KCSAN: data-race in common_perm_cond / kernfs_refresh_inode

Status: auto-closed as invalid on 2020/04/15 17:43
Subsystems: apparmor
[Documentation on labels]
First crash: 2474d, last: 2403d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in common_perm_cond / kernfs_refresh_inode

read to 0xffff88812a7270c0 of 2 bytes by task 20853 on cpu 0:
 common_perm_cond+0x74/0x110 security/apparmor/lsm.c:228
 apparmor_inode_getattr+0x2b/0x40 security/apparmor/lsm.c:399
 security_inode_getattr+0x9b/0xd0 security/security.c:1222
 vfs_getattr+0x2e/0x70 fs/stat.c:115
 vfs_statx_fd+0x7a/0xd0 fs/stat.c:145
 vfs_fstat include/linux/fs.h:3265 [inline]
 __do_sys_newfstat+0x49/0xa0 fs/stat.c:378
 __se_sys_newfstat fs/stat.c:375 [inline]
 __x64_sys_newfstat+0x3a/0x50 fs/stat.c:375
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88812a7270c0 of 2 bytes by task 3990 on cpu 1:
 kernfs_refresh_inode+0x42/0x140 fs/kernfs/inode.c:172
 kernfs_iop_getattr+0x68/0x90 fs/kernfs/inode.c:191
 vfs_getattr_nosec+0x12e/0x170 fs/stat.c:81
 vfs_getattr+0x54/0x70 fs/stat.c:118
 vfs_statx+0x102/0x190 fs/stat.c:191
 vfs_stat include/linux/fs.h:3249 [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/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3990 Comm: udevd Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/02/05 17:39 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2020/01/25 07:17 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2020/01/16 14:30 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/11 02:45 https://github.com/google/ktsan.git kcsan 245a43005292 4c04afaa .config console log report ci2-upstream-kcsan-gce
2019/12/20 10:15 https://github.com/google/ktsan.git kcsan 245a43005292 36650b4b .config console log report ci2-upstream-kcsan-gce
2019/12/18 19:31 https://github.com/google/ktsan.git kcsan 245a43005292 79b211f7 .config console log report ci2-upstream-kcsan-gce
2019/12/18 09:40 https://github.com/google/ktsan.git kcsan 245a43005292 64ca0a37 .config console log report ci2-upstream-kcsan-gce
2019/12/10 04:28 https://github.com/google/ktsan.git kcsan ef798c30ba4e 4b83c8fb .config console log report ci2-upstream-kcsan-gce
2019/11/30 23:38 https://github.com/google/ktsan.git kcsan ef798c30ba4e a76bf83f .config console log report ci2-upstream-kcsan-gce
2019/11/27 10:23 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1048481f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.