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KCSAN: data-race in copy_process / task_dump_owner

Status: auto-closed as invalid on 2020/02/14 20:26
Subsystems: fs
[Documentation on labels]
First crash: 1880d, last: 1880d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_process / task_dump_owner (3) kernel 75 1336d 1348d 0/28 auto-closed as invalid on 2021/07/07 09:32
upstream KCSAN: data-race in copy_process / task_dump_owner (2) kernel 6 1572d 1660d 0/28 auto-closed as invalid on 2020/11/13 22:51

Sample crash report:
==================================================================
BUG: KCSAN: data-race in copy_process / task_dump_owner

read to 0xffff8880b2d55024 of 4 bytes by task 7638 on cpu 1:
 task_dump_owner+0x43/0x260 fs/proc/base.c:1698
 pid_update_inode+0x3c/0x70 fs/proc/base.c:1818
 pid_revalidate+0x91/0xd0 fs/proc/base.c:1841
 d_revalidate fs/namei.c:758 [inline]
 d_revalidate fs/namei.c:755 [inline]
 lookup_fast+0x6f2/0x700 fs/namei.c:1607
 walk_component+0x6d/0xe70 fs/namei.c:1796
 lookup_last fs/namei.c:2263 [inline]
 path_lookupat.isra.0+0x13a/0x5a0 fs/namei.c:2308
 filename_lookup+0x145/0x2b0 fs/namei.c:2338
 user_path_at_empty+0x4c/0x70 fs/namei.c:2598
 user_path_at include/linux/namei.h:49 [inline]
 vfs_statx+0xd9/0x190 fs/stat.c:187
 vfs_stat include/linux/fs.h:3242 [inline]
 __do_sys_newstat+0x51/0xb0 fs/stat.c:341
 __se_sys_newstat fs/stat.c:337 [inline]
 __x64_sys_newstat+0x3a/0x50 fs/stat.c:337
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b2d55024 of 4 bytes by task 7588 on cpu 0:
 copy_process+0x916/0x3b50 kernel/fork.c:1882
 _do_fork+0xfe/0x6e0 kernel/fork.c:2366
 __do_sys_clone kernel/fork.c:2521 [inline]
 __se_sys_clone kernel/fork.c:2502 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2502
 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: 7588 Comm: udevd Not tainted 5.4.0-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
2019/12/06 20:21 https://github.com/google/ktsan.git kcsan ef798c30ba4e 85f26751 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.