Re: WARNING in __kthread_create_on_node

[Andrew Morton <akpm@linux-foundation.org>]

(cc linux-ext4)

Interesting.

On Thu, 14 Mar 2024 22:23:54 +0800 cheung wall <zzqq0103.hey@gmail.com> wrote:

> Hello,
> 
> when using Healer to fuzz the latest Linux Kernel, the following crash
> 
> was triggered on:
> 
> 
> HEAD commit: e8f897f4afef0031fe618a8e94127a0934896aba  (tag: v6.8)
> 
> git tree: upstream
> 
> console output: https://pastebin.com/raw/4dqjbmVn
> 
> kernel config: https://pastebin.com/raw/enVJCL3u
> 
> C reproducer: https://pastebin.com/raw/wdKP6g0V
> 
> Syzlang reproducer: https://pastebin.com/raw/wfptradq
> 
> If you fix this issue, please add the following tag to the commit:
> 
> Reported-by: Qiang Zhang <zzqq0103.hey@gmail.com>
> 
> ----------------------------------------------------------
> 
> ------------[ cut here ]------------
> different return values (11 and 6) from vsnprintf("kmmpd-%.*s", ...)
> WARNING: CPU: 0 PID: 18743 at lib/kasprintf.c:30
> kvasprintf+0x14e/0x160 lib/kasprintf.c:30
> Modules linked in:
> CPU: 0 PID: 18743 Comm: syz-executor.0 Not tainted 6.8.0 #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:kvasprintf+0x14e/0x160 lib/kasprintf.c:30
> Code: 5b 5d 41 5c 41 5d 41 5e 41 5f e9 e8 2f 2d 02 e8 08 54 43 ff 90
> 48 c7 c7 40 62 fe a1 4c 89 e9 44 89 e2 89 ee e8 d3 62 13 ff 90 <0f> 0b
> 90 90 eb 99 e8 27 96 12 02 0f 1f 80 00 00 00 00 90 90 90 90
> RSP: 0018:ffff88810485f760 EFLAGS: 00010286
> RAX: 0000000000000000 RBX: 1ffff1102090beec RCX: ffffffff9eb67582
> RDX: ffff888104dfe600 RSI: 0000000000000000 RDI: 0000000000000001
> RBP: 000000000000000b R08: 0000000000000001 R09: ffffed10235c5121
> R10: 0000000000000000 R11: 000000002d2d2d2d R12: 0000000000000006
> R13: ffffffffa1f42a20 R14: ffff888100b62900 R15: 000000000000000c
> FS:  00007f8db8f7e640(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
> loop2: detected capacity change from 0 to 512
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007ffcd493ab98 CR3: 00000001063fe004 CR4: 0000000000770ef0
> PKRU: 55555554
> Call Trace:
>  <TASK>
> loop3: detected capacity change from 0 to 512
>  __kthread_create_on_node+0x17f/0x3c0 kernel/kthread.c:444
>  kthread_create_on_node+0xbf/0x100 kernel/kthread.c:512
> loop1: detected capacity change from 0 to 512
>  ext4_multi_mount_protect+0x953/0xb10 fs/ext4/mmp.c:392
>  __ext4_fill_super fs/ext4/super.c:5363 [inline]
>  ext4_fill_super+0xa76d/0xc290 fs/ext4/super.c:5703
>  get_tree_bdev+0x35a/0x5d0 fs/super.c:1614
>  vfs_get_tree+0x8c/0x320 fs/super.c:1779
>  do_new_mount fs/namespace.c:3352 [inline]
>  path_mount+0x6b3/0x1db0 fs/namespace.c:3679
>  do_mount fs/namespace.c:3692 [inline]
>  __do_sys_mount fs/namespace.c:3898 [inline]
>  __se_sys_mount fs/namespace.c:3875 [inline]
>  __x64_sys_mount+0x286/0x310 fs/namespace.c:3875
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xb3/0x1b0 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x6f/0x77
> RIP: 0033:0x7f8db9410dfe
> Code: 48 c7 c0 ff ff ff ff eb aa e8 be 0d 00 00 66 2e 0f 1f 84 00 00
> 00 00 00 0f 1f 40 00 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d
> 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007f8db8f7de38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 00000000000004b4 RCX: 00007f8db9410dfe
> RDX: 0000000020000040 RSI: 0000000020000500 RDI: 00007f8db8f7de90
> RBP: 00007f8db8f7ded0 R08: 00007f8db8f7ded0 R09: 0000000000004500
> R10: 0000000000004500 R11: 0000000000000246 R12: 0000000020000040
> R13: 0000000020000500 R14: 00007f8db8f7de90 R15: 0000000020000540
>  </TASK>
> ---[ end trace 0000000000000000 ]---