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KCSAN: data-race in ext4_trim_fs / mb_mark_used

Status: auto-closed as invalid on 2021/05/23 04:19
Subsystems: ext4
[Documentation on labels]
First crash: 1076d, last: 1076d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_trim_fs / mb_mark_used

write to 0xffff8881013da884 of 4 bytes by task 26169 on cpu 1:
 mb_mark_used+0x13c/0xc40 fs/ext4/mballoc.c:1607
 ext4_trim_extent+0xb8/0x410 fs/ext4/mballoc.c:5680
 ext4_trim_all_free+0x388/0x890 fs/ext4/mballoc.c:5741
 ext4_trim_fs+0x3f3/0x520 fs/ext4/mballoc.c:5847
 __ext4_ioctl fs/ext4/ioctl.c:1126 [inline]
 ext4_ioctl+0x12e6/0x2c00 fs/ext4/ioctl.c:1332
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881013da884 of 4 bytes by task 26185 on cpu 0:
 ext4_trim_fs+0x3af/0x520 fs/ext4/mballoc.c:5846
 __ext4_ioctl fs/ext4/ioctl.c:1126 [inline]
 ext4_ioctl+0x12e6/0x2c00 fs/ext4/ioctl.c:1332
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26185 Comm: syz-executor.5 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/18 04:14 upstream 194cf4825638 7e2b734b .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in ext4_trim_fs / mb_mark_used
* Struck through repros no longer work on HEAD.