syzbot


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

Status: moderation: reported on 2025/02/21 08:47
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+504460beb7923d347fba@syzkaller.appspotmail.com
First crash: 395d, last: 1d08h
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 636d 717d 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 969d 1057d 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 1180d 1279d 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 563d 590d 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 1337d 1337d 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 879d 908d 0/29 closed as invalid on 2023/06/28 10:46
upstream KCSAN: data-race in data_push_tail / vsnprintf (8) bridge ext4 6 4 465d 503d 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 1401d 1714d 0/29 auto-closed as invalid on 2022/02/26 00:52

Sample crash report:
==================================================================
BUG: KCSAN: data-race in data_push_tail / vsnprintf

write to 0xffffffff88e71d2b of 11 bytes by task 8109 on cpu 1:
 vsnprintf+0x2ce/0x890 lib/vsprintf.c:2878
 vscnprintf+0x41/0x90 lib/vsprintf.c:2991
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2189
 vprintk_store+0x599/0x860 kernel/printk/printk.c:2309
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 fail_dump lib/fault-inject.c:66 [inline]
 should_fail_ex+0x24d/0x280 lib/fault-inject.c:174
 should_failslab+0x8c/0xb0 mm/failslab.c:46
 slab_pre_alloc_hook mm/slub.c:4931 [inline]
 slab_alloc_node mm/slub.c:5264 [inline]
 __do_kmalloc_node mm/slub.c:5649 [inline]
 __kmalloc_noprof+0xa5/0x570 mm/slub.c:5662
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kmalloc_array_noprof include/linux/slab.h:1003 [inline]
 alloc_pipe_info+0x1c9/0x350 fs/pipe.c:817
 splice_direct_to_actor+0x592/0x680 fs/splice.c:1049
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1230
 do_sendfile+0x380/0x650 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1417
 x64_sys_call+0x2bb4/0x3000 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff88e71d30 of 8 bytes by task 8111 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:591 [inline]
 data_push_tail+0xfd/0x420 kernel/printk/printk_ringbuffer.c:676
 data_alloc+0xfb/0x2e0 kernel/printk/printk_ringbuffer.c:1061
 prb_reserve+0x807/0xaf0 kernel/printk/printk_ringbuffer.c:1685
 vprintk_store+0x56d/0x860 kernel/printk/printk.c:2299
 vprintk_emit+0x10d/0x580 kernel/printk/printk.c:2399
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2438
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2448
 __ext4_error+0x248/0x320 fs/ext4/super.c:822
 ext4_free_blocks+0x124f/0x1480 fs/ext4/mballoc.c:-1
 ext4_remove_blocks fs/ext4/extents.c:2533 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2716 [inline]
 ext4_ext_remove_space+0x194e/0x2900 fs/ext4/extents.c:2965
 ext4_ext_truncate+0xc7/0x170 fs/ext4/extents.c:4484
 ext4_truncate+0x70d/0xae0 fs/ext4/inode.c:4614
 ext4_evict_inode+0x8a7/0xd90 fs/ext4/inode.c:261
 evict+0x2e3/0x550 fs/inode.c:810
 iput_final fs/inode.c:1914 [inline]
 iput+0x4ed/0x650 fs/inode.c:1966
 ext4_process_orphan+0x1a9/0x1c0 fs/ext4/orphan.c:356
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x3483/0x3810 fs/ext4/super.c:5736
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1698
 get_tree_bdev+0x1f/0x30 fs/super.c:1721
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5768
 vfs_get_tree+0x57/0x1d0 fs/super.c:1758
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3642 [inline]
 do_new_mount+0x24d/0x660 fs/namespace.c:3718
 path_mount+0x4a5/0xb70 fs/namespace.c:4028
 do_mount fs/namespace.c:4041 [inline]
 __do_sys_mount fs/namespace.c:4229 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4206
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4206
 x64_sys_call+0x2b51/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000ffffe7ba -> 0x70202c31206c6176

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8111 Comm: syz.1.1602 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
==================================================================
EXT4-fs error (device loop1): ext4_read_inode_bitmap:139: comm syz.1.1602: Invalid inode bitmap blk 0 in block_group 0
EXT4-fs error (device loop1) in ext4_free_inode:361: Corrupt filesystem
EXT4-fs (loop1): 1 orphan inode deleted
EXT4-fs (loop1): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
lo speed is unknown, defaulting to 1000

Crashes (152):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/22 02:41 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/21 14:58 upstream fd95357fd8c6 280ea308 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/20 00:35 upstream 23cb64fb7625 26ee5237 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/18 10:58 upstream e7c375b18160 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/16 20:21 upstream 7254a2b52279 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/16 15:15 upstream f824272b6e3f f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/15 14:21 upstream 7a0892d2836e f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/14 21:02 upstream d4f8cccc6230 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/13 20:12 upstream 2ccec5944606 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/13 14:04 upstream e927c520e1ba 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/12 19:34 upstream 24172e0d7990 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/12 00:16 upstream 24172e0d7990 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/10 05:09 upstream e9a6fb0bcdd7 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/09 06:07 upstream 7bb4d6512545 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/08 16:39 upstream e811c33b1f13 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/07 14:08 upstream 4a0c9b339199 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/06 03:34 upstream 1c353dc8d962 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/05 04:20 upstream 17d85f33a83b 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/05 01:01 upstream c9cfc122f037 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/02 17:01 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/11/01 11:29 upstream ba36dd5ee6fd 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/31 20:03 upstream 58fdd8484c05 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/30 07:03 upstream e53642b87a4f fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/28 02:09 upstream fd57572253bc fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/27 16:28 upstream dcb6fa37fd7b fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/26 19:35 upstream dbfc6422a34d c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/25 02:38 upstream d2818517e348 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/22 10:18 upstream 552c50713f27 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/17 18:32 upstream cf1ea8854e4f 7adf5298 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/15 15:26 upstream 9b332cece987 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/13 11:54 upstream 3a8660878839 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/12 19:24 upstream 8765f467912f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/10 05:19 upstream 5472d60c129f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/09 22:02 upstream ec714e371f22 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/08 13:37 upstream 0d97f2067c16 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/08 09:52 upstream 971199ad2a0f 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/05 01:02 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/04 15:33 upstream cbf33b8e0b36 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/04 00:05 upstream 9b0d551bcc05 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/10/02 02:17 upstream 080ffb4bec4d 267f56c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/09/29 01:03 upstream 8f9736633f8c 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/09/27 13:39 upstream fec734e8d564 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / vsnprintf
2025/09/26 05:55 upstream 4ff71af020ae 0abd0691 .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.