syzbot


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

Status: moderation: reported syz repro on 2021/11/29 17:24
Subsystems: netfilter (incorrect?)
Reported-by: syzbot+041c26cb85794b7e414d@syzkaller.appspotmail.com
First crash: 661d, last: 10h02m
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 661d 1239d 0/24 closed as invalid on 2021/06/07 13:54
upstream KCSAN: data-race in pcpu_alloc / pcpu_free_area 2 1264d 1273d 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 (763):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2022/05/21 17:04 upstream 3b5e1590a267 7268fa62 .config console log report syz KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/30 20:07 upstream 8bb95a1662f8 f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/29 09:36 upstream fcd476ea6a88 f325deb0 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/28 22:39 upstream fcd476ea6a88 fc067f05 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/27 23:17 upstream 3a93e40326c8 47f3aaf1 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/27 10:50 upstream 197b6b60ae7b f8f96aa9 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/26 22:05 upstream 0ec57cfa721f fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/25 14:12 upstream 65aca32efdcb fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/25 04:40 upstream 65aca32efdcb 9700afae .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/24 10:37 upstream 1e760fa3596e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/23 02:19 upstream fff5a5e7f528 f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/22 16:41 upstream a1effab7a3a3 f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/22 09:16 upstream a1effab7a3a3 8b4eb097 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/21 19:52 upstream 2faac9a98f01 8b4eb097 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/21 09:57 upstream 17214b70a159 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/19 23:19 upstream e8d018dd0257 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/19 13:50 upstream a3671bd86a97 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/18 20:27 upstream 534293368afa 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/18 10:27 upstream 478a351ce0d6 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/17 18:24 upstream 38e04b3e4240 7939252e .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/16 19:42 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/15 22:11 upstream 9c1bec9c0b08 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/14 20:24 upstream 4979bf866825 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/14 09:30 upstream fc89d7fb499b 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/14 01:32 upstream fc89d7fb499b 026e2200 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/13 12:03 upstream eeac8ede1755 026e2200 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/12 17:11 upstream 134231664868 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/11 21:22 upstream 81ff855485a3 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/11 12:54 upstream ef5f68cc1f82 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/08 21:40 upstream 6a98c9cae232 4fc6d98d .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/08 15:57 upstream 63355b9884b3 4fc6d98d .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/08 03:25 upstream 63355b9884b3 d2b00170 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/07 22:48 upstream 63355b9884b3 d7ea8bc4 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/07 15:06 upstream 8ca09d5fa354 d7ea8bc4 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/07 11:18 upstream 8ca09d5fa354 ffaa5c55 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/06 10:03 upstream fe15c26ee26e f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/05 20:25 upstream f915322fe014 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/05 02:52 upstream b01fe98d34f3 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/04 11:34 upstream 0988a0ea7919 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/03 22:28 upstream 0a3f9a6b0265 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/03 08:54 upstream 2eb29d59ddf0 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/02 19:24 upstream 04a357b1f6f0 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/01 21:01 upstream ee3f96b16468 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/01 13:43 upstream c0927a7a5391 ef65e6cb .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2023/03/01 00:49 upstream e492250d5252 95aee97a .config console log report info [disk image] [vmlinux] [kernel image] KCSAN: data-race in pcpu_alloc / pcpu_free_area
ci2-upstream-kcsan-gce 2021/11/29 14:18 upstream d58071a8a76d 63eeac02 .config console 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 console 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 console log report info KCSAN: data-race in pcpu_alloc / pcpu_free_area
* Struck through repros no longer work on HEAD.