[syzbot] [trace?] WARNING in tracing_buffers_mmap_close (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4a0c9b339199 Merge tag 'probes-fixes-v6.18-rc4' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=127c3bcd980000
kernel config: https://syzkaller.appspot.com/x/.config?x=19d831c6d0386a9c
dashboard link: https://syzkaller.appspot.com/bug?extid=a72c325b042aae6403c7
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13fb5342580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167c3bcd980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0885fd14dc45/disk-4a0c9b33.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d090edb8df65/vmlinux-4a0c9b33.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fe620e34d128/bzImage-4a0c9b33.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a72c32...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5989 at kernel/trace/trace.c:8780 tracing_buffers_mmap_close kernel/trace/trace.c:8780 [inline]
WARNING: CPU: 0 PID: 5989 at kernel/trace/trace.c:8780 tracing_buffers_mmap_close+0xdd/0x130 kernel/trace/trace.c:8775
Modules linked in:
CPU: 0 UID: 0 PID: 5989 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:tracing_buffers_mmap_close kernel/trace/trace.c:8780 [inline]
RIP: 0010:tracing_buffers_mmap_close+0xdd/0x130 kernel/trace/trace.c:8775
Code: 75 46 48 8b 7b 08 e8 b2 94 ff ff 31 ff 89 c3 89 c6 e8 07 4b fb ff 85 db 75 0a 48 83 c4 08 5b e9 b9 4f fb ff e8 b4 4f fb ff 90 <0f> 0b 90 48 83 c4 08 5b e9 a6 4f fb ff e8 b1 e6 62 00 eb 87 e8 da
RSP: 0018:ffffc90003047ba8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000ffffffed RCX: ffffffff81c11d89
RDX: ffff888020713c80 RSI: ffffffff81c11d9c RDI: 0000000000000005
RBP: ffffffff81c11cc0 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffed R11: 0000000000000000 R12: ffff8880217512c8
R13: dffffc0000000000 R14: ffffc90003047c30 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555606ff808 CR3: 000000000e182000 CR4: 00000000003526f0
Call Trace:
<TASK>
vma_close mm/internal.h:190 [inline]
remove_vma+0x88/0x160 mm/vma.c:464
exit_mmap+0x50a/0xb90 mm/mmap.c:1305
__mmput+0x12a/0x410 kernel/fork.c:1133
mmput+0x62/0x70 kernel/fork.c:1156
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:954
do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1116
x64_sys_call+0x150b/0x1730 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f168a18f6c9
Code: Unable to access opcode bytes at 0x7f168a18f69f.
RSP: 002b:00007ffff8c604f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f168a18f6c9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00000004f8c605ef R09: 00007f168a3b1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f168a3b1280 R14: 0000000000000003 R15: 00007ffff8c605b0
</TASK>


---
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[Hillf Danton]

> Date: Tue, 11 Nov 2025 09:05:31 -0800

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 4a0c9b339199 Merge tag 'probes-fixes-v6.18-rc4' of git://g..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=127c3bcd980000
> kernel config: https://syzkaller.appspot.com/x/.config?x=19d831c6d0386a9c
> dashboard link: https://syzkaller.appspot.com/bug?extid=a72c325b042aae6403c7
> compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13fb5342580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=167c3bcd980000

#syz test

--- x/mm/mmap_lock.c
+++ y/mm/mmap_lock.c
@@ -240,6 +240,7 @@ retry:
/* Check if the VMA got isolated after we found it */
if (PTR_ERR(vma) == -EAGAIN) {
count_vm_vma_lock_event(VMA_LOCK_MISS);
+ mas_set(&mas, address);
/* The area was replaced with another one */
goto retry;
}
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in tracing_buffers_mmap_close

------------[ cut here ]------------
WARNING: CPU: 0 PID: 6465 at kernel/trace/trace.c:8780 tracing_buffers_mmap_close kernel/trace/trace.c:8780 [inline]
WARNING: CPU: 0 PID: 6465 at kernel/trace/trace.c:8780 tracing_buffers_mmap_close+0xdd/0x130 kernel/trace/trace.c:8775
Modules linked in:
CPU: 0 UID: 0 PID: 6465 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025

RIP: 0010:tracing_buffers_mmap_close kernel/trace/trace.c:8780 [inline]
RIP: 0010:tracing_buffers_mmap_close+0xdd/0x130 kernel/trace/trace.c:8775

Code: 75 46 48 8b 7b 08 e8 92 94 ff ff 31 ff 89 c3 89 c6 e8 e7 4a fb ff 85 db 75 0a 48 83 c4 08 5b e9 99 4f fb ff e8 94 4f fb ff 90 <0f> 0b 90 48 83 c4 08 5b e9 86 4f fb ff e8 51 f9 62 00 eb 87 e8 7a
RSP: 0018:ffffc900033a7980 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000ffffffed RCX: ffffffff81c108d9
RDX: ffff88802f3b0000 RSI: ffffffff81c108ec RDI: 0000000000000005
RBP: ffffffff81c10810 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000ffffffed R11: 0000000000000000 R12: ffff888046203408
R13: dffffc0000000000 R14: ffffc900033a7a08 R15: 0000000000000000

FS: 0000000000000000(0000) GS:ffff888124a0d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f36505f5f98 CR3: 000000000e182000 CR4: 00000000003526f0

Call Trace:
<TASK>
vma_close mm/internal.h:190 [inline]
remove_vma+0x88/0x160 mm/vma.c:464
exit_mmap+0x50a/0xb90 mm/mmap.c:1305
__mmput+0x12a/0x410 kernel/fork.c:1133
mmput+0x62/0x70 kernel/fork.c:1156
exit_mm kernel/exit.c:582 [inline]
do_exit+0x7c7/0x2bf0 kernel/exit.c:954
do_group_exit+0xd3/0x2a0 kernel/exit.c:1107

get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3650f8f6c9
Code: Unable to access opcode bytes at 0x7f3650f8f69f.
RSP: 002b:00007f36505f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f36511e5fa8 RCX: 00007f3650f8f6c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f36511e5fa8
RBP: 00007f36511e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36511e6038 R14: 00007ffdf110f910 R15: 00007ffdf110f9f8
</TASK>


Tested on:

commit: 24172e0d Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13370212580000

kernel config: https://syzkaller.appspot.com/x/.config?x=19d831c6d0386a9c
dashboard link: https://syzkaller.appspot.com/bug?extid=a72c325b042aae6403c7
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=135b560a580000