syzbot


KCSAN: data-race in data_push_tail / uuid_string (2)

Status: auto-obsoleted due to no activity on 2024/01/09 18:19
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+36f772d61eb67698ca62@syzkaller.appspotmail.com
First crash: 199d, last: 199d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in data_push_tail / uuid_string (3) ext4 1 61d 61d 0/27 auto-obsoleted due to no activity on 2024/05/24 03:21
upstream KCSAN: data-race in data_push_tail / uuid_string ext4 4 270d 348d 0/27 auto-obsoleted due to no activity on 2023/10/28 05:07

Sample crash report:
EXT4-fs (loop0): orphan cleanup on readonly fs
EXT4-fs error (device loop0): ext4_xattr_ibody_find:2263: inode #15: comm syz-executor.0: corrupted in-inode xattr: bad e_name length
==================================================================
BUG: KCSAN: data-race in data_push_tail / uuid_string

write to 0xffffffff86eb2536 of 1 bytes by task 26075 on cpu 1:
 string_nocheck lib/vsprintf.c:650 [inline]
 uuid_string+0x435/0x4b0 lib/vsprintf.c:1731
 pointer+0x3ee/0xd10 lib/vsprintf.c:2448
 vsnprintf+0x861/0xe20 lib/vsprintf.c:2823
 va_format lib/vsprintf.c:1683 [inline]
 pointer+0x8a1/0xd10 lib/vsprintf.c:2450
 vsnprintf+0x861/0xe20 lib/vsprintf.c:2823
 vscnprintf+0x42/0x80 lib/vsprintf.c:2925
 printk_sprint+0x30/0x2d0 kernel/printk/printk.c:2124
 vprintk_store+0x56f/0x800 kernel/printk/printk.c:2238
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 __ext4_msg+0x18a/0x1a0 fs/ext4/super.c:1006
 ext4_fill_super+0x1a1f/0x39a0 fs/ext4/super.c:5727
 get_tree_bdev+0x272/0x300 fs/super.c:1598
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5744
 vfs_get_tree+0x51/0x1b0 fs/super.c:1771
 do_new_mount+0x203/0x660 fs/namespace.c:3337
 path_mount+0x496/0xb30 fs/namespace.c:3664
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffffffff86eb2530 of 8 bytes by task 26072 on cpu 0:
 data_make_reusable kernel/printk/printk_ringbuffer.c:590 [inline]
 data_push_tail+0x102/0x430 kernel/printk/printk_ringbuffer.c:675
 data_alloc+0xbe/0x2c0 kernel/printk/printk_ringbuffer.c:1046
 prb_reserve+0x893/0xbc0 kernel/printk/printk_ringbuffer.c:1555
 vprintk_store+0x53e/0x800 kernel/printk/printk.c:2228
 vprintk_emit+0xd0/0x5d0 kernel/printk/printk.c:2284
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2318
 vprintk+0x71/0x80 kernel/printk/printk_safe.c:45
 _printk+0x7a/0xa0 kernel/printk/printk.c:2328
 __ext4_error_inode+0x2d5/0x400 fs/ext4/super.c:869
 check_xattrs+0x6ba/0x770 fs/ext4/xattr.c:294
 __xattr_check_inode fs/ext4/xattr.c:315 [inline]
 ext4_xattr_ibody_find+0x1a6/0x390 fs/ext4/xattr.c:2263
 ext4_find_inline_data_nolock+0xb9/0x1f0 fs/ext4/inline.c:157
 ext4_iget_extra_inode+0xdf/0x1a0 fs/ext4/inode.c:4630
 __ext4_iget+0x12de/0x1e90 fs/ext4/inode.c:4897
 ext4_orphan_get+0x140/0x3e0 fs/ext4/ialloc.c:1394
 ext4_orphan_cleanup+0x5bc/0x9b0 fs/ext4/orphan.c:467
 __ext4_fill_super fs/ext4/super.c:5591 [inline]
 ext4_fill_super+0x3660/0x39a0 fs/ext4/super.c:5712
 get_tree_bdev+0x272/0x300 fs/super.c:1598
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5744
 vfs_get_tree+0x51/0x1b0 fs/super.c:1771
 do_new_mount+0x203/0x660 fs/namespace.c:3337
 path_mount+0x496/0xb30 fs/namespace.c:3664
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3863
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000fffffe83 -> 0x30303030206d6574

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26072 Comm: syz-executor.0 Not tainted 6.7.0-rc3-syzkaller-00298-g1b8af6552cb7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================
EXT4-fs error (device loop0): ext4_orphan_get:1399: comm syz-executor.0: couldn't read orphan inode 15 (err -117)
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 ro without journal. Quota mode: writeback.
EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/03 08:33 upstream 1b8af6552cb7 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in data_push_tail / uuid_string
* Struck through repros no longer work on HEAD.