syzbot


KCSAN: data-race in desc_read_finalized_seq / prb_reserve

Status: moderation: reported on 2025/02/14 06:35
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+383a92f48ff01d88d395@syzkaller.appspotmail.com
First crash: 30d, last: 1d09h

Sample crash report:
==================================================================
BUG: KCSAN: data-race in desc_read_finalized_seq / prb_reserve

write to 0xffffffff866db788 of 8 bytes by task 2928 on cpu 1:
 prb_reserve+0x740/0xb60
 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326
 vprintk_emit+0x168/0x690 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 set_capacity_and_notify+0x151/0x200 block/genhd.c:93
 loop_set_size+0x2e/0x70 drivers/block/loop.c:234
 loop_configure+0x8bd/0xa50 drivers/block/loop.c:1106
 lo_ioctl+0x613/0x14f0
 blkdev_ioctl+0x359/0x450 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xc9/0x140 fs/ioctl.c:892
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:892
 x64_sys_call+0x1690/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff866db788 of 8 bytes by task 2930 on cpu 0:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 desc_read_finalized_seq+0x157/0x280 kernel/printk/printk_ringbuffer.c:1874
 prb_read kernel/printk/printk_ringbuffer.c:1922 [inline]
 _prb_read_valid+0x140/0x6c0 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 __console_flush_and_unlock kernel/printk/printk.c:3288 [inline]
 console_unlock+0x180/0x340 kernel/printk/printk.c:3309
 do_con_write+0x2582/0x25f0
 con_write+0x26/0x40 drivers/tty/vt/vt.c:3432
 process_output_block drivers/tty/n_tty.c:574 [inline]
 n_tty_write+0x843/0xb80 drivers/tty/n_tty.c:2389
 iterate_tty_write drivers/tty/tty_io.c:1015 [inline]
 file_tty_write+0x37a/0x680 drivers/tty/tty_io.c:1090
 tty_write+0x28/0x30 drivers/tty/tty_io.c:1111
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77b/0x920 fs/read_write.c:679
 ksys_write+0xe8/0x1b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:739
 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000004cbd -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2930 Comm: syz.6.11231 Tainted: G        W          6.14.0-rc6-syzkaller-00202-ga29967be967e #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
netlink: 'syz.6.11231': attribute type 13 has an invalid length.

Crashes (35):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/15 07:42 upstream a29967be967e e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/13 11:07 upstream b7f94fcf5546 44be8b44 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/12 17:51 upstream 0fed89a961ea ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/12 07:54 upstream 0b46b049d6ec ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/08 07:29 upstream 21e4543a2e2f 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/07 16:16 upstream 00a7d39898c8 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/06 13:52 upstream 848e07631744 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/05 11:35 upstream 48a5eed9ad58 60f5d8d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/03 17:09 upstream 7eb172143d55 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/02 23:37 upstream b91872c56940 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/02 07:41 upstream ece144f151ac c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/02 07:29 upstream ece144f151ac c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/01 19:34 upstream 03d38806a902 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/03/01 06:06 upstream 7a5668899f54 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/28 23:42 upstream 76544811c850 67cf5345 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/28 05:16 upstream 1e15510b71c9 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/27 16:27 upstream dd83757f6e68 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/27 00:43 upstream 5394eea10651 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/25 20:32 upstream 2a1944bff549 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/24 03:27 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/23 20:39 upstream 27102b38b8ca d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/23 01:42 upstream 5cf80612d3f7 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/21 23:12 upstream 8a61cb6e150e d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/21 11:57 upstream 334426094588 0808a665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/21 02:49 upstream e9a8cac0bf89 0808a665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/20 11:34 upstream 87a132e73910 50668798 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/19 17:54 upstream 6537cfb395f3 b257a9b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/19 01:35 upstream 6537cfb395f3 9a14138f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/18 04:36 upstream 2408a807bfc3 429ea007 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/17 01:35 upstream 224e74511041 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/16 14:32 upstream ad1b832bf1cf 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/15 20:44 upstream 496659003dac 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/14 17:30 upstream 128c8f96eb86 1022af74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/14 06:39 upstream 68763b29e0a6 d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
2025/02/14 06:34 upstream 68763b29e0a6 d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in desc_read_finalized_seq / prb_reserve
* Struck through repros no longer work on HEAD.