WARNING in __netif_receive_skb_core

Status: upstream: reported C repro on 2026/09/15 15:56
Subsystems: can
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+1aae11dc8d42ec1a87ec@syzkaller.appspotmail.com
First crash: 1d01h, last: 22h34m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
ca584b60 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in __netif_receive_skb_core 2026/09/15 02:21 2026/09/15 02:21 2026/09/15 03:19 81a27d1a
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [can?] WARNING in __netif_receive_skb_core 0 (1) 2026/09/15 15:56

Sample crash report:
------------[ cut here ]------------
1
WARNING: ./include/linux/skbuff.h:3003 at skb_reset_mac_len include/linux/skbuff.h:3003 [inline], CPU#0: kworker/u8:1/13
WARNING: ./include/linux/skbuff.h:3003 at __netif_receive_skb_core.constprop.0+0x1706/0x3530 net/core/dev.c:6061, CPU#0: kworker/u8:1/13
Modules linked in:
CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Workqueue: events_unbound flush_to_ldisc
RIP: 0010:skb_reset_mac_len include/linux/skbuff.h:3003 [inline]
RIP: 0010:__netif_receive_skb_core.constprop.0+0x1706/0x3530 net/core/dev.c:6061
Code: de 4c 8b bc 24 e8 00 00 00 e8 86 f7 6b f8 85 db 0f 88 11 f2 ff ff 31 db 4d 8d af 81 00 00 00 e9 01 ed ff ff e8 fb fc 6b f8 90 <0f> 0b 90 31 db e9 43 eb ff ff e8 eb fc 6b f8 e8 66 af 4f f8 31 ff
RSP: 0018:ffffc90000007990 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000040 RCX: 0000000000000101
RDX: ffff88801f2a0000 RSI: ffffffff89a02015 RDI: ffff88801f2a0000
RBP: 000000000000ffff R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000001 R12: ffff888075f88140
R13: ffffc90000007c10 R14: ffff888075f88140 R15: ffff888075f88140
FS:  0000000000000000(0000) GS:ffff888123b59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd21e26870 CR3: 00000000729f5000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6262
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377
 process_backlog+0x487/0x1600 net/core/dev.c:6728
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787
 napi_poll net/core/dev.c:7850 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:8007
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 do_softirq kernel/softirq.c:546 [inline]
 do_softirq+0xaf/0xf0 kernel/softirq.c:533
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 netif_rx net/core/dev.c:5837 [inline]
 netif_rx+0x93/0xb0 net/core/dev.c:5826
 slcan_bump_err drivers/net/can/slcan/slcan-core.c:448 [inline]
 slcan_bump drivers/net/can/slcan/slcan-core.c:463 [inline]
 slcan_unesc drivers/net/can/slcan/slcan-core.c:476 [inline]
 slcan_receive_buf+0x1a66/0x1f30 drivers/net/can/slcan/slcan-core.c:807
 tty_ldisc_receive_buf+0x15a/0x1a0 drivers/tty/tty_buffer.c:398
 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:452 [inline]
 flush_to_ldisc+0x26b/0x730 drivers/tty/tty_buffer.c:502
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/14 22:05 upstream 704340f1cd0d 924033e8 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 21:23 upstream 704340f1cd0d 924033e8 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 21:18 upstream 704340f1cd0d 924033e8 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in __netif_receive_skb_core
2026/09/14 20:44 upstream 704340f1cd0d 924033e8 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 20:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 924033e8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __netif_receive_skb_core
2026/09/14 20:16 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 924033e8 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __netif_receive_skb_core
2026/09/14 20:09 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in __netif_receive_skb_core
2026/09/14 20:09 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in __netif_receive_skb_core
2026/09/14 19:50 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 19:50 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 19:47 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in __netif_receive_skb_core
2026/09/14 20:22 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __netif_receive_skb_core
2026/09/14 20:22 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in __netif_receive_skb_core
2026/09/14 19:43 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in __netif_receive_skb_core
2026/09/14 19:43 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in __netif_receive_skb_core
2026/09/14 19:42 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in __netif_receive_skb_core
2026/09/14 20:29 linux-next 9d80aa4617b3 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __netif_receive_skb_core
2026/09/14 20:26 linux-next 9d80aa4617b3 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __netif_receive_skb_core
2026/09/14 20:01 linux-next 9d80aa4617b3 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __netif_receive_skb_core
2026/09/14 19:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __netif_receive_skb_core
2026/09/14 19:39 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5445d6419962 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __netif_receive_skb_core
2026/09/14 21:27 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 73ae59e97596 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in __netif_receive_skb_core
2026/09/14 21:26 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 73ae59e97596 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in __netif_receive_skb_core
* Struck through repros no longer work on HEAD.