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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 21:55:35 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-08 21:55:35 +0200 |
commit | 2d338201d5311bcd79d42f66df4cecbcbc5f4f2c (patch) | |
tree | 75d87f65c31f4721ba6a5356d2a487af9e2961c3 /Documentation/dev-tools | |
parent | Merge tag 'mm-slub-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git... (diff) | |
parent | scripts: check_extable: fix typo in user error message (diff) | |
download | linux-2d338201d5311bcd79d42f66df4cecbcbc5f4f2c.tar.xz linux-2d338201d5311bcd79d42f66df4cecbcbc5f4f2c.zip |
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
"147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f.
Subsystems affected by this patch series: mm (memory-hotplug, rmap,
ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
selftests, ipc, and scripts"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
scripts: check_extable: fix typo in user error message
mm/workingset: correct kernel-doc notations
ipc: replace costly bailout check in sysvipc_find_ipc()
selftests/memfd: remove unused variable
Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
configs: remove the obsolete CONFIG_INPUT_POLLDEV
prctl: allow to setup brk for et_dyn executables
pid: cleanup the stale comment mentioning pidmap_init().
kernel/fork.c: unexport get_{mm,task}_exe_file
coredump: fix memleak in dump_vma_snapshot()
fs/coredump.c: log if a core dump is aborted due to changed file permissions
nilfs2: use refcount_dec_and_lock() to fix potential UAF
nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
nilfs2: fix NULL pointer in nilfs_##name##_attr_release
nilfs2: fix memory leak in nilfs_sysfs_create_device_group
trap: cleanup trap_init()
init: move usermodehelper_enable() to populate_rootfs()
...
Diffstat (limited to 'Documentation/dev-tools')
-rw-r--r-- | Documentation/dev-tools/kfence.rst | 98 |
1 files changed, 53 insertions, 45 deletions
diff --git a/Documentation/dev-tools/kfence.rst b/Documentation/dev-tools/kfence.rst index fdf04e741ea5..0fbe3308bf37 100644 --- a/Documentation/dev-tools/kfence.rst +++ b/Documentation/dev-tools/kfence.rst @@ -65,25 +65,27 @@ Error reports A typical out-of-bounds access looks like this:: ================================================================== - BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0xa3/0x22b + BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0xa6/0x234 - Out-of-bounds read at 0xffffffffb672efff (1B left of kfence-#17): - test_out_of_bounds_read+0xa3/0x22b - kunit_try_run_case+0x51/0x85 + Out-of-bounds read at 0xffff8c3f2e291fff (1B left of kfence-#72): + test_out_of_bounds_read+0xa6/0x234 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - kfence-#17 [0xffffffffb672f000-0xffffffffb672f01f, size=32, cache=kmalloc-32] allocated by task 507: - test_alloc+0xf3/0x25b - test_out_of_bounds_read+0x98/0x22b - kunit_try_run_case+0x51/0x85 + kfence-#72: 0xffff8c3f2e292000-0xffff8c3f2e29201f, size=32, cache=kmalloc-32 + + allocated by task 484 on cpu 0 at 32.919330s: + test_alloc+0xfe/0x738 + test_out_of_bounds_read+0x9b/0x234 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - CPU: 4 PID: 107 Comm: kunit_try_catch Not tainted 5.8.0-rc6+ #7 - Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 + CPU: 0 PID: 484 Comm: kunit_try_catch Not tainted 5.13.0-rc3+ #7 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 ================================================================== The header of the report provides a short summary of the function involved in @@ -96,30 +98,32 @@ Use-after-free accesses are reported as:: ================================================================== BUG: KFENCE: use-after-free read in test_use_after_free_read+0xb3/0x143 - Use-after-free read at 0xffffffffb673dfe0 (in kfence-#24): + Use-after-free read at 0xffff8c3f2e2a0000 (in kfence-#79): test_use_after_free_read+0xb3/0x143 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - kfence-#24 [0xffffffffb673dfe0-0xffffffffb673dfff, size=32, cache=kmalloc-32] allocated by task 507: - test_alloc+0xf3/0x25b + kfence-#79: 0xffff8c3f2e2a0000-0xffff8c3f2e2a001f, size=32, cache=kmalloc-32 + + allocated by task 488 on cpu 2 at 33.871326s: + test_alloc+0xfe/0x738 test_use_after_free_read+0x76/0x143 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - freed by task 507: + freed by task 488 on cpu 2 at 33.871358s: test_use_after_free_read+0xa8/0x143 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - CPU: 4 PID: 109 Comm: kunit_try_catch Tainted: G W 5.8.0-rc6+ #7 - Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 + CPU: 2 PID: 488 Comm: kunit_try_catch Tainted: G B 5.13.0-rc3+ #7 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 ================================================================== KFENCE also reports on invalid frees, such as double-frees:: @@ -127,30 +131,32 @@ KFENCE also reports on invalid frees, such as double-frees:: ================================================================== BUG: KFENCE: invalid free in test_double_free+0xdc/0x171 - Invalid free of 0xffffffffb6741000: + Invalid free of 0xffff8c3f2e2a4000 (in kfence-#81): test_double_free+0xdc/0x171 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - kfence-#26 [0xffffffffb6741000-0xffffffffb674101f, size=32, cache=kmalloc-32] allocated by task 507: - test_alloc+0xf3/0x25b + kfence-#81: 0xffff8c3f2e2a4000-0xffff8c3f2e2a401f, size=32, cache=kmalloc-32 + + allocated by task 490 on cpu 1 at 34.175321s: + test_alloc+0xfe/0x738 test_double_free+0x76/0x171 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - freed by task 507: + freed by task 490 on cpu 1 at 34.175348s: test_double_free+0xa8/0x171 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - CPU: 4 PID: 111 Comm: kunit_try_catch Tainted: G W 5.8.0-rc6+ #7 - Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 + CPU: 1 PID: 490 Comm: kunit_try_catch Tainted: G B 5.13.0-rc3+ #7 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 ================================================================== KFENCE also uses pattern-based redzones on the other side of an object's guard @@ -160,23 +166,25 @@ These are reported on frees:: ================================================================== BUG: KFENCE: memory corruption in test_kmalloc_aligned_oob_write+0xef/0x184 - Corrupted memory at 0xffffffffb6797ff9 [ 0xac . . . . . . ] (in kfence-#69): + Corrupted memory at 0xffff8c3f2e33aff9 [ 0xac . . . . . . ] (in kfence-#156): test_kmalloc_aligned_oob_write+0xef/0x184 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - kfence-#69 [0xffffffffb6797fb0-0xffffffffb6797ff8, size=73, cache=kmalloc-96] allocated by task 507: - test_alloc+0xf3/0x25b + kfence-#156: 0xffff8c3f2e33afb0-0xffff8c3f2e33aff8, size=73, cache=kmalloc-96 + + allocated by task 502 on cpu 7 at 42.159302s: + test_alloc+0xfe/0x738 test_kmalloc_aligned_oob_write+0x57/0x184 - kunit_try_run_case+0x51/0x85 + kunit_try_run_case+0x61/0xa0 kunit_generic_run_threadfn_adapter+0x16/0x30 - kthread+0x137/0x160 + kthread+0x176/0x1b0 ret_from_fork+0x22/0x30 - CPU: 4 PID: 120 Comm: kunit_try_catch Tainted: G W 5.8.0-rc6+ #7 - Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 + CPU: 7 PID: 502 Comm: kunit_try_catch Tainted: G B 5.13.0-rc3+ #7 + Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 ================================================================== For such errors, the address where the corruption occurred as well as the |