syzbot


kernel BUG in pskb_expand_head (2)

Status: upstream: reported on 2026/04/05 20:08
Reported-by: syzbot+7db97d3b3ca78574a65c@syzkaller.appspotmail.com
First crash: 5d12h, last: 5d12h
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 kernel BUG in pskb_expand_head (2) origin:lts-only -1 C done 7 233d 266d 2/3 upstream: reported C repro on 2025/07/18 14:25
android-5-15 kernel BUG in pskb_expand_head -1 C 17 221d 261d 0/2 auto-obsoleted due to no activity on 2025/11/11 01:09
android-6-1 kernel BUG in pskb_expand_head -1 1 1038d 1038d 0/2 auto-obsoleted due to no activity on 2023/09/05 19:11
upstream kernel BUG in pskb_expand_head (4) intel-wired-lan -1 1 408d 408d 28/29 fixed on 2025/06/10 16:19
upstream kernel BUG in pskb_expand_head (3) net -1 1 656d 656d 0/29 closed as invalid on 2024/09/04 18:07
upstream kernel BUG in pskb_expand_head (2) bpf net -1 10 1051d 1066d 0/29 auto-obsoleted due to no activity on 2023/08/23 09:08
linux-5.15 kernel BUG in pskb_expand_head -1 1 1090d 1090d 0/3 auto-obsoleted due to no activity on 2023/08/14 13:19
upstream kernel BUG in llc_sap_action_send_xid_c net -1 C error 61 1613d 1827d 20/29 fixed on 2021/11/10 00:50
upstream kernel BUG in pskb_expand_head net -1 C done 1600 1156d 1608d 22/29 fixed on 2023/02/25 08:02
linux-6.1 kernel BUG in pskb_expand_head -1 1 1046d 1046d 0/3 auto-obsoleted due to no activity on 2023/09/07 17:22

Sample crash report:
bond1: (slave gre1): Setting fail_over_mac to active for active-backup mode
bond1: (slave gre1): making interface the new active one
device gre1 entered promiscuous mode
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:1839!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5442 Comm: syz.3.332 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026
pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : pskb_expand_head+0xfd4/0x1030 net/core/skbuff.c:1839
lr : pskb_expand_head+0xfd4/0x1030 net/core/skbuff.c:1839
sp : ffff800020f46580
x29: ffff800020f465e0 x28: 00000000000000c0 x27: 0000000000000000
x26: dfff800000000000 x25: 0000000000000a20 x24: 52e28000106a5e5c
x23: ffff0000c41c8000 x22: ffff0000d7f0d028 x21: 00000000ffff7fe0
x20: ffff0000e00d520c x19: ffff0000e00d5140 x18: ffff800011b9bf60
x17: ffff80001835a000 x16: ffff8000082d92bc x15: ffff80000fd49dec
x14: 0000000000000001 x13: 1fffe0001ece201c x12: 0000000000080000
x11: 000000000007ffff x10: ffff800029fef000 x9 : ffff80000fd78928
x8 : 0000000000080000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000018 x4 : ffff0000d7f0d028 x3 : 0000000000000a20
x2 : 0000000000000000 x1 : 00000000ffff7fe0 x0 : 0000000000000000
Call trace:
 pskb_expand_head+0xfd4/0x1030 net/core/skbuff.c:1839
 ipgre_header+0xd8/0x4bc net/ipv4/ip_gre.c:863
 dev_hard_header include/linux/netdevice.h:3103 [inline]
 arp_create+0x2b8/0x7ec net/ipv4/arp.c:577
 arp_send_dst net/ipv4/arp.c:314 [inline]
 arp_send+0xa8/0x11c net/ipv4/arp.c:328
 inetdev_send_gratuitous_arp net/ipv4/devinet.c:1528 [inline]
 inetdev_event+0xdb0/0x12d8 net/ipv4/devinet.c:1598
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:2014 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
 call_netdevice_notifiers+0x110/0x198 net/core/dev.c:2066
 bond_change_active_slave+0x1ef8/0x2fa0 drivers/net/bonding/bond_main.c:-1
 bond_select_active_slave+0x724/0xa78 drivers/net/bonding/bond_main.c:1314
 bond_enslave+0x1e08/0x3178 drivers/net/bonding/bond_main.c:2255
 do_set_master net/core/rtnetlink.c:2630 [inline]
 rtnl_newlink_create net/core/rtnetlink.c:3439 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3642 [inline]
 rtnl_newlink+0x175c/0x1a50 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x698/0xcdc net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x218/0x3e8 net/netlink/af_netlink.c:2511
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6168
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x60c/0x814 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6f4/0x9c0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5c8/0x938 net/socket.c:2518
 ___sys_sendmsg net/socket.c:2572 [inline]
 __sys_sendmsg+0x288/0x374 net/socket.c:2601
 __do_sys_sendmsg net/socket.c:2610 [inline]
 __se_sys_sendmsg net/socket.c:2608 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2608
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: aa1c03e0 962912b5 d4210000 961ccb1d (d4210000) 
---[ end trace 0000000000000000 ]---

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/05 20:07 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 kernel BUG in pskb_expand_head
2026/04/05 20:07 linux-6.1.y 1989cd3d56e2 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 kernel BUG in pskb_expand_head
* Struck through repros no longer work on HEAD.