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KCSAN: data-race in other_inode_match / writeback_single_inode

Status: closed as invalid on 2020/01/09 14:13
Subsystems: ext4
[Documentation on labels]
First crash: 1892d, last: 1861d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in other_inode_match / writeback_single_inode (2) ext4 17 1689d 1844d 0/28 closed as invalid on 2020/06/18 14:24

Sample crash report:
==================================================================
BUG: KCSAN: data-race in other_inode_match / writeback_single_inode

write to 0xffff88812564cac0 of 8 bytes by task 9037 on cpu 1:
 writeback_single_inode+0x214/0x310 fs/fs-writeback.c:1562
 sync_inode fs/fs-writeback.c:2602 [inline]
 sync_inode_metadata+0x74/0xa0 fs/fs-writeback.c:2622
 ext4_fsync_nojournal fs/ext4/fsync.c:94 [inline]
 ext4_sync_file+0x4b5/0xaf0 fs/ext4/fsync.c:172
 vfs_fsync_range+0x82/0x150 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2856 [inline]
 ext4_buffered_write_iter+0x222/0x290 fs/ext4/file.c:259
 ext4_file_write_iter+0xf4/0xd40 fs/ext4/file.c:547
 call_write_iter include/linux/fs.h:1902 [inline]
 do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x13b/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 ovl_write_iter+0x366/0x550 fs/overlayfs/file.c:278
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 __kernel_write+0xb8/0x240 fs/read_write.c:515
 write_pipe_buf+0xb6/0xf0 fs/splice.c:809
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x295/0x4a0 fs/splice.c:636
 splice_from_pipe+0xbb/0x100 fs/splice.c:671
 default_file_splice_write+0x45/0x90 fs/splice.c:821
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1519 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812564cac0 of 8 bytes by task 7883 on cpu 0:
 other_inode_match+0x6b/0x5c0 fs/ext4/inode.c:4820
 find_inode_nowait+0x135/0x160 fs/inode.c:1437
 ext4_update_other_inodes_time fs/ext4/inode.c:4868 [inline]
 ext4_do_update_inode fs/ext4/inode.c:4994 [inline]
 ext4_mark_iloc_dirty+0x12a8/0x1580 fs/ext4/inode.c:5547
 ext4_mark_inode_dirty+0xe9/0x420 fs/ext4/inode.c:5740
 ext4_evict_inode+0x6ee/0xe50 fs/ext4/inode.c:312
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7883 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/24 06:12 https://github.com/google/ktsan.git kcsan 245a43005292 be5c2c81 .config console log report ci2-upstream-kcsan-gce
2019/11/23 23:32 https://github.com/google/ktsan.git kcsan 5863cc791e4c 598ca6c8 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.