syzbot


KCSAN: data-race in console_flush_all / console_flush_all

Status: moderation: reported on 2024/09/24 07:21
Subsystems: isofs
[Documentation on labels]
Reported-by: syzbot+e1863428fbecbb36ac13@syzkaller.appspotmail.com
First crash: 524d, last: 1d00h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
aa83c0ab-53ae-42ea-93d5-7099f37916dd assessment-kcsan Benign: ❌  KCSAN: data-race in console_flush_all / console_flush_all 2026/01/12 17:15 2026/01/12 17:15 2026/01/12 17:38 dc57dbf3ee402bd8ad9c3037d56ee9d9940a9bc6

Sample crash report:
EXT4-fs error (device loop4) in ext4_orphan_del:303: Corrupt filesystem
loop4: lost filesystem error report for type 5 error -117
EXT4-fs error (device loop4): ext4_do_update_inode:5569: inode #16: comm syz.4.7412: corrupted inode contents
==================================================================
BUG: KCSAN: data-race in console_flush_all / console_flush_all

write to 0xffffffff86e3cda8 of 8 bytes by task 32497 on cpu 0:
 console_emit_next_record kernel/printk/printk.c:3188 [inline]
 console_flush_one_record kernel/printk/printk.c:3269 [inline]
 console_flush_all+0x45f/0x6c0 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xa1/0x280 kernel/printk/printk.c:3413
 vprintk_emit+0x3e4/0x600 kernel/printk/printk.c:2479
 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
 __ext4_std_error+0x31d/0x350 fs/ext4/super.c:969
 ext4_orphan_del+0x689/0x710 fs/ext4/orphan.c:303
 ext4_truncate+0x89c/0xb00 fs/ext4/inode.c:4584
 ext4_process_orphan+0x110/0x1c0 fs/ext4/orphan.c:337
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5668 [inline]
 ext4_fill_super+0x3408/0x37c0 fs/ext4/super.c:5791
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5823
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3839
 path_mount+0x4d0/0xbc0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4338
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4338
 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/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86e3cda8 of 8 bytes by task 32504 on cpu 1:
 console_flush_one_record kernel/printk/printk.c:3270 [inline]
 console_flush_all+0x548/0x6c0 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xa1/0x280 kernel/printk/printk.c:3413
 vprintk_emit+0x3e4/0x600 kernel/printk/printk.c:2479
 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
 __ext4_error_inode+0x2af/0x3f0 fs/ext4/super.c:855
 ext4_do_update_inode fs/ext4/inode.c:5569 [inline]
 ext4_mark_iloc_dirty+0x35d/0xdb0 fs/ext4/inode.c:6215
 __ext4_mark_inode_dirty+0x2e0/0x400 fs/ext4/inode.c:6421
 ext4_truncate+0x8e2/0xb00 fs/ext4/inode.c:4587
 ext4_process_orphan+0x110/0x1c0 fs/ext4/orphan.c:337
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:472
 __ext4_fill_super fs/ext4/super.c:5668 [inline]
 ext4_fill_super+0x3408/0x37c0 fs/ext4/super.c:5791
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5823
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3839
 path_mount+0x4d0/0xbc0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4338
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4338
 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/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000003fd5 -> 0x0000000000003fd6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 32504 Comm: syz.4.7412 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================
EXT4-fs error (device loop4): ext4_truncate:4587: inode #16: comm syz.4.7412: mark_inode_dirty error
EXT4-fs error (device loop4) in ext4_process_orphan:345: Corrupt filesystem
loop4: lost filesystem error report for type 5 error -117
EXT4-fs (loop4): 1 truncate cleaned up
EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: writeback.

Crashes (90):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/01 12:27 upstream eb71ab2bf722 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/02/04 04:08 upstream de0674d9bc69 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/01/12 10:31 upstream 9c7ef209cd0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/01/10 10:36 upstream b6151c4e60e5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/01/05 13:34 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/01/03 12:48 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2026/01/01 22:33 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/12/20 12:07 upstream dd9b004b7ff3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/12/07 00:26 upstream cc3ee4ba57b7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/11/16 02:50 upstream f824272b6e3f f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/11/02 04:35 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/10/31 16:19 upstream d127176862a9 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/10/21 03:46 upstream 6548d364a3e8 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/10/16 03:04 upstream 1f4a222b0e33 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/10/01 00:34 upstream 30d4efb2f5a5 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/29 05:45 upstream 8f9736633f8c 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/28 05:05 upstream 51a24b7deaae 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/26 00:28 upstream 4ff71af020ae 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/21 11:54 upstream f975f08c2e89 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/18 01:47 upstream d4b779985a6c e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/16 03:31 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/09 23:06 upstream 9dd1835ecda5 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/09/05 08:33 upstream d69eb204c255 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/31 22:24 upstream 5c3b3264e585 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/16 12:53 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/11 09:46 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/05 16:13 upstream 7e161a991ea7 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/05 05:30 upstream d632ab86aff2 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/02 14:04 upstream a6923c06a3b2 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/02 01:08 upstream 0905809b38bd 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/08/01 08:13 upstream f2d282e1dfb3 0c075d67 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/30 18:54 upstream 4b290aae788e f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/25 03:17 upstream 94ce1ac2c9b4 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/18 17:48 upstream 6832a9317eee 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/10 13:28 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/09 23:24 upstream 8c2e52ebbe88 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/05 17:55 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/07/04 09:34 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/06/23 03:06 upstream b67ec639010f d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/06/22 12:54 upstream 739a6c93cc75 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/06/20 00:37 upstream 24770983ccfe ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/28 22:39 upstream 3d413f0cfd7e 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/18 14:24 upstream 5723cc3450bc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/16 05:38 upstream fee3e843b309 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/16 00:53 upstream 088d13246a46 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/10 23:34 upstream bec6f00f120e 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/09 09:14 upstream 2c89c1b655c0 bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/03 01:08 upstream 2bfcee565c3a b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/05/01 21:26 upstream 4f79eaa2ceac 51b137cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/04/24 23:40 upstream e72e9e693307 9882047a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/04/10 05:34 upstream 3b07108ada81 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2025/01/05 08:19 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/27 19:23 upstream d6ef8b40d075 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/26 10:19 upstream 9b2ffa6148b1 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/24 19:36 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/10 11:56 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/08 22:10 upstream 62b5a46999c7 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/08 06:16 upstream 7503345ac5f5 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/05 23:36 upstream 5076001689e4 29f61fce .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/05 13:09 upstream feffde684ac2 29f61fce .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/03 00:27 upstream e70140ba0d2b b499ea68 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/12/01 09:57 upstream bcc8eda6d349 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/11/27 17:21 upstream aaf20f870da0 52b38cc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/11/21 21:35 upstream 43fb83c17ba2 4b25d554 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/11/09 15:33 upstream da4373fbcf00 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/11/06 08:51 upstream 2e1b3cc9d7f7 3a465482 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/10/30 01:59 upstream e42b1a9a2557 66aeb999 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/10/18 16:51 upstream 4d939780b705 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/10/11 00:49 upstream eb952c47d154 8fbfc0c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
2024/09/24 07:20 upstream 18ba6034468e 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in console_flush_all / console_flush_all
* Struck through repros no longer work on HEAD.