syzbot


KCSAN: data-race in pcpu_alloc / pcpu_free_area (3)

Status: moderation: reported syz repro on 2021/11/29 17:24
Reported-by: syzbot+041c26cb85794b7e414d@syzkaller.appspotmail.com
First crash: 391d, last: 4h48m
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pcpu_alloc / pcpu_free_area (2) 574 392d 970d 0/22 closed as invalid on 2021/06/07 13:54
upstream KCSAN: data-race in pcpu_alloc / pcpu_free_area 2 995d 1004d 0/22 closed as invalid on 2019/10/15 15:50

Sample crash report:
==================================================================
BUG: KCSAN: data-race in pcpu_alloc / pcpu_free_area

read-write to 0xffffffff86e8f9bc of 4 bytes by interrupt on cpu 0:
 pcpu_update_empty_pages mm/percpu.c:606 [inline]
 pcpu_block_update_hint_free mm/percpu.c:1040 [inline]
 pcpu_free_area+0x52a/0x5c0 mm/percpu.c:1298
 free_percpu+0x1d5/0xa50 mm/percpu.c:2281
 free_vfsmnt fs/namespace.c:612 [inline]
 delayed_free_vfsmnt+0xa3/0xe0 fs/namespace.c:619
 rcu_do_batch kernel/rcu/tree.c:2535 [inline]
 rcu_core+0x57e/0xbb0 kernel/rcu/tree.c:2786
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2803
 __do_softirq+0x158/0x2e3 kernel/softirq.c:558
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:921
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffffffff86e8f9bc of 4 bytes by task 2063 on cpu 1:
 pcpu_alloc+0x9bb/0xfb0 mm/percpu.c:1877
 __alloc_percpu+0x20/0x30 mm/percpu.c:1949
 alloc_vfsmnt+0xcf/0x2e0 fs/namespace.c:214
 clone_mnt+0x40/0x880 fs/namespace.c:1104
 copy_tree+0x313/0x870 fs/namespace.c:1921
 copy_mnt_ns+0x116/0x600 fs/namespace.c:3480
 create_new_namespaces+0x88/0x450 kernel/nsproxy.c:78
 unshare_nsproxy_namespaces+0xe2/0x120 kernel/nsproxy.c:226
 ksys_unshare+0x38c/0x6e0 kernel/fork.c:3132
 __do_sys_unshare kernel/fork.c:3203 [inline]
 __se_sys_unshare kernel/fork.c:3201 [inline]
 __x64_sys_unshare+0x1b/0x20 kernel/fork.c:3201
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000005 -> 0x00000006

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2063 Comm: syz-executor.0 Not tainted 5.18.0-rc7-syzkaller-00136-g3b5e1590a267-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (428):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/21 17:04 upstream 3b5e1590a267 7268fa62 .config log report syz KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/07/04 19:12 upstream c1084b6c5620 bff65f44 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/07/04 10:39 upstream 88084a3df167 1434eec0 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/07/03 17:32 upstream 20855e4cb361 1434eec0 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/07/02 12:36 upstream 089866061428 1434eec0 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/30 20:30 upstream 1a0e93df1e10 1434eec0 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/29 20:16 upstream d9b2ba67917c 1434eec0 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/26 18:53 upstream 82708bb1eb9e a371c43c .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/25 21:30 upstream 0840a7914caa a371c43c .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/24 19:11 upstream 38bc4ac43168 a371c43c .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/24 07:35 upstream 92f20ff72066 a5dbd430 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/23 08:48 upstream de5c208d533a 912f5df7 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/22 16:30 upstream ca1fdab7fd27 912f5df7 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/21 19:12 upstream ca1fdab7fd27 0fc5c330 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/20 19:34 upstream 78ca55889a54 b9406563 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/20 12:44 upstream a111daf0c53a b9406563 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/20 05:50 upstream a111daf0c53a 8f633d84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/19 17:03 upstream 05c6ca8512f2 8f633d84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/19 03:43 upstream 354c6e071be9 8f633d84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/18 09:08 upstream 4b35035bcf80 8f633d84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/17 19:37 upstream 462abc9de7a1 8f633d84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/17 06:49 upstream 47700948a4ab cb58b3b2 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/16 01:50 upstream 30306f6194ca 1719ee24 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/15 11:26 upstream 018ab4fabddd 1719ee24 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/15 06:59 upstream 018ab4fabddd 127d1faf .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/14 13:52 upstream b13baccc3850 127d1faf .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/13 17:06 upstream b13baccc3850 0f087040 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/13 09:02 upstream b13baccc3850 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/12 19:31 upstream 997952851843 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/12 03:22 upstream 7a68065eb9cd 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/11 14:26 upstream 0885eacdc81f 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/11 00:57 upstream a32e7ea36235 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/10 11:48 upstream 874c8ca1e60b 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/09 21:43 upstream 3d9f55c57bc3 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/08 18:39 upstream 34f4335c16a5 0d5abf15 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/08 17:15 upstream 34f4335c16a5 b2706118 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/08 02:13 upstream 9886142c7a22 b2706118 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/07 16:28 upstream e71e60cd74df b2706118 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/05 15:08 upstream 952923ddc011 c8857892 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/05 02:00 upstream d0e60d46bc03 c8857892 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/04 13:08 upstream 032dcf09e2bf c8857892 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/03 23:37 upstream 744983d87842 c8857892 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/02 23:16 upstream 58f9d52ff689 02dddea8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/02 10:27 upstream d1dc87763f40 6e12f05f .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/01 18:38 upstream 8eca6b0a647a b4bc6a3d .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/01 15:44 upstream 700170bf6b4d b4bc6a3d .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/06/01 11:11 upstream 700170bf6b4d 3666edfe .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/05/31 09:50 upstream 8ab2afa23bd1 af70c3a9 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2021/11/29 14:18 upstream d58071a8a76d 63eeac02 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2021/11/28 23:18 upstream d06c942efea4 63eeac02 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2021/06/08 01:37 upstream 614124bea77e b718257f .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area