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KCSAN: data-race in data_push_tail / vsnprintf (9)

Status: moderation: reported on 2025/02/21 08:47
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+504460beb7923d347fba@syzkaller.appspotmail.com
First crash: 542d, last: 4d15h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
60acfae2-9f5e-4737-8098-8ee8f04236b4 repro 💥 KCSAN: data-race in data_push_tail / vsnprintf (9) 2026/03/10 00:57 2026/03/10 00:57 2026/03/10 01:07 6972f30219093b03bcc1a54487e12a7097245c01 Error 429, Message: You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. , Status: RESOURCE_EXHAUSTED, Details: [map[@type:type.googleapis.com/google.rpc.Help links:[map[description:Learn more about Gemini API quotas url:https://ai.google.dev/gemini-api/docs/rate-limits]]] map[@type:type.googleapis.com/google.rpc.DebugInfo detail:[ORIGINAL ERROR] generic::resource_exhausted: You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. [google.rpc.error_details_ext] { message: "You exceeded your current quota, please check your plan and billing details. For more information on this error, head to: https://ai.google.dev/gemini-api/docs/rate-limits. To monitor your current usage, head to: https://ai.dev/rate-limit. " details { type_url: "type.googleapis.com/language_labs.genai.debug.GeminiApiDebugInfo" value: "R\212\001\n\207\001\nTgenerativelanguage.googleapis.com/generate_content_paid_tier_1_input_tokens_internal\022\022\n\010location\022\006global\022\027\n\005model\022\016gemini-3.1-pro\030\300\204=" } details { [type.googleapis.com/google.rpc.Help] { links { description: "Learn more about Gemini API quotas" url: "https://ai.google.dev/gemini-api/docs/rate-limits" } } } }]]
c7f53763-1149-4d54-8708-f3af8cb3f519 assessment-kcsan Benign: ✅  ❓ KCSAN: data-race in data_push_tail / vsnprintf (9) 2026/01/10 08:50 2026/01/10 08:50 2026/01/10 08:55 7519916073b761ced56a7b15fdeeb4674e8dc125
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in data_push_tail / vsnprintf (6) ext4 6 23 784d 864d 0/29 auto-obsoleted due to no activity on 2024/03/31 12:46
upstream KCSAN: data-race in data_push_tail / vsnprintf (4) ext4 6 4 1117d 1205d 0/29 auto-obsoleted due to no activity on 2023/05/03 19:58
upstream KCSAN: data-race in data_push_tail / vsnprintf (3) kernel 6 8 1328d 1427d 0/29 auto-closed as invalid on 2022/10/04 16:48
upstream KCSAN: data-race in data_push_tail / vsnprintf (7) block batman 6 2 711d 738d 0/29 auto-obsoleted due to no activity on 2024/06/13 03:32
upstream KCSAN: data-race in data_push_tail / vsnprintf (2) ext4 6 1 1485d 1485d 0/29 auto-closed as invalid on 2022/05/01 03:50
upstream KCSAN: data-race in data_push_tail / vsnprintf (5) block net 6 2 1027d 1055d 0/29 closed as invalid on 2023/06/28 10:46
upstream KCSAN: data-race in data_push_tail / vsnprintf (8) ext4 bridge 6 4 613d 651d 0/29 auto-obsoleted due to no activity on 2024/09/19 07:21
upstream KCSAN: data-race in data_push_tail / vsnprintf usb 6 36 1549d 1862d 0/29 auto-closed as invalid on 2022/02/26 00:52

Sample crash report:
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff893a1708 of 12 bytes by task 29601 on cpu 1:
 vsnprintf+0x2ce/0x860 lib/vsprintf.c:2899
 vscnprintf+0x41/0x90 lib/vsprintf.c:3013
 printk_sprint+0x30/0x2b0 kernel/printk/printk.c:2222
 vprintk_store+0x57b/0x910 kernel/printk/printk.c:2364
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 p9_fd_create_tcp+0x3da/0x430 net/9p/trans_fd.c:921
 p9_client_create+0x231/0x770 net/9p/client.c:894
 v9fs_session_init+0x3c/0x4a0 fs/9p/v9fs.c:442
 v9fs_get_tree+0x5c/0x5e0 fs/9p/vfs_super.c:97
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3834
 path_mount+0x4d0/0xbc0 fs/namespace.c:4154
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff893a1708 of 8 bytes by task 29597 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:608 [inline]
 data_push_tail+0x100/0x470 kernel/printk/printk_ringbuffer.c:693
 data_alloc+0x11b/0x390 kernel/printk/printk_ringbuffer.c:1089
 prb_reserve+0x8d7/0xae0 kernel/printk/printk_ringbuffer.c:1724
 vprintk_store+0x54a/0x910 kernel/printk/printk.c:2354
 vprintk_emit+0x1a4/0x600 kernel/printk/printk.c:2455
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2494
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2504
 p9_fd_create_tcp+0x3da/0x430 net/9p/trans_fd.c:921
 p9_client_create+0x231/0x770 net/9p/client.c:894
 v9fs_session_init+0x3c/0x4a0 fs/9p/v9fs.c:442
 v9fs_get_tree+0x5c/0x5e0 fs/9p/vfs_super.c:97
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3834
 path_mount+0x4d0/0xbc0 fs/namespace.c:4154
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4360
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4360
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000001000019a5 -> 0x5f74656e70393301

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 29597 Comm: syz.0.5471 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
==================================================================
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1
9pnet_fd: p9_fd_create_tcp (29597): problem connecting socket to 127.0.0.1

Crashes (217):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/15 15:50 upstream 1f5ffc672165 c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/04/07 21:26 upstream 3036cd0d3328 628666c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/04/07 14:58 upstream bfe62a454542 628666c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/04/04 17:14 upstream 7ca6d1cfec80 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/04/04 02:23 upstream 631919fb12fe 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/30 12:44 upstream 7aaa8047eafd dcaebc52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/29 00:21 upstream cbfffcca2bf0 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/25 18:12 upstream bbeb83d3182a 8ee77f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/21 14:35 upstream 42bddab0563f 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/19 08:54 upstream 8a30aeb0d1b4 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/18 17:03 upstream a989fde763f4 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/11 11:32 upstream b4f0dd314b39 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/09 12:54 upstream 1f318b96cc84 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/03/08 08:21 upstream c23719abc330 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/25 21:08 upstream d9d32e5bd5a4 94a9671e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/25 12:52 upstream 7dff99b35460 94a9671e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/25 05:51 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/19 09:14 upstream 956b9cbd7f15 746545b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/18 04:57 upstream 2961f841b025 39751c21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/17 15:19 upstream 970296997869 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/15 08:11 upstream 3e48a11675c5 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/14 16:47 upstream 770aaedb461a 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/12 05:47 upstream c22e26bd0906 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/07 07:29 upstream 2687c848e578 f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/06 18:21 upstream b7ff7151e653 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/06 08:15 upstream 8fdb05de0e2d f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/05 12:50 upstream f14faaf3a1fb 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/02 02:43 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/02/01 17:14 upstream ad9a728a3388 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/31 09:40 upstream 283073725700 c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/30 17:32 upstream 4d310797262f ae7dc18c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/29 12:49 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/29 03:49 upstream 8dfce8991b95 0adc945e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/28 00:01 upstream 1f97d9dcf536 3029c699 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/26 15:01 upstream 63804fed149a a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/25 08:30 upstream 5dbeeb268b63 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/20 04:56 upstream 24d479d26b25 572effc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/19 20:30 upstream 24d479d26b25 a9fc5226 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/18 02:57 upstream d12453c7e281 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/15 01:35 upstream e0d4140e8043 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/13 09:45 upstream b71e635feefc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/09 09:41 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/09 00:44 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/08 08:10 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/06 01:58 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2026/01/04 08:02 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/12/30 00:42 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/12/28 15:45 upstream d26143bb38e2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/12/25 01:44 upstream ccd1cdca5cd4 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/12/17 10:13 upstream ea1013c15392 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/02/07 10:10 upstream bb066fe812d6 53657d1b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
* Struck through repros no longer work on HEAD.