syzbot


KCSAN: data-race in p9_client_cb / p9_client_rpc (7)

Status: auto-closed as invalid on 2022/05/08 15:40
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 270d, last: 239d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (3) 2 619d 650d 0/24 auto-closed as invalid on 2021/04/24 11:05
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (8) 1 118d 118d 0/24 auto-closed as invalid on 2022/09/07 10:12
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (4) 5 549d 561d 0/24 auto-closed as invalid on 2021/07/02 20:41
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (6) 1 425d 425d 0/24 auto-closed as invalid on 2021/11/04 05:57
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (5) 1 513d 513d 0/24 auto-closed as invalid on 2021/08/07 12:54
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (9) 1 82d 82d 0/24 auto-obsoleted due to no activity on 2022/10/12 13:20
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc (2) 1 868d 868d 0/24 auto-closed as invalid on 2020/08/17 23:12
upstream KCSAN: data-race in p9_client_cb / p9_client_rpc 2 1113d 1113d 0/24 auto-closed as invalid on 2020/01/21 10:36

Sample crash report:
==================================================================
BUG: KCSAN: data-race in p9_client_cb / p9_client_rpc

write to 0xffff8881387c5f68 of 4 bytes by task 10279 on cpu 0:
 p9_client_cb+0x14/0x40 net/9p/client.c:425
 p9_conn_cancel+0x3a1/0x400 net/9p/trans_fd.c:213
 p9_poll_mux net/9p/trans_fd.c:626 [inline]
 p9_poll_workfn+0x14c/0x410 net/9p/trans_fd.c:1146
 process_one_work+0x3e3/0x970 kernel/workqueue.c:2289
 worker_thread+0x638/0xaa0 kernel/workqueue.c:2436
 kthread+0x1bf/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffff8881387c5f68 of 4 bytes by task 13035 on cpu 1:
 p9_client_rpc+0x16f/0x690 net/9p/client.c:756
 p9_client_version+0xa0/0x350
 p9_client_create+0x620/0x750 net/9p/client.c:1056
 v9fs_session_init+0x100/0xcf0 fs/9p/v9fs.c:408
 v9fs_mount+0x57/0x520 fs/9p/vfs_super.c:126
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1497
 do_new_mount fs/namespace.c:3040 [inline]
 path_mount+0x11cf/0x1c40 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3568
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x50 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000002 -> 0x00000005

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13035 Comm: syz-executor.3 Not tainted 5.17.0-syzkaller-14079-gbe2d3ecedd99-dirty #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 2022/04/03 15:30 upstream be2d3ecedd99 79a2a8fc .config log report info KCSAN: data-race in p9_client_cb / p9_client_rpc
ci2-upstream-kcsan-gce 2022/03/03 12:31 upstream 5859a2b19911 45a13a73 .config log report info KCSAN: data-race in p9_client_cb / p9_client_rpc
* Struck through repros no longer work on HEAD.