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KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (2)

Status: closed as invalid on 2019/11/19 14:04
Subsystems: ext4
[Documentation on labels]
First crash: 1647d, last: 1619d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __ext4_new_inode / find_next_zero_bit ext4 4 1654d 1664d 0/26 closed as invalid on 2019/10/15 15:50
upstream KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (3) ext4 106 1532d 1570d 0/26 auto-closed as invalid on 2020/04/23 13:26
upstream KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (4) ext4 1337 1084d 1398d 0/26 auto-closed as invalid on 2021/06/04 08:21

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __ext4_new_inode / find_next_zero_bit

write to 0xffff88811c7aa040 of 8 bytes by task 11260 on cpu 1:
 __test_and_set_bit include/asm-generic/bitops-instrumented.h:168 [inline]
 __test_and_set_bit_le include/asm-generic/bitops/le.h:90 [inline]
 __ext4_new_inode+0xf04/0x2ec0 fs/ext4/ialloc.c:944
 ext4_symlink+0x30e/0x970 fs/ext4/namei.c:3262
 vfs_symlink fs/namei.c:4119 [inline]
 vfs_symlink+0x218/0x310 fs/namei.c:4105
 do_symlinkat+0x1a5/0x1e0 fs/namei.c:4146
 __do_sys_symlink fs/namei.c:4165 [inline]
 __se_sys_symlink fs/namei.c:4163 [inline]
 __x64_sys_symlink+0x3f/0x50 fs/namei.c:4163
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811c7aa040 of 8 bytes by task 11261 on cpu 0:
 _find_next_bit lib/find_bit.c:39 [inline]
 find_next_zero_bit+0x4e/0xe0 lib/find_bit.c:79
 find_next_zero_bit_le include/asm-generic/bitops/le.h:15 [inline]
 find_inode_bit.isra.0+0x82/0x300 fs/ext4/ialloc.c:715
 __ext4_new_inode+0xd10/0x2ec0 fs/ext4/ialloc.c:914
 ext4_symlink+0x30e/0x970 fs/ext4/namei.c:3262
 vfs_symlink fs/namei.c:4119 [inline]
 vfs_symlink+0x218/0x310 fs/namei.c:4105
 do_symlinkat+0x1a5/0x1e0 fs/namei.c:4146
 __do_sys_symlink fs/namei.c:4165 [inline]
 __se_sys_symlink fs/namei.c:4163 [inline]
 __x64_sys_symlink+0x3f/0x50 fs/namei.c:4163
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11261 Comm: syz-executor.5 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/11/19 08:58 https://github.com/google/ktsan.git kcsan 5863cc791e4c 432c7650 .config console log report ci2-upstream-kcsan-gce
2019/11/17 08:44 https://github.com/google/ktsan.git kcsan 5863cc791e4c d5696d51 .config console log report ci2-upstream-kcsan-gce
2019/11/16 05:52 https://github.com/google/ktsan.git kcsan 5863cc791e4c cdac920b .config console log report ci2-upstream-kcsan-gce
2019/11/15 14:02 https://github.com/google/ktsan.git kcsan 5863cc791e4c 79248ee8 .config console log report ci2-upstream-kcsan-gce
2019/11/12 08:47 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/11/11 16:30 https://github.com/google/ktsan.git kcsan 94c006602e13 377d77fa .config console log report ci2-upstream-kcsan-gce
2019/11/09 22:46 https://github.com/google/ktsan.git kcsan 94c006602e13 dc438b91 .config console log report ci2-upstream-kcsan-gce
2019/11/08 07:15 https://github.com/google/ktsan.git kcsan 94c006602e13 1e35461e .config console log report ci2-upstream-kcsan-gce
2019/11/07 16:09 https://github.com/google/ktsan.git kcsan 94c006602e13 f39aff9e .config console log report ci2-upstream-kcsan-gce
2019/11/07 03:25 https://github.com/google/ktsan.git kcsan 94c006602e13 d797d201 .config console log report ci2-upstream-kcsan-gce
2019/11/06 15:18 https://github.com/google/ktsan.git kcsan 94c006602e13 da505f84 .config console log report ci2-upstream-kcsan-gce
2019/11/06 03:06 https://github.com/google/ktsan.git kcsan 94c006602e13 bc2c6e45 .config console log report ci2-upstream-kcsan-gce
2019/11/05 14:59 https://github.com/google/ktsan.git kcsan 94c006602e13 af5c522d .config console log report ci2-upstream-kcsan-gce
2019/11/05 12:09 https://github.com/google/ktsan.git kcsan 94c006602e13 0f3ec414 .config console log report ci2-upstream-kcsan-gce
2019/11/05 00:09 https://github.com/google/ktsan.git kcsan 94c006602e13 76630fc9 .config console log report ci2-upstream-kcsan-gce
2019/11/04 15:30 https://github.com/google/ktsan.git kcsan 94c006602e13 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/11/04 12:15 https://github.com/google/ktsan.git kcsan 05f2236801fe 18e12644 .config console log report ci2-upstream-kcsan-gce
2019/11/03 21:52 https://github.com/google/ktsan.git kcsan 05f2236801fe b35fad31 .config console log report ci2-upstream-kcsan-gce
2019/11/03 21:52 https://github.com/google/ktsan.git kcsan 05f2236801fe b35fad31 .config console log report ci2-upstream-kcsan-gce
2019/11/03 09:32 https://github.com/google/ktsan.git kcsan 05f2236801fe c9610487 .config console log report ci2-upstream-kcsan-gce
2019/11/02 21:24 https://github.com/google/ktsan.git kcsan 05f2236801fe d603afc9 .config console log report ci2-upstream-kcsan-gce
2019/11/01 18:59 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/11/01 18:51 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/11/01 18:48 https://github.com/google/ktsan.git kcsan 05f2236801fe 997ccc67 .config console log report ci2-upstream-kcsan-gce
2019/10/30 21:13 https://github.com/google/ktsan.git kcsan 05f2236801fe a41ca8fa .config console log report ci2-upstream-kcsan-gce
2019/10/30 20:57 https://github.com/google/ktsan.git kcsan 05f2236801fe a41ca8fa .config console log report ci2-upstream-kcsan-gce
2019/10/29 04:19 https://github.com/google/ktsan.git kcsan 05f2236801fe 5ea87a66 .config console log report ci2-upstream-kcsan-gce
2019/10/28 16:27 https://github.com/google/ktsan.git kcsan 05f2236801fe 439d7b14 .config console log report ci2-upstream-kcsan-gce
2019/10/28 16:24 https://github.com/google/ktsan.git kcsan 05f2236801fe 439d7b14 .config console log report ci2-upstream-kcsan-gce
2019/10/26 11:44 https://github.com/google/ktsan.git kcsan 05f2236801fe 25bb509e .config console log report ci2-upstream-kcsan-gce
2019/10/25 23:51 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config console log report ci2-upstream-kcsan-gce
2019/10/25 11:47 https://github.com/google/ktsan.git kcsan 05f2236801fe 04ca72cd .config console log report ci2-upstream-kcsan-gce
2019/10/24 07:53 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
2019/10/23 14:47 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
2019/10/23 14:46 https://github.com/google/ktsan.git kcsan 05f2236801fe b602d64b .config console log report ci2-upstream-kcsan-gce
2019/10/23 02:34 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
2019/10/21 12:41 https://github.com/google/ktsan.git kcsan 05f2236801fe b24d2b8a .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.