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KCSAN: data-race in ext4_free_inode / find_next_zero_bit (2)

Status: auto-closed as invalid on 2020/04/23 13:21
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+c092409cdb3bc5261b1f@syzkaller.appspotmail.com
First crash: 1640d, last: 1527d
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_free_inode / find_next_zero_bit ext4 7 1647d 1654d 0/26 closed as invalid on 2019/10/18 14:11
upstream KCSAN: data-race in ext4_free_inode / find_next_zero_bit (3) ext4 1164 1078d 1389d 0/26 auto-closed as invalid on 2021/06/04 08:24

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_free_inode / find_next_zero_bit

write to 0xffff88812055e018 of 8 bytes by task 7960 on cpu 1:
 instrument_write include/linux/instrumented.h:42 [inline]
 __test_and_clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:85 [inline]
 __test_and_clear_bit_le include/asm-generic/bitops/le.h:95 [inline]
 ext4_free_inode+0x5e5/0xa50 fs/ext4/ialloc.c:308
 ext4_evict_inode+0x87f/0xe50 fs/ext4/inode.c:316
 evict+0x244/0x410 fs/inode.c:574
 iput_final fs/inode.c:1563 [inline]
 iput+0x371/0x4e0 fs/inode.c:1589
 do_unlinkat+0x378/0x530 fs/namei.c:4073
 __do_sys_unlink fs/namei.c:4114 [inline]
 __se_sys_unlink fs/namei.c:4112 [inline]
 __x64_sys_unlink+0x3b/0x50 fs/namei.c:4112
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812055e018 of 8 bytes by task 16713 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:710
 __ext4_new_inode+0xd45/0x2f10 fs/ext4/ialloc.c:909
 ext4_symlink+0x31c/0x9b0 fs/ext4/namei.c:3275
 vfs_symlink fs/namei.c:4131 [inline]
 vfs_symlink+0x218/0x310 fs/namei.c:4117
 do_symlinkat+0x1a5/0x1e0 fs/namei.c:4158
 __do_sys_symlink fs/namei.c:4177 [inline]
 __se_sys_symlink fs/namei.c:4175 [inline]
 __x64_sys_symlink+0x3f/0x50 fs/namei.c:4175
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16713 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (136):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/13 12:52 https://github.com/google/ktsan.git kcsan f60f0f543333 e6247653 .config console log report ci2-upstream-kcsan-gce
2020/02/12 17:19 https://github.com/google/ktsan.git kcsan f60f0f543333 84f4fc8a .config console log report ci2-upstream-kcsan-gce
2020/02/12 05:37 https://github.com/google/ktsan.git kcsan f60f0f543333 a75b198c .config console log report ci2-upstream-kcsan-gce
2020/02/11 17:53 https://github.com/google/ktsan.git kcsan f60f0f543333 4d1ab643 .config console log report ci2-upstream-kcsan-gce
2020/02/11 07:43 https://github.com/google/ktsan.git kcsan f60f0f543333 084454ae .config console log report ci2-upstream-kcsan-gce
2020/02/10 19:03 https://github.com/google/ktsan.git kcsan f60f0f543333 d9e55b05 .config console log report ci2-upstream-kcsan-gce
2020/02/10 15:43 https://github.com/google/ktsan.git kcsan f60f0f543333 18847f55 .config console log report ci2-upstream-kcsan-gce
2020/02/09 21:52 https://github.com/google/ktsan.git kcsan f60f0f543333 35f5e45e .config console log report ci2-upstream-kcsan-gce
2020/02/09 10:49 https://github.com/google/ktsan.git kcsan f60f0f543333 6ece2ea5 .config console log report ci2-upstream-kcsan-gce
2020/02/08 10:44 https://github.com/google/ktsan.git kcsan f60f0f543333 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/07 15:26 https://github.com/google/ktsan.git kcsan 6cccb8ba35bd 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/07 00:28 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/06 11:56 https://github.com/google/ktsan.git kcsan 245a43005292 5be3a391 .config console log report ci2-upstream-kcsan-gce
2020/02/05 14:52 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/02/02 12:15 https://github.com/google/ktsan.git kcsan 245a43005292 93e5e335 .config console log report ci2-upstream-kcsan-gce
2020/02/01 23:25 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config console log report ci2-upstream-kcsan-gce
2020/02/01 10:30 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config console log report ci2-upstream-kcsan-gce
2020/01/31 19:45 https://github.com/google/ktsan.git kcsan 245a43005292 0eb59c27 .config console log report ci2-upstream-kcsan-gce
2020/01/29 15:39 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/28 17:22 https://github.com/google/ktsan.git kcsan 245a43005292 c8e81ce4 .config console log report ci2-upstream-kcsan-gce
2020/01/27 15:01 https://github.com/google/ktsan.git kcsan 245a43005292 56cd6c9b .config console log report ci2-upstream-kcsan-gce
2020/01/26 15:57 https://github.com/google/ktsan.git kcsan 245a43005292 dd56146d .config console log report ci2-upstream-kcsan-gce
2020/01/25 22:00 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config console log report ci2-upstream-kcsan-gce
2020/01/24 06:33 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/23 15:48 https://github.com/google/ktsan.git kcsan 245a43005292 11ebf937 .config console log report ci2-upstream-kcsan-gce
2020/01/22 18:37 https://github.com/google/ktsan.git kcsan 245a43005292 3334d684 .config console log report ci2-upstream-kcsan-gce
2020/01/20 22:04 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config console log report ci2-upstream-kcsan-gce
2020/01/20 10:42 https://github.com/google/ktsan.git kcsan 245a43005292 c40da18c .config console log report ci2-upstream-kcsan-gce
2020/01/19 15:19 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2020/01/18 22:18 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2020/01/16 11:37 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/15 18:25 https://github.com/google/ktsan.git kcsan 245a43005292 f9b69507 .config console log report ci2-upstream-kcsan-gce
2020/01/15 15:41 https://github.com/google/ktsan.git kcsan 245a43005292 069a5a44 .config console log report ci2-upstream-kcsan-gce
2020/01/14 19:39 https://github.com/google/ktsan.git kcsan 245a43005292 fa12bd3c .config console log report ci2-upstream-kcsan-gce
2020/01/13 23:08 https://github.com/google/ktsan.git kcsan 245a43005292 32881205 .config console log report ci2-upstream-kcsan-gce
2020/01/13 11:06 https://github.com/google/ktsan.git kcsan 245a43005292 99565c1a .config console log report ci2-upstream-kcsan-gce
2020/01/12 22:36 https://github.com/google/ktsan.git kcsan 245a43005292 53faa9fe .config console log report ci2-upstream-kcsan-gce
2020/01/12 11:35 https://github.com/google/ktsan.git kcsan 245a43005292 31290a45 .config console log report ci2-upstream-kcsan-gce
2020/01/11 02:45 https://github.com/google/ktsan.git kcsan 245a43005292 4c04afaa .config console log report ci2-upstream-kcsan-gce
2020/01/10 14:37 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config console log report ci2-upstream-kcsan-gce
2020/01/09 15:42 https://github.com/google/ktsan.git kcsan 245a43005292 4de4e9f0 .config console log report ci2-upstream-kcsan-gce
2020/01/08 10:03 https://github.com/google/ktsan.git kcsan 245a43005292 ddc3e859 .config console log report ci2-upstream-kcsan-gce
2020/01/07 22:07 https://github.com/google/ktsan.git kcsan 245a43005292 6738e0b3 .config console log report ci2-upstream-kcsan-gce
2020/01/07 09:18 https://github.com/google/ktsan.git kcsan 245a43005292 1bcd407e .config console log report ci2-upstream-kcsan-gce
2020/01/06 20:15 https://github.com/google/ktsan.git kcsan 245a43005292 53430d97 .config console log report ci2-upstream-kcsan-gce
2019/10/23 02:25 https://github.com/google/ktsan.git kcsan 05f2236801fe d0686497 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.