Re: [syzbot] [mm?] [usb?] WARNING in __alloc_skb (4)

syzbot
2025-09-20T01:15:04Z

Hello,

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

------------[ cut here ]------------
WARNING: mm/page_alloc.c:5135 at __alloc_frozen_pages_noprof+0x2c8/0x370 mm/page_alloc.c:5135, CPU#1: dhcpcd/5527
Modules linked in:
CPU: 1 UID: 0 PID: 5527 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__alloc_frozen_pages_noprof+0x2c8/0x370 mm/page_alloc.c:5135
Code: 74 10 4c 89 e7 89 54 24 0c e8 f4 b7 0d 00 8b 54 24 0c 49 83 3c 24 00 0f 85 a5 fe ff ff e9 a6 fe ff ff c6 05 25 c9 b7 0d 01 90 <0f> 0b 90 e9 18 ff ff ff a9 00 00 08 00 48 8b 4c 24 10 4c 8d 44 24
RSP: 0018:ffffc90000a086e0 EFLAGS: 00010246
RAX: ffffc90000a08700 RBX: 0000000000000014 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90000a08748
RBP: ffffc90000a087c8 R08: ffffc90000a08747 R09: 0000000000000000
R10: ffffc90000a08720 R11: fffff520001410e9 R12: 0000000000000000
R13: 1ffff920001410e0 R14: 0000000000060820 R15: dffffc0000000000
FS: 00007f141af9a740(0000) GS:ffff8881258a2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fc915d6138 CR3: 000000007caf0000 CR4: 00000000003526f0
Call Trace:
<IRQ>
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:5543
__kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:5574
__do_kmalloc_node mm/slub.c:5590 [inline]
__kmalloc_node_track_caller_noprof+0x133/0x800 mm/slub.c:5711
kmalloc_reserve+0x1b8/0x290 net/core/skbuff.c:609
__alloc_skb+0x142/0x2d0 net/core/skbuff.c:670
__netdev_alloc_skb+0x108/0x970 net/core/skbuff.c:734
rx_submit+0x100/0xab0 drivers/net/usb/usbnet.c:-1
rx_alloc_submit+0xa6/0x140 drivers/net/usb/usbnet.c:1538
usbnet_bh+0x9a5/0xd70 drivers/net/usb/usbnet.c:1607
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
bh_worker+0x2b1/0x600 kernel/workqueue.c:3607
tasklet_action+0xc/0x70 kernel/softirq.c:952
handle_softirqs+0x286/0x870 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:1052 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:queue_work_on+0x1f7/0x270 kernel/workqueue.c:2397
Code: 4d 85 ff 75 16 e8 b9 ce 35 00 eb 15 e8 b2 ce 35 00 e8 9d 57 03 0a 4d 85 ff 74 ea e8 a3 ce 35 00 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2e 00 00 00 00 66 43 c7 44 2e 09 00 00 43 c6 44 2e 0b 00
RSP: 0018:ffffc900034a7600 EFLAGS: 00000293
RAX: ffffffff818a4a7d RBX: ffff8880560d9201 RCX: ffff88802eb3bc80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900034a76f8 R08: ffffffff8fe4db77 R09: 1ffffffff1fc9b6e
R10: dffffc0000000000 R11: fffffbfff1fc9b6f R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff92000694ec8 R15: 0000000000000200
queue_work include/linux/workqueue.h:669 [inline]
usbnet_open+0x5c6/0xce0 drivers/net/usb/usbnet.c:958
__dev_open+0x470/0x880 net/core/dev.c:1682
__dev_change_flags+0x1ea/0x6d0 net/core/dev.c:9630
netif_change_flags+0x88/0x1a0 net/core/dev.c:9693
dev_change_flags+0x130/0x260 net/core/dev_api.c:68
devinet_ioctl+0xbb4/0x1b50 net/ipv4/devinet.c:1199
inet_ioctl+0x3c0/0x4c0 net/ipv4/af_inet.c:1003
sock_do_ioctl+0xdc/0x300 net/socket.c:1241
sock_ioctl+0x576/0x790 net/socket.c:1362
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f141b09a378
Code: 00 00 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 07 89 d0 c3 0f 1f 40 00 48 8b 15 49 3a 0d
RSP: 002b:00007fff3eacfd18 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000012 RCX: 00007f141b09a378
RDX: 00007fff3eadff10 RSI: 0000000000008914 RDI: 0000000000000012
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff3eaf00b0
R13: 00007f141af9a6c8 R14: 0000000000000028 R15: 0000000000008914
</TASK>
----------------
Code disassembly (best guess):
0: 4d 85 ff test %r15,%r15
3: 75 16 jne 0x1b
5: e8 b9 ce 35 00 call 0x35cec3
a: eb 15 jmp 0x21
c: e8 b2 ce 35 00 call 0x35cec3
11: e8 9d 57 03 0a call 0xa0357b3
16: 4d 85 ff test %r15,%r15
19: 74 ea je 0x5
1b: e8 a3 ce 35 00 call 0x35cec3
20: fb sti
21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp)
28: e0 45
* 2a: 4b c7 04 2e 00 00 00 movq $0x0,(%r14,%r13,1) <-- trapping instruction
31: 00
32: 66 43 c7 44 2e 09 00 movw $0x0,0x9(%r14,%r13,1)
39: 00
3a: 43 c6 44 2e 0b 00 movb $0x0,0xb(%r14,%r13,1)

Tested on:

commit: 846bd222 Add linux-next specific files for 20250919
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=16b15c7c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=135377594f35b576
dashboard link: https://syzkaller.appspot.com/bug?extid=5a2250fd91b28106c37b
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch: https://syzkaller.appspot.com/x/patch.diff?x=13f2a0e2580000