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KCSAN: data-race in setattr_copy / vfs_getattr_nosec

Status: auto-closed as invalid on 2021/06/05 13:09
Subsystems: fs
[Documentation on labels]
First crash: 1581d, last: 1575d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in setattr_copy / vfs_getattr_nosec (2) fs 6 1 1540d 1540d 0/29 auto-closed as invalid on 2021/07/10 19:21
upstream KCSAN: data-race in setattr_copy / vfs_getattr_nosec (3) fs 6 1 1459d 1459d 0/29 auto-closed as invalid on 2021/09/29 03:05
upstream KCSAN: data-race in setattr_copy / vfs_getattr_nosec (4) fs 6 1 1348d 1348d 0/29 auto-closed as invalid on 2022/01/18 19:17

Sample crash report:
 loop2: p1 p2 < > p3 p4 < p5 p6 >
loop2: p1 size 11290111 extends beyond EOD, truncated
loop2: p3 size 1914664839 extends beyond EOD, truncated
loop2: p5 size 11290111 extends beyond EOD, truncated
loop2: p6 size 1914664839 extends beyond EOD, truncated
==================================================================
BUG: KCSAN: data-race in setattr_copy / vfs_getattr_nosec

write to 0xffff88812dad7070 of 2 bytes by task 19 on cpu 0:
 setattr_copy+0x1af/0x1c0 fs/attr.c:247
 shmem_setattr+0xb0/0x450 mm/shmem.c:1118
 notify_change+0x8a3/0xa80 fs/attr.c:398
 handle_remove drivers/base/devtmpfs.c:333 [inline]
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop+0x783/0x8d0 drivers/base/devtmpfs.c:395
 devtmpfsd+0x3f/0x40 drivers/base/devtmpfs.c:437
 kthread+0x1d0/0x1f0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff88812dad7070 of 2 bytes by task 24213 on cpu 1:
 generic_fillattr fs/stat.c:48 [inline]
 vfs_getattr_nosec+0x1a5/0x2f0 fs/stat.c:108
 vfs_getattr fs/stat.c:142 [inline]
 vfs_statx+0x128/0x290 fs/stat.c:207
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_stat include/linux/fs.h:3382 [inline]
 __do_sys_newstat fs/stat.c:367 [inline]
 __se_sys_newstat+0x46/0x250 fs/stat.c:363
 __x64_sys_newstat+0x2d/0x40 fs/stat.c:363
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24213 Comm: syz-executor.2 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
loop2: detected capacity change from 0 to 264192
 loop2: p1 p2 < > p3 p4 < p5 p6 >
loop2: p1 size 11290111 extends beyond EOD, truncated
loop2: p3 size 1914664839 extends beyond EOD, truncated
loop2: p5 size 11290111 extends beyond EOD, truncated
loop2: p6 size 1914664839 extends beyond EOD, truncated

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/05/01 13:09 upstream 9f67672a817e 77e2b668 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in setattr_copy / vfs_getattr_nosec
2021/04/26 01:21 upstream d2d09fbe33f8 2a82f1b3 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in setattr_copy / vfs_getattr_nosec
2021/04/24 22:10 upstream 2a1d7946fa53 17f0b706 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in setattr_copy / vfs_getattr_nosec
* Struck through repros no longer work on HEAD.