[syzbot] [net?] [usb?] kernel BUG in dql_completed

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: d358e5254674 Merge tag 'for-6.19/dm-changes' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1191799c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b60f8d9470fe9d28
dashboard link: https://syzkaller.appspot.com/bug?extid=5b55e49f8bbd84631a9c
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
userspace arch: i386

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6023f764316a/disk-d358e525.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7d83b86d067e/vmlinux-d358e525.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7fa17a04a4c5/bzImage-d358e525.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5b55e4...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at lib/dynamic_queue_limits.c:99!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5197 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:dql_completed+0xbe1/0xbf0 lib/dynamic_queue_limits.c:99
Code: 93 61 fd e9 ae fc ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c c2 fc ff ff 48 89 df e8 8a 92 61 fd e9 b5 fc ff ff e8 d0 40 fb fc 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a08a70 EFLAGS: 00010246
RAX: ffffffff84c66fe0 RBX: 00000000000000f1 RCX: ffff88807df58000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 00000000000000f1
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141154 R12: 1ffff1100fc56520
R13: 1ffff1100fc56519 R14: ffff88807e2b2904 R15: ffff88807e2b28c0
FS: 00007fdf0904e880(0000) GS:ffff888125f3a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000080159018 CR3: 000000007e786000 CR4: 00000000003526f0
Call Trace:
<IRQ>
netdev_tx_completed_queue include/linux/netdevice.h:3864 [inline]
netdev_completed_queue include/linux/netdevice.h:3894 [inline]
usbnet_bh+0x793/0x1020 drivers/net/usb/usbnet.c:1601
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
bh_worker+0x2b1/0x600 kernel/workqueue.c:3611
tasklet_action+0xc/0x70 kernel/softirq.c:952
handle_softirqs+0x27d/0x850 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:mas_wr_append lib/maple_tree.c:3718 [inline]
RIP: 0010:mas_wr_store_entry+0xe25/0x27b0 lib/maple_tree.c:3758
Code: 24 40 48 8b 4c 24 48 48 8d 1c c1 48 89 d8 48 c1 e8 03 42 80 3c 28 00 44 0f b6 7c 24 1c 74 08 48 89 df e8 3e 39 d5 f6 4c 89 33 <49> 8d 5c 24 48 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df
RSP: 0018:ffffc90003106fe0 EFLAGS: 00000246
RAX: ffffc900031077cd RBX: 1ffff92000620ebd RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000008
RBP: ffffc90003107570 R08: ffff88807df58000 R09: 000000000000000a
R10: 0000000000000009 R11: 0000000000000000 R12: ffffc900031075c0
R13: dffffc0000000000 R14: ffff88807e776640 R15: 0000000000000009
mas_insert+0x375/0x550 lib/maple_tree.c:4002
mas_alloc_cyclic+0x207/0x700 lib/maple_tree.c:4048
mtree_alloc_cyclic+0x181/0x220 lib/maple_tree.c:6092
simple_offset_add+0xdc/0x190 fs/libfs.c:297
shmem_mknod+0x232/0x360 mm/shmem.c:3884
lookup_open fs/namei.c:4440 [inline]
open_last_lookups fs/namei.c:4540 [inline]
path_openat+0x18bb/0x3dd0 fs/namei.c:4784
do_filp_open+0x1fa/0x410 fs/namei.c:4814
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdf088a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff05e7f490 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fdf0904e880 RCX: 00007fdf088a7407
RDX: 0000000000080141 RSI: 000055fcaafb702e RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff
R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dql_completed+0xbe1/0xbf0 lib/dynamic_queue_limits.c:99
Code: 93 61 fd e9 ae fc ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c c2 fc ff ff 48 89 df e8 8a 92 61 fd e9 b5 fc ff ff e8 d0 40 fb fc 90 <0f> 0b 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
RSP: 0018:ffffc90000a08a70 EFLAGS: 00010246
RAX: ffffffff84c66fe0 RBX: 00000000000000f1 RCX: ffff88807df58000
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 00000000000000f1
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141154 R12: 1ffff1100fc56520
R13: 1ffff1100fc56519 R14: ffff88807e2b2904 R15: ffff88807e2b28c0
FS: 00007fdf0904e880(0000) GS:ffff888125f3a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000080159018 CR3: 000000007e786000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 24 40 and $0x40,%al
2: 48 8b 4c 24 48 mov 0x48(%rsp),%rcx
7: 48 8d 1c c1 lea (%rcx,%rax,8),%rbx
b: 48 89 d8 mov %rbx,%rax
e: 48 c1 e8 03 shr $0x3,%rax
12: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
17: 44 0f b6 7c 24 1c movzbl 0x1c(%rsp),%r15d
1d: 74 08 je 0x27
1f: 48 89 df mov %rbx,%rdi
22: e8 3e 39 d5 f6 call 0xf6d53965
27: 4c 89 33 mov %r14,(%rbx)
* 2a: 49 8d 5c 24 48 lea 0x48(%r12),%rbx <-- trapping instruction
2f: 48 89 d8 mov %rbx,%rax
32: 48 c1 e8 03 shr $0x3,%rax
36: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
3b: 74 08 je 0x45
3d: 48 89 df mov %rbx,%rdi


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