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: 546d, last: 14h11m
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 546d 1124d 0/24 closed as invalid on 2021/06/07 13:54
upstream KCSAN: data-race in pcpu_alloc / pcpu_free_area 2 1149d 1158d 0/24 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 (620):
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 2022/12/05 17:19 upstream 76dcd734eca2 045cbb84 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/12/05 04:39 upstream 0ba09b173387 e080de16 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/12/04 02:01 upstream c2bf05db6c78 e080de16 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/30 12:14 upstream 01f856ae6d0c 4c2a66e8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/29 07:46 upstream ca57f02295f1 ca9683b8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/29 03:17 upstream b7b275e60bcd ca9683b8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/28 03:06 upstream b7b275e60bcd f4470a7b .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/27 09:11 upstream faf68e3523c2 f4470a7b .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/25 19:32 upstream 08ad43d554ba 74a66371 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/25 02:44 upstream c3eb11fbb826 74a66371 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/24 04:01 upstream 4312098baf37 52fdf57a .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/23 09:03 upstream eb7081409f94 52fdf57a .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/21 04:25 upstream eb7081409f94 5bb70014 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/20 17:21 upstream 77c51ba552a1 5bb70014 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/20 01:34 upstream fe24a97cf254 5bb70014 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/17 08:07 upstream cc675d22e422 3a127a31 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/16 18:06 upstream 59d0d52c30d4 3a127a31 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/15 22:55 upstream 81e7cfa3a9eb 3a127a31 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/14 08:39 upstream 094226ad94f4 7ba4d859 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/13 17:08 upstream af7a05689189 7ba4d859 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/13 02:31 upstream fef7fd48922d f42ee5d8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/12 08:56 upstream 8f2975c2bb4c f42ee5d8 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/10 19:58 upstream 1767a722a708 3ead01ad .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/10 16:46 upstream f67dd6ce0723 3ead01ad .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/10 02:48 upstream f67dd6ce0723 b2488a87 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/09 23:50 upstream f67dd6ce0723 bebca8b7 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/09 13:49 upstream f141df371335 bebca8b7 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/09 00:49 upstream f141df371335 5fa28208 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/08 21:46 upstream f141df371335 060f945e .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/08 08:08 upstream 59f2f4b8a757 6feb842b .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/06 22:06 upstream 089d1c31224e 6d752409 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/05 14:22 upstream b208b9fbbcba 6d752409 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/05 02:56 upstream 64c3dd0b98f5 6d752409 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/04 21:31 upstream ee6050c8af96 6d752409 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/03 21:32 upstream f2f32f8af2b0 6d752409 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/03 20:29 upstream f2f32f8af2b0 7a2ebf95 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/03 07:13 upstream 8e5423e991e8 7a2ebf95 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/02 19:28 upstream 8f71a2b3f435 08977f5d .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/01 22:58 upstream f526d6a82242 08977f5d .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/11/01 03:38 upstream 5aaef24b5c6d a1d8560a .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/31 14:45 upstream 30a0b95b1335 2a71366b .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/30 21:59 upstream b72018ab8236 2a71366b .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/29 04:18 upstream 576e61cea1e4 899d812a .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/28 18:30 upstream 05c31d25cc96 8168b69e .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/28 12:39 upstream 23758867219c 8168b69e .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/28 00:04 upstream 23758867219c 5c716ff6 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/25 22:58 upstream 1a2dcbdde82e 2159e4d2 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/25 04:46 upstream 337a0a0b63f1 45645420 .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/24 09:14 upstream 247f34f7b803 faae2fda .config log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2022/10/24 07:15 upstream 247f34f7b803 23bf86af .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
* Struck through repros no longer work on HEAD.