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* Fix 'acccess_ok()' on alpha and SHLinus Torvalds2019-01-061-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'") broke both alpha and SH booting in qemu, as noticed by Guenter Roeck. It turns out that the bug wasn't actually in that commit itself (which would have been surprising: it was mostly a no-op), but in how the addition of access_ok() to the strncpy_from_user() and strnlen_user() functions now triggered the case where those functions would test the access of the very last byte of the user address space. The string functions actually did that user range test before too, but they did it manually by just comparing against user_addr_max(). But with user_access_begin() doing the check (using "access_ok()"), it now exposed problems in the architecture implementations of that function. For example, on alpha, the access_ok() helper macro looked like this: #define __access_ok(addr, size) \ ((get_fs().seg & (addr | size | (addr+size))) == 0) and what it basically tests is of any of the high bits get set (the USER_DS masking value is 0xfffffc0000000000). And that's completely wrong for the "addr+size" check. Because it's off-by-one for the case where we check to the very end of the user address space, which is exactly what the strn*_user() functions do. Why? Because "addr+size" will be exactly the size of the address space, so trying to access the last byte of the user address space will fail the __access_ok() check, even though it shouldn't. As a result, the user string accessor functions failed consistently - because they literally don't know how long the string is going to be, and the max access is going to be that last byte of the user address space. Side note: that alpha macro is buggy for another reason too - it re-uses the arguments twice. And SH has another version of almost the exact same bug: #define __addr_ok(addr) \ ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg) so far so good: yes, a user address must be below the limit. But then: #define __access_ok(addr, size) \ (__addr_ok((addr) + (size))) is wrong with the exact same off-by-one case: the case when "addr+size" is exactly _equal_ to the limit is actually perfectly fine (think "one byte access at the last address of the user address space") The SH version is actually seriously buggy in another way: it doesn't actually check for overflow, even though it did copy the _comment_ that talks about overflow. So it turns out that both SH and alpha actually have completely buggy implementations of access_ok(), but they happened to work in practice (although the SH overflow one is a serious serious security bug, not that anybody likely cares about SH security). This fixes the problems by using a similar macro on both alpha and SH. It isn't trying to be clever, the end address is based on this logic: unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; which basically says "add start and length, and then subtract one unless the length was zero". We can't subtract one for a zero length, or we'd just hit an underflow instead. For a lot of access_ok() users the length is a constant, so this isn't actually as expensive as it initially looks. Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-041-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kill strlen_user()Al Viro2017-05-161-1/+0
| | | | | | no callers, no consistent semantics, no sane way to use it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sh: switch to RAW_COPY_USERAl Viro2017-03-291-32/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sh: switch to extable.hAl Viro2017-03-291-22/+1
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* uaccess: drop duplicate includes from asm/uaccess.hAl Viro2017-03-061-2/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* uaccess: move VERIFY_{READ,WRITE} definitions to linux/uaccess.hAl Viro2017-03-061-3/+0
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sh: migrate exception table users off module.h and onto extable.hPaul Gortmaker2017-01-241-1/+0
| | | | | | | | | | | | | | | | | | | These files were only including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and avoid all the extra header content in module.h that we don't really need to compile these files. One uses "print_modules" so that prevents us removing module.h in that case, however. We also delete a duplicate prototype that doesn't need to exist, as it duplicates content in extable.h Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: linux-sh@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* exceptions: detritus removalAl Viro2016-09-281-2/+0
| | | | | | externs and defines for stuff that is never used Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sh: fix copy_from_user()Al Viro2016-09-131-1/+4
| | | | | Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* sh/uaccess: fix sparse errorsMichael S. Tsirkin2015-01-131-2/+2
| | | | | | | | | | virtio wants to read bitwise types from userspace using get_user. At the moment this triggers sparse errors, since the value is passed through an integer. Fix that up using __force. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel ↵David Howells2012-10-021-2/+2
| | | | | | | | | | | | system headers Convert #include "..." to #include <path/...> in kernel system headers. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
* sh: use the new generic strnlen_user() functionPaul Mundt2012-06-131-37/+3
| | | | | | | This discards both the _32 and _64 versions in favour of the consolidated generic one. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* sh: switch to generic strncpy_from_user().Paul Mundt2012-06-131-31/+4
| | | | | | | | This kills off the special sh32/64 versions and adopts the generic version. It should be possible to optimize this for SH-4A unaligned loads, but this is a corner case that can be supported incrementally. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* Disintegrate asm/system.h for SHDavid Howells2012-03-281-0/+14
| | | | | | | Disintegrate asm/system.h for SH. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-sh@vger.kernel.org
* sh: Proper __put_user_asm() size mismatch fix.OGAWA Hirofumi2008-07-291-2/+4
| | | | | | | | This fixes up the workaround in 2b4b2bb42137c779ef0084de5df66ff21b4cd86e and cleans up __put_user_asm() to get the sizing right from the onset. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* sh: migrate to arch/sh/include/Paul Mundt2008-07-291-0/+256
This follows the sparc changes a439fe51a1f8eb087c22dd24d69cebae4a3addac. Most of the moving about was done with Sam's directions at: http://marc.info/?l=linux-sh&m=121724823706062&w=2 with subsequent hacking and fixups entirely my fault. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Paul Mundt <lethal@linux-sh.org>