 16 bits, but probably nobody cares about 32-bit platforms that much nowadays.) So let's panic the system if the kernel is constantly oopsing. The speed of oopsing 2^32 times probably depends on several factors, like how long the stack trace is and which unwinder you're using; an empirically important one is whether your console is showing a graphical environment or a text console that oopses will be printed to. In a quick single-threaded benchmark, it looks like oopsing in a vfork() child with a very short stack trace only takes ~510 microseconds per run when a graphical console is active; but switching to a text console that oopses are printed to slows it down around 87x, to ~45 milliseconds per run. (Adding more threads makes this faster, but the actual oops printing happens under &die_lock on x86, so you can maybe speed this up by a factor of around 2 and then any further improvement gets eaten up by lock contention.) It looks like it would take around 8-12 days to overflow a 32-bit counter with repeated oopsing on a multi-core X86 system running a graphical environment; both me (in an X86 VM) and Seth (with a distro kernel on normal hardware in a standard configuration) got numbers in that ballpark. 12 days aren't *that* short on a desktop system, and you'd likely need much longer on a typical server system (assuming that people don't run graphical desktop environments on their servers), and this is a *very* noisy and violent approach to exploiting the kernel; and it also seems to take orders of magnitude longer on some machines, probably because stuff like EFI pstore will slow it down a ton if that's active. Signed-off-by: Jann Horn <jannh@google.com> Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org
* panic: Separate sysctl logic from CONFIG_SMPKees Cook2022-12-011-1/+3
| | | | | | | | | | | | | | | In preparation for adding more sysctls directly in kernel/panic.c, split CONFIG_SMP from the logic that adds sysctls. Cc: Petr Mladek <pmladek@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: tangmeng <tangmeng@uniontech.com> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221117234328.594699-1-keescook@chromium.org
* mm/pgtable: Fix multiple -Wstringop-overflow warningsGustavo A. R. Silva2022-12-011-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The actual size of the following arrays at run-time depends on CONFIG_X86_PAE. 427 pmd_t *u_pmds[MAX_PREALLOCATED_USER_PMDS]; 428 pmd_t *pmds[MAX_PREALLOCATED_PMDS]; If CONFIG_X86_PAE is not enabled, their final size will be zero (which is technically not a legal storage size in C, but remains "valid" via the GNU extension). In that case, the compiler complains about trying to access objects of size zero when calling functions where these objects are passed as arguments. Fix this by sanity-checking the size of those arrays just before the function calls. Also, the following warnings are fixed by these changes when building with GCC 11+ and -Wstringop-overflow enabled: arch/x86/mm/pgtable.c:437:13: warning: ‘preallocate_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] arch/x86/mm/pgtable.c:440:13: warning: ‘preallocate_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] arch/x86/mm/pgtable.c:462:9: warning: ‘free_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] arch/x86/mm/pgtable.c:455:9: warning: ‘pgd_prepopulate_user_pmd’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] arch/x86/mm/pgtable.c:464:9: warning: ‘free_pmds.constprop’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] This is one of the last cases in the ongoing effort to globally enable -Wstringop-overflow. The alternative to this is to make the originally suggested change: make the pmds argument from an array pointer to a pointer pointer. That situation is considered "legal" for C in the sense that it does not have a way to reason about the storage. i.e.: -static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmds[]) +static void pgd_prepopulate_pmd(struct mm_struct *mm, pgd_t *pgd, pmd_t **pmds) With the above change, there's no difference in binary output, and the compiler warning is silenced. However, with this patch, the compiler can actually figure out that it isn't using the code at all, and it gets dropped: text data bss dec hex filename 8218 718 32 8968 2308 arch/x86/mm/pgtable.o.before 7765 694 32 8491 212b arch/x86/mm/pgtable.o.after So this case (fixing a warning and reducing image size) is a clear win. Additionally drops an old work-around for GCC in the same code. Link: https://github.com/KSPP/linux/issues/203 Link: https://github.com/KSPP/linux/issues/181 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/Yytb67xvrnctxnEe@work
* mm: Make ksize() a reporting-only functionKees Cook2022-12-012-22/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With all "silently resizing" callers of ksize() refactored, remove the logic in ksize() that would allow it to be used to effectively change the size of an allocation (bypassing __alloc_size hints, etc). Users wanting this feature need to either use kmalloc_size_roundup() before an allocation, or use krealloc() directly. For kfree_sensitive(), move the unpoisoning logic inline. Replace the some of the partially open-coded ksize() in __do_krealloc with ksize() now that it doesn't perform unpoisoning. Adjust the KUnit tests to match the new ksize() behavior. Execution tested with: $ ./tools/testing/kunit/kunit.py run \ --kconfig_add CONFIG_KASAN=y \ --kconfig_add CONFIG_KASAN_GENERIC=y \ --arch x86_64 kasan Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-mm@kvack.org Cc: kasan-dev@googlegroups.com Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Enhanced-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* kunit/fortify: Validate __alloc_size attribute resultsKees Cook2022-11-232-0/+256
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Validate the effect of the __alloc_size attribute on allocators. If the compiler doesn't support __builtin_dynamic_object_size(), skip the associated tests. (For GCC, just remove the "--make_options" line below...) $ ./tools/testing/kunit/kunit.py run --arch x86_64 \ --kconfig_add CONFIG_FORTIFY_SOURCE=y \ --make_options LLVM=1 fortify ... [15:16:30] ================== fortify (10 subtests) =================== [15:16:30] [PASSED] known_sizes_test [15:16:30] [PASSED] control_flow_split_test [15:16:30] [PASSED] alloc_size_kmalloc_const_test [15:16:30] [PASSED] alloc_size_kmalloc_dynamic_test [15:16:30] [PASSED] alloc_size_vmalloc_const_test [15:16:30] [PASSED] alloc_size_vmalloc_dynamic_test [15:16:30] [PASSED] alloc_size_kvmalloc_const_test [15:16:30] [PASSED] alloc_size_kvmalloc_dynamic_test [15:16:30] [PASSED] alloc_size_devm_kmalloc_const_test [15:16:30] [PASSED] alloc_size_devm_kmalloc_dynamic_test [15:16:30] ===================== [PASSED] fortify ===================== [15:16:30] ============================================================ [15:16:30] Testing complete. Ran 10 tests: passed: 10 [15:16:31] Elapsed time: 8.348s total, 0.002s configuring, 6.923s building, 1.075s running For earlier GCC prior to version 12, the dynamic tests will be skipped: [15:18:59] ================== fortify (10 subtests) =================== [15:18:59] [PASSED] known_sizes_test [15:18:59] [PASSED] control_flow_split_test [15:18:59] [PASSED] alloc_size_kmalloc_const_test [15:18:59] [SKIPPED] alloc_size_kmalloc_dynamic_test [15:18:59] [PASSED] alloc_size_vmalloc_const_test [15:18:59] [SKIPPED] alloc_size_vmalloc_dynamic_test [15:18:59] [PASSED] alloc_size_kvmalloc_const_test [15:18:59] [SKIPPED] alloc_size_kvmalloc_dynamic_test [15:18:59] [PASSED] alloc_size_devm_kmalloc_const_test [15:18:59] [SKIPPED] alloc_size_devm_kmalloc_dynamic_test [15:18:59] ===================== [PASSED] fortify ===================== [15:18:59] ============================================================ [15:18:59] Testing complete. Ran 10 tests: passed: 6, skipped: 4 [15:18:59] Elapsed time: 11.965s total, 0.002s configuring, 10.540s building, 1.068s running Cc: David Gow <davidgow@google.com> Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid()Nathan Chancellor2022-11-183-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/gpu/drm/sti/sti_hda.c:637:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] .mode_valid = sti_hda_connector_mode_valid, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/sti/sti_dvo.c:376:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] .mode_valid = sti_dvo_connector_mode_valid, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/sti/sti_hdmi.c:1035:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] .mode_valid = sti_hdmi_connector_mode_valid, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ->mode_valid() in 'struct drm_connector_helper_funcs' expects a return type of 'enum drm_mode_status', not 'int'. Adjust the return type of sti_{dvo,hda,hdmi}_connector_mode_valid() to match the prototype's to resolve the warning and CFI failure. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221102155623.3042869-1-nathan@kernel.org
* drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid()Nathan Chancellor2022-11-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed. A proposed warning in clang aims to catch these at compile time, which reveals: drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c:74:16: error: incompatible function pointer types initializing 'enum drm_mode_status (*)(struct drm_connector *, struct drm_display_mode *)' with an expression of type 'int (struct drm_connector *, struct drm_display_mode *)' [-Werror,-Wincompatible-function-pointer-types-strict] .mode_valid = fsl_dcu_drm_connector_mode_valid, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. ->mode_valid() in 'struct drm_connector_helper_funcs' expects a return type of 'enum drm_mode_status', not 'int'. Adjust the return type of fsl_dcu_drm_connector_mode_valid() to match the prototype's to resolve the warning and CFI failure. Link: https://github.com/ClangBuiltLinux/linux/issues/1750 Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221102154215.78059-1-nathan@kernel.org
* driver core: Add __alloc_size hint to devm allocatorsKees Cook2022-11-181-3/+4
| | | | | | | | | | | | | | | | | | Mark the devm_*alloc()-family of allocations with appropriate __alloc_size()/__realloc_size() hints so the compiler can attempt to reason about buffer lengths from allocations. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Nishanth Menon <nm@ti.com> Cc: Michael Kelley <mikelley@microsoft.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Won Chung <wonchung@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20221029074734.gonna.276-kees@kernel.org
* Merge branch 'for-linus/hardening' into for-next/hardeningKees Cook2022-11-081-1/+1
|\
| * vmlinux.lds.h: Fix placement of '.data..decrypted' sectionNathan Chancellor2022-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") fixed an orphan section warning by adding the '.data..decrypted' section to the linker script under the PERCPU_DECRYPTED_SECTION define but that placement introduced a panic with !SMP, as the percpu sections are not instantiated with that configuration so attempting to access variables defined with DEFINE_PER_CPU_DECRYPTED() will result in a page fault. Move the '.data..decrypted' section to the DATA_MAIN define so that the variables in it are properly instantiated at boot time with CONFIG_SMP=n. Cc: stable@vger.kernel.org Fixes: d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") Link: https://lore.kernel.org/cbbd3548-880c-d2ca-1b67-5bb93b291d5f@huawei.com/ Debugged-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: Zhao Wenhui <zhaowenhui8@huawei.com> Tested-by: xiafukun <xiafukun@huawei.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221108174934.3384275-1-nathan@kernel.org
* | overflow: Introduce overflows_type() and castable_to_type()Kees Cook2022-11-026-5/+431
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a robust overflows_type() macro to test if a variable or constant value would overflow another variable or type. This can be used as a constant expression for static_assert() (which requires a constant expression[1][2]) when used on constant values. This must be constructed manually, since __builtin_add_overflow() does not produce a constant expression[3]. Additionally adds castable_to_type(), similar to __same_type(), but for checking if a constant value would overflow if cast to a given type. Add unit tests for overflows_type(), __same_type(), and castable_to_type() to the existing KUnit "overflow" test: [16:03:33] ================== overflow (21 subtests) ================== ... [16:03:33] [PASSED] overflows_type_test [16:03:33] [PASSED] same_type_test [16:03:33] [PASSED] castable_to_type_test [16:03:33] ==================== [PASSED] overflow ===================== [16:03:33] ============================================================ [16:03:33] Testing complete. Ran 21 tests: passed: 21 [16:03:33] Elapsed time: 24.022s total, 0.002s configuring, 22.598s building, 0.767s running [1] https://en.cppreference.com/w/c/language/_Static_assert [2] C11 standard (ISO/IEC 9899:2011): 6.7.10 Static assertions [3] https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html 6.56 Built-in Functions to Perform Arithmetic with Overflow Checking Built-in Function: bool __builtin_add_overflow (type1 a, type2 b, Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Tom Rix <trix@redhat.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: Vitor Massaru Iha <vitor@massaru.org> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: linux-hardening@vger.kernel.org Cc: llvm@lists.linux.dev Co-developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221024201125.1416422-1-gwan-gyeong.mun@intel.com
* | coredump: Proactively round up to kmalloc bucket sizeKees Cook2022-11-011-2/+5
| | | | | | | | | | | | | | | | | | | | | | Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* | btrfs: send: Proactively round up to kmalloc bucket sizeKees Cook2022-11-011-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: linux-btrfs@vger.kernel.org Acked-by: David Sterba <dsterba@suse.com> Link: https://lore.kernel.org/lkml/20220922133014.GI32411@suse.cz Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220923202822.2667581-8-keescook@chromium.org
* | dma-buf: Proactively round up to kmalloc bucket sizeKees Cook2022-11-011-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221018090858.never.941-kees@kernel.org
* | kbuild: upgrade the orphan section warning to an error if CONFIG_WERROR is setXin Li2022-11-016-8/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrew Cooper suggested upgrading the orphan section warning to a hard link error. However Nathan Chancellor said outright turning the warning into an error with no escape hatch might be too aggressive, as we have had these warnings triggered by new compiler generated sections, and suggested turning orphan sections into an error only if CONFIG_WERROR is set. Kees Cook echoed and emphasized that the mandate from Linus is that we should avoid breaking builds. It wrecks bisection, it causes problems across compiler versions, etc. Thus upgrade the orphan section warning to a hard link error only if CONFIG_WERROR is set. Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Suggested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Xin Li <xin3.li@intel.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221025073023.16137-2-xin3.li@intel.com
* | cred: Do not default to init_cred in prepare_kernel_cred()Kees Cook2022-11-019-17/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A common exploit pattern for ROP attacks is to abuse prepare_kernel_cred() in order to construct escalated privileges[1]. Instead of providing a short-hand argument (NULL) to the "daemon" argument to indicate using init_cred as the base cred, require that "daemon" is always set to an actual task. Replace all existing callers that were passing NULL with &init_task. Future attacks will need to have sufficiently powerful read/write primitives to have found an appropriately privileged task and written it to the ROP stack as an argument to succeed, which is similarly difficult to the prior effort needed to escalate privileges before struct cred existed: locate the current cred and overwrite the uid member. This has the added benefit of meaning that prepare_kernel_cred() can no longer exceed the privileges of the init task, which may have changed from the original init_cred (e.g. dropping capabilities from the bounding set). [1] https://google.com/search?q=commit_creds(prepare_kernel_cred(0)) Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: David Howells <dhowells@redhat.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Steve French <sfrench@samba.org> Cc: Ronnie Sahlberg <lsahlber@redhat.com> Cc: Shyam Prasad N <sprasad@microsoft.com> Cc: Tom Talpey <tom@talpey.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: "Michal Koutný" <mkoutny@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Russ Weight <russell.h.weight@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Link: https://lore.kernel.org/r/20221026232943.never.775-kees@kernel.org
* | fortify: Do not cast to "unsigned char"Kees Cook2022-11-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Do not cast to "unsigned char", as this needlessly creates type problems when attempting builds without -Wno-pointer-sign[1]. The intent of the cast is to drop possible "const" types. [1] https://lore.kernel.org/lkml/CAHk-=wgz3Uba8w7kdXhsqR1qvfemYL+OFQdefJnkeqXG8qZ_pA@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: 3009f891bb9f ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths") Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* | siphash: Convert selftest to KUnitKees Cook2022-11-014-106/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the siphash self-test to KUnit so it will be included in "all KUnit tests" coverage, and can be run individually still: $ ./tools/testing/kunit/kunit.py run siphash ... [02:58:45] Starting KUnit Kernel (1/1)... [02:58:45] ============================================================ [02:58:45] =================== siphash (1 subtest) ==================== [02:58:45] [PASSED] siphash_test [02:58:45] ===================== [PASSED] siphash ===================== [02:58:45] ============================================================ [02:58:45] Testing complete. Ran 1 tests: passed: 1 [02:58:45] Elapsed time: 21.421s total, 4.306s configuring, 16.947s building, 0.148s running Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org> Cc: Yury Norov <yury.norov@gmail.com> Cc: Sander Vanheule <sander@svanheule.net> Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com> Link: https://lore.kernel.org/lkml/CAHmME9r+9MPH6zk3Vn=buEMSbQiWMFryqqzerKarmjYk+tHLJA@mail.gmail.com Tested-by: David Gow <davidgow@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* | fortify: Short-circuit known-safe calls to strscpy()Kees Cook2022-11-012-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replacing compile-time safe calls of strcpy()-related functions with strscpy() was always calling the full strscpy() logic when a builtin would be better. For example: char buf[16]; strcpy(buf, "yes"); would reduce to __builtin_memcpy(buf, "yes", 4), but not if it was: strscpy(buf, yes, sizeof(buf)); Fix this by checking if all sizes are known at compile-time. Cc: linux-hardening@vger.kernel.org Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | string: Convert strscpy() self-test to KUnitKees Cook2022-11-015-154/+136
| | | | | | | | | | | | | | | | | | | | Convert the strscpy() self-test to a KUnit test. Cc: David Gow <davidgow@google.com> Cc: Tobin C. Harding <tobin@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/lkml/Y072ZMk/hNkfwqMv@dev-arch.thelio-3990X Signed-off-by: Kees Cook <keescook@chromium.org>
* | string: Add __realloc_size hint to kmemdup()Kees Cook2022-11-012-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add __realloc_size() hint to kmemdup() so the compiler can reason about the length of the returned buffer. (These must not use __alloc_size, since those include __malloc which says the contents aren't defined[1]). [1] https://lore.kernel.org/linux-hardening/d199c2af-06af-8a50-a6a1-00eefa0b67b4@prevas.dk/ Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Andy Shevchenko <andriy.shevchenko@intel.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | kunit/memcpy: Add dynamic size and window testsKees Cook2022-10-292-0/+206
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "side effects" memmove() test accidentally found[1] a corner case in the recent refactoring of the i386 assembly memmove(), but missed another corner case. Instead of hoping to get lucky next time, implement much more complete tests of memcpy() and memmove() -- especially the moving window overlap for memmove() -- which catches all the issues encountered and should catch anything new. [1] https://lore.kernel.org/lkml/CAKwvOdkaKTa2aiA90VzFrChNQM6O_ro+b7VWs=op70jx-DKaXA@mail.gmail.com Cc: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* | string: Rewrite and add more kern-doc for the str*() functionsKees Cook2022-10-294-93/+131
|/ | | | | | | | | | | | | | | | | While there were varying degrees of kern-doc for various str*()-family functions, many needed updating and clarification, or to just be entirely written. Update (and relocate) existing kern-doc and add missing functions, sadly shaking my head at how many times I have written "Do not use this function". Include the results in the core kernel API doc. Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Andy Shevchenko <andy@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-hardening@vger.kernel.org Tested-by: Akira Yokosawa <akiyks@gmail.com> Link: https://lore.kernel.org/lkml/9b0cf584-01b3-3013-b800-1ef59fe82476@gmail.com Signed-off-by: Kees Cook <keescook@chromium.org>
* fortify: Capture __bos() results in const temp varsKees Cook2022-10-291-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In two recent run-time memcpy() bound checking bug reports (NFS[1] and JFS[2]), the _detection_ was working correctly (in the sense that the requested copy size was larger than the destination field size), but the _warning text_ was showing the destination field size as SIZE_MAX ("unknown size"). This should be impossible, since the detection function will explicitly give up if the destination field size is unknown. For example, the JFS warning was: memcpy: detected field-spanning write (size 132) of single field "ip->i_link" at fs/jfs/namei.c:950 (size 18446744073709551615) Other cases of this warning (e.g.[3]) have reported correctly, and the reproducer only happens under GCC (at least 10.2 and 12.1), so this currently appears to be a GCC bug. Explicitly capturing the __builtin_object_size() results in const temporary variables fixes the report. For example, the JFS reproducer now correctly reports the field size (128): memcpy: detected field-spanning write (size 132) of single field "ip->i_link" at fs/jfs/namei.c:950 (size 128) Examination of the .text delta (which is otherwise identical), shows the literal value used in the report changing: - mov $0xffffffffffffffff,%rcx + mov $0x80,%ecx [1] https://lore.kernel.org/lkml/Y0zEzZwhOxTDcBTB@codemonkey.org.uk/ [2] https://syzkaller.appspot.com/bug?id=23d613df5259b977dac1696bec77f61a85890e3d [3] https://lore.kernel.org/all/202210110948.26b43120-yujie.liu@intel.com/ Cc: "Dr. David Alan Gilbert" <linux@treblig.org> Cc: llvm@lists.linux.dev Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* overflow: Refactor test skips for Clang-specific issuesKees Cook2022-10-251-17/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert test exclusion into test skipping. This brings the logic for why a test is being skipped into the test itself, instead of having to spread ifdefs around the code. This will make cleanup easier as minimum tests get raised. Drop __maybe_unused so missed tests will be noticed again and clean up whitespace. For example, clang-11 on i386: [15:52:32] ================== overflow (18 subtests) ================== [15:52:32] [PASSED] u8_u8__u8_overflow_test [15:52:32] [PASSED] s8_s8__s8_overflow_test [15:52:32] [PASSED] u16_u16__u16_overflow_test [15:52:32] [PASSED] s16_s16__s16_overflow_test [15:52:32] [PASSED] u32_u32__u32_overflow_test [15:52:32] [PASSED] s32_s32__s32_overflow_test [15:52:32] [SKIPPED] u64_u64__u64_overflow_test [15:52:32] [SKIPPED] s64_s64__s64_overflow_test [15:52:32] [SKIPPED] u32_u32__int_overflow_test [15:52:32] [PASSED] u32_u32__u8_overflow_test [15:52:32] [PASSED] u8_u8__int_overflow_test [15:52:32] [PASSED] int_int__u8_overflow_test [15:52:32] [PASSED] shift_sane_test [15:52:32] [PASSED] shift_overflow_test [15:52:32] [PASSED] shift_truncate_test [15:52:32] [PASSED] shift_nonsense_test [15:52:32] [PASSED] overflow_allocation_test [15:52:32] [PASSED] overflow_size_helpers_test [15:52:32] ==================== [PASSED] overflow ===================== [15:52:32] ============================================================ [15:52:32] Testing complete. Ran 18 tests: passed: 15, skipped: 3 Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Tom Rix <trix@redhat.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20221006230017.1833458-1-keescook@chromium.org
* overflow: disable failing tests for older clang versionsNick Desaulniers2022-10-251-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Building the overflow kunit tests with clang-11 fails with: $ ./tools/testing/kunit/kunit.py run --arch=arm --make_options LLVM=1 \ overflow ... ld.lld: error: undefined symbol: __mulodi4 ... Clang 11 and earlier generate unwanted libcalls for signed output, unsigned input. Disable these tests for now, but should these become used in the kernel we might consider that as justification for dropping clang-11 support. Keep the clang-11 build alive a little bit longer. Avoid -Wunused-function warnings via __maybe_unused. To test W=1: $ make LLVM=1 -j128 defconfig $ ./scripts/config -e KUNIT -e KUNIT_ALL $ make LLVM=1 -j128 olddefconfig lib/overflow_kunit.o W=1 Link: https://github.com/ClangBuiltLinux/linux/issues/1711 Link: https://github.com/llvm/llvm-project/commit/3203143f1356a4e4e3ada231156fc6da6e1a9f9d Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221006171751.3444575-1-ndesaulniers@google.com
* overflow: Fix kern-doc markup for functionsKees Cook2022-10-253-25/+22
| | | | | | | | | | | | Fix the kern-doc markings for several of the overflow helpers and move their location into the core kernel API documentation, where it belongs (it's not driver-specific). Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: linux-hardening@vger.kernel.org Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* Linux 6.1-rc1v6.1-rc1Linus Torvalds2022-10-171-2/+2
|
* Merge tag 'random-6.1-rc1-for-linus' of ↵Linus Torvalds2022-10-17185-421/+378
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1
| * prandom: remove unused functionsJason A. Donenfeld2022-10-123-23/+5
| | | | | | | | | | | | | | | | | | | | | | | | With no callers left of prandom_u32() and prandom_bytes(), as well as get_random_int(), remove these deprecated wrappers, in favor of get_random_u32() and get_random_bytes(). Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use get_random_bytes() when possibleJason A. Donenfeld2022-10-1219-24/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The prandom_bytes() function has been a deprecated inline wrapper around get_random_bytes() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> # powerpc Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use get_random_u32() when possibleJason A. Donenfeld2022-10-1271-100/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prandom_u32() function has been a deprecated inline wrapper around get_random_u32() for several releases now, and compiles down to the exact same code. Replace the deprecated wrapper with a direct call to the real function. The same also applies to get_random_int(), which is just a wrapper around get_random_u32(). This was done as a basic find and replace. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Acked-by: Chuck Lever <chuck.lever@oracle.com> # for nfsd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for thunderbolt Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Acked-by: Helge Deller <deller@gmx.de> # for parisc Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use get_random_{u8,u16}() when possible, part 2Jason A. Donenfeld2022-10-126-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, simply use the get_random_{u8,u16}() functions, which are faster than wasting the additional bytes from a 32-bit value. This was done by hand, identifying all of the places where one of the random integer functions was used in a non-32-bit context. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use get_random_{u8,u16}() when possible, part 1Jason A. Donenfeld2022-10-1221-34/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, simply use the get_random_{u8,u16}() functions, which are faster than wasting the additional bytes from a 32-bit value. This was done mechanically with this coccinelle script: @@ expression E; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; typedef __be16; typedef __le16; typedef u8; @@ ( - (get_random_u32() & 0xffff) + get_random_u16() | - (get_random_u32() & 0xff) + get_random_u8() | - (get_random_u32() % 65536) + get_random_u16() | - (get_random_u32() % 256) + get_random_u8() | - (get_random_u32() >> 16) + get_random_u16() | - (get_random_u32() >> 24) + get_random_u8() | - (u16)get_random_u32() + get_random_u16() | - (u8)get_random_u32() + get_random_u8() | - (__be16)get_random_u32() + (__be16)get_random_u16() | - (__le16)get_random_u32() + (__le16)get_random_u16() | - prandom_u32_max(65536) + get_random_u16() | - prandom_u32_max(256) + get_random_u8() | - E->inet_id = get_random_u32() + E->inet_id = get_random_u16() ) @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; identifier v; @@ - u16 v = get_random_u32(); + u16 v = get_random_u16(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u8; identifier v; @@ - u8 v = get_random_u32(); + u8 v = get_random_u8(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u16; u16 v; @@ - v = get_random_u32(); + v = get_random_u16(); @@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u8; u8 v; @@ - v = get_random_u32(); + v = get_random_u8(); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Examine limits @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value < 256: coccinelle.RESULT = cocci.make_ident("get_random_u8") elif value < 65536: coccinelle.RESULT = cocci.make_ident("get_random_u16") else: print("Skipping large mask of %s" % (literal)) cocci.include_match(False) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; identifier add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + (RESULT() & LITERAL) Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use prandom_u32_max() when possible, part 2Jason A. Donenfeld2022-10-124-19/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done by hand, covering things that coccinelle could not do on its own. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> # for ext2, ext4, and sbitmap Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
| * treewide: use prandom_u32_max() when possible, part 1Jason A. Donenfeld2022-10-1289-218/+204
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than incurring a division or requesting too many random bytes for the given range, use the prandom_u32_max() function, which only takes the minimum required bytes from the RNG and avoids divisions. This was done mechanically with this coccinelle script: @basic@ expression E; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; typedef u64; @@ ( - ((T)get_random_u32() % (E)) + prandom_u32_max(E) | - ((T)get_random_u32() & ((E) - 1)) + prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2) | - ((u64)(E) * get_random_u32() >> 32) + prandom_u32_max(E) | - ((T)get_random_u32() & ~PAGE_MASK) + prandom_u32_max(PAGE_SIZE) ) @multi_line@ identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; identifier RAND; expression E; @@ - RAND = get_random_u32(); ... when != RAND - RAND %= (E); + RAND = prandom_u32_max(E); // Find a potential literal @literal_mask@ expression LITERAL; type T; identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32"; position p; @@ ((T)get_random_u32()@p & (LITERAL)) // Add one to the literal. @script:python add_one@ literal << literal_mask.LITERAL; RESULT; @@ value = None if literal.startswith('0x'): value = int(literal, 16) elif literal[0] in '123456789': value = int(literal, 10) if value is None: print("I don't know how to handle %s" % (literal)) cocci.include_match(False) elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1: print("Skipping 0x%x for cleanup elsewhere" % (value)) cocci.include_match(False) elif value & (value + 1) != 0: print("Skipping 0x%x because it's not a power of two minus one" % (value)) cocci.include_match(False) elif literal.startswith('0x'): coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1)) else: coccinelle.RESULT = cocci.make_expr("%d" % (value + 1)) // Replace the literal mask with the calculated result. @plus_one@ expression literal_mask.LITERAL; position literal_mask.p; expression add_one.RESULT; identifier FUNC; @@ - (FUNC()@p & (LITERAL)) + prandom_u32_max(RESULT) @collapse_ret@ type T; identifier VAR; expression E; @@ { - T VAR; - VAR = (E); - return VAR; + return E; } @drop_var@ type T; identifier VAR; @@ { - T VAR; ... when != VAR } Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: KP Singh <kpsingh@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd Acked-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390 Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
* | Merge tag 'perf-tools-for-v6.1-2-2022-10-16' of ↵Linus Torvalds2022-10-1736-71/+1265
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull more perf tools updates from Arnaldo Carvalho de Melo: - Use BPF CO-RE (Compile Once, Run Everywhere) to support old kernels when using bperf (perf BPF based counters) with cgroups. - Support HiSilicon PCIe Performance Monitoring Unit (PMU), that monitors bandwidth, latency, bus utilization and buffer occupancy. Documented in Documentation/admin-guide/perf/hisi-pcie-pmu.rst. - User space tasks can migrate between CPUs, so when tracing selected CPUs, system-wide sideband is still needed, fix it in the setup of Intel PT on hybrid systems. - Fix metricgroups title message in 'perf list', it should state that the metrics groups are to be used with the '-M' option, not '-e'. - Sync the msr-index.h copy with the kernel sources, adding support for using "AMD64_TSC_RATIO" in filter expressions in 'perf trace' as well as decoding it when printing the MSR tracepoint arguments. - Fix program header size and alignment when generating a JIT ELF in 'perf inject'. - Add multiple new Intel PT 'perf test' entries, including a jitdump one. - Fix the 'perf test' entries for 'perf stat' CSV and JSON output when running on PowerPC due to an invalid topology number in that arch. - Fix the 'perf test' for arm_coresight failures on the ARM Juno system. - Fix the 'perf test' attr entry for PERF_FORMAT_LOST, adding this option to the or expression expected in the intercepted perf_event_open() syscall. - Add missing condition flags ('hs', 'lo', 'vc', 'vs') for arm64 in the 'perf annotate' asm parser. - Fix 'perf mem record -C' option processing, it was being chopped up when preparing the underlying 'perf record -e mem-events' and thus being ignored, requiring using '-- -C CPUs' as a workaround. - Improvements and tidy ups for 'perf test' shell infra. - Fix Intel PT information printing segfault in uClibc, where a NULL format was being passed to fprintf. * tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (23 commits) tools arch x86: Sync the msr-index.h copy with the kernel sources perf auxtrace arm64: Add support for parsing HiSilicon PCIe Trace packet perf auxtrace arm64: Add support for HiSilicon PCIe Tune and Trace device driver perf auxtrace arm: Refactor event list iteration in auxtrace_record__init() perf tests stat+json_output: Include sanity check for topology perf tests stat+csv_output: Include sanity check for topology perf intel-pt: Fix system_wide dummy event for hybrid perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc perf test: Fix attr tests for PERF_FORMAT_LOST perf test: test_intel_pt.sh: Add 9 tests perf inject: Fix GEN_ELF_TEXT_OFFSET for jit perf test: test_intel_pt.sh: Add jitdump test perf test: test_intel_pt.sh: Tidy some alignment perf test: test_intel_pt.sh: Print a message when skipping kernel tracing perf test: test_intel_pt.sh: Tidy some perf record options perf test: test_intel_pt.sh: Fix return checking again perf: Skip and warn on unknown format 'configN' attrs perf list: Fix metricgroups title message perf mem: Fix -C option behavior for perf mem record perf annotate: Add missing condition flags for arm64 ...
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-06 04:45:53 +0100