KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next

KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next_owner (3)
Status: auto-closed as invalid on 2021/01/20 08:48
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 279d, last: 279d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next_owner (4)	7	112d	171d	0/22	auto-closed as invalid on 2021/07/06 03:43
upstream	KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next_owner (2)	2	355d	369d	0/22	auto-closed as invalid on 2020/11/04 12:23
upstream	KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next_owner	1	410d	410d	0/22	auto-closed as invalid on 2020/09/10 17:38

Sample crash report:

==================================================================
BUG: KCSAN: data-race in capable_wrt_inode_uidgid / mm_update_next_owner

read-write to 0xffff8880119f102c of 4 bytes by task 27334 on cpu 1:
 ns_capable_common kernel/capability.c:377 [inline]
 ns_capable kernel/capability.c:396 [inline]
 capable_wrt_inode_uidgid+0x95/0x120 kernel/capability.c:506
 generic_permission+0x19b/0x3e0 fs/namei.c:381
 do_inode_permission fs/namei.c:405 [inline]
 inode_permission+0x6c/0x320 fs/namei.c:463
 may_open+0x19f/0x2e0 fs/namei.c:2875
 do_open fs/namei.c:3250 [inline]
 path_openat+0x17ac/0x20a0 fs/namei.c:3369
 do_filp_open+0xbd/0x1d0 fs/namei.c:3396
 do_sys_openat2+0xa3/0x240 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_open fs/open.c:1196 [inline]
 __se_sys_open fs/open.c:1192 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1192
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880119f102c of 4 bytes by task 27340 on cpu 0:
 mm_update_next_owner+0x1d9/0x4e0 kernel/exit.c:387
 exit_mm+0x327/0x420 kernel/exit.c:499
 do_exit+0x3c8/0x1630 kernel/exit.c:810
 do_group_exit+0x16f/0x170 kernel/exit.c:920
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:931
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:929
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:929
 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: 27340 Comm: syz-executor.4 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/12/16 08:44	upstream	d01e7f10dae2	649595c6	.config	log	report			info