[syzbot] [jfs?] [nilfs?] WARNING in mnt_ns_release

syzbot
2024-12-24T04:48:28Z

Hello,

syzbot found the following issue on:

HEAD commit: 8503810115fb Add linux-next specific files for 20241219
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14412fe8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=26a4b4cc7f877b28
dashboard link: https://syzkaller.appspot.com/bug?extid=5b9d613904b2f185f2fe
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134992df980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8e84022cbe98/disk-85038101.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/112a23063d67/vmlinux-85038101.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3778558f0562/bzImage-85038101.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/3e0de479e20d/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/051056cfbd12/mount_1.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5b9d613904b2f185f2fe@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5847 at fs/namespace.c:163 mnt_ns_release+0x15d/0x1c0 fs/namespace.c:163
Modules linked in:
CPU: 0 UID: 0 PID: 5847 Comm: syz-executor Not tainted 6.13.0-rc3-next-20241219-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
RIP: 0010:mnt_ns_release+0x15d/0x1c0 fs/namespace.c:163
Code: 15 bf 01 00 00 00 89 ee e8 90 fc 7d ff 85 ed 7e 39 e8 47 f8 7d ff 4c 89 ff 5b 41 5e 41 5f 5d e9 19 ca d8 ff e8 34 f8 7d ff 90 <0f> 0b 90 e9 12 ff ff ff e8 26 f8 7d ff 48 89 df be 03 00 00 00 5b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010246
RAX: ffffffff8241281c RBX: 0000000000000001 RCX: ffff888034a81e00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90000007e10 R08: ffffffff82412722 R09: 1ffffffff285ab0b
R10: dffffc0000000000 R11: ffffffff82422da0 R12: ffffffff81a6a587
R13: ffff88807cec0e58 R14: dffffc0000000000 R15: ffff88807cec0e00
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f98aaffed00 CR3: 0000000076918000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
rcu_do_batch kernel/rcu/tree.c:2546 [inline]
rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2802
handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
__do_softirq kernel/softirq.c:595 [inline]
invoke_softirq kernel/softirq.c:435 [inline]
__irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662
irq_exit_rcu+0x9/0x30 kernel/softirq.c:678
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:228 [inline]
RIP: 0010:rb_erase+0x3e/0xe70 lib/rbtree.c:443
Code: 74 24 20 48 89 fb 48 b9 00 00 00 00 00 fc ff df 48 83 c7 08 48 89 f8 48 c1 e8 03 80 3c 08 00 74 05 e8 56 08 39 f6 4c 8b 63 08 <4c> 8d 7b 10 4d 89 fd 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df 41
RSP: 0018:ffffc9000414f9f8 EFLAGS: 00000246
RAX: 1ffff11005f7cf97 RBX: ffff88802fbe7cb0 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: ffffffff9a4501a0 RDI: ffff88802fbe7cb8
RBP: 1ffff11005f7cf89 R08: ffffffff942d5857 R09: 1ffffffff285ab0a
R10: dffffc0000000000 R11: fffffbfff285ab0b R12: 0000000000000000
R13: dffffc0000000000 R14: ffffffff818b397d R15: ffff88802fbe7c00
mnt_ns_tree_remove fs/namespace.c:183 [inline]
free_mnt_ns+0x10f/0x210 fs/namespace.c:3916
free_nsproxy+0x4d/0x3c0 kernel/nsproxy.c:193
do_exit+0xa2a/0x28e0 kernel/exit.c:937
do_group_exit+0x207/0x2c0 kernel/exit.c:1087
get_signal+0x16b2/0x1750 kernel/signal.c:3017
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbe62f846fd
Code: Unable to access opcode bytes at 0x7fbe62f846d3.
RSP: 002b:00007ffeb8ef6dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 00007fbe62f846fd
RDX: 0000000000000030 RSI: 00007ffeb8ef6e50 RDI: 00000000000000f9
RBP: 00007ffeb8ef6dfc R08: 00000000000003b8 R09: 0079746972756365
R10: 00007fbe631487e0 R11: 0000000000000246 R12: 00007fbe63145f68
R13: 000000000001946d R14: 00007ffeb8ef6e50 R15: 0000000000000001
</TASK>
----------------
Code disassembly (best guess):
0: 74 24 je 0x26
2: 20 48 89 and %cl,-0x77(%rax)
5: fb sti
6: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
d: fc ff df
10: 48 83 c7 08 add $0x8,%rdi
14: 48 89 f8 mov %rdi,%rax
17: 48 c1 e8 03 shr $0x3,%rax
1b: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
1f: 74 05 je 0x26
21: e8 56 08 39 f6 call 0xf639087c
26: 4c 8b 63 08 mov 0x8(%rbx),%r12
* 2a: 4c 8d 7b 10 lea 0x10(%rbx),%r15 <-- trapping instruction
2e: 4d 89 fd mov %r15,%r13
31: 49 c1 ed 03 shr $0x3,%r13
35: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
3c: fc ff df
3f: 41 rex.B

---
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