syzbot


KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault (2)

Status: auto-closed as invalid on 2021/01/03 02:26
Reported-by: syzbot+c5797dc7117f882f94a4@syzkaller.appspotmail.com
First crash: 631d, last: 625d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault (4) 1 513d 513d 0/23 auto-closed as invalid on 2021/04/25 00:05
upstream KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault (5) 1 478d 477d 0/23 auto-closed as invalid on 2021/05/30 07:22
upstream KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault 1 730d 730d 0/23 auto-closed as invalid on 2020/09/20 08:31
upstream KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault (3) 1 560d 560d 0/23 auto-closed as invalid on 2021/03/09 10:11

Sample crash report:
==================================================================
BUG: KCSAN: data-race in cgroup_procs_write_start / handle_mm_fault

write to 0xffff888019dd44c0 of 2 bytes by task 20518 on cpu 1:
 mem_cgroup_exit_user_fault include/linux/memcontrol.h:659 [inline]
 handle_mm_fault+0x1462/0x1770 mm/memory.c:4610
 do_user_addr_fault+0x33e/0x730 arch/x86/mm/fault.c:1372
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1485
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583

read to 0xffff888019dd44c0 of 2 bytes by task 1 on cpu 0:
 cgroup_procs_write_start+0x13c/0x270 kernel/cgroup/cgroup.c:2795
 __cgroup1_procs_write+0x5d/0x220 kernel/cgroup/cgroup-v1.c:500
 cgroup1_procs_write+0x26/0x30 kernel/cgroup/cgroup-v1.c:532
 cgroup_file_write+0x173/0x2f0 kernel/cgroup/cgroup.c:3699
 kernfs_fop_write+0x207/0x2c0 fs/kernfs/file.c:315
 vfs_write+0x21a/0x7c0 fs/read_write.c:603
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1 Comm: systemd Not tainted 5.10.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/11/29 02:25 upstream 67f34fa8893e a0092f9d .config log report info
ci2-upstream-kcsan-gce 2020/11/23 11:11 upstream 418baf2c28f3 0d27f508 .config log report info