netlink: 'syz.3.2296': attribute type 10 has an invalid length. skbuff: skb_under_panic: text:ffffffff89ef1f08 len:-1783546478 put:-1783546484 head:ffff88804f6bc9c0 data:ffff887fb9ba8c74 tail:0x46 end:0x180 dev:bond0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:212! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 14380 Comm: syz.3.2296 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:skb_panic+0x157/0x1d0 net/core/skbuff.c:212 Code: b6 04 01 84 c0 74 04 3c 03 7e 21 41 56 8b 4b 70 45 89 e8 48 c7 c7 20 d2 bf 8c 41 57 56 48 89 ee 52 4c 89 e2 e8 0a 8f 6a f8 90 <0f> 0b 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 04 c2 f4 f8 4c RSP: 0018:ffffc9001c36f858 EFLAGS: 00010282 RAX: 0000000000000098 RBX: ffff888035778640 RCX: ffffc9000cd4c000 RDX: 0000000000000000 RSI: ffffffff819c1a36 RDI: 0000000000000005 RBP: ffffffff8cbfe5e0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: fffffffffffdae58 R12: ffffffff89ef1f08 R13: 0000000095b13d8c R14: ffff888051a14120 R15: 0000000000000180 FS: 00007f02d26d66c0(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000037c030 CR3: 0000000074dec000 CR4: 00000000003526f0 Call Trace: skb_under_panic net/core/skbuff.c:222 [inline] skb_push+0xca/0xf0 net/core/skbuff.c:2602 ipgre_header+0x68/0x530 net/ipv4/ip_gre.c:895 dev_hard_header include/linux/netdevice.h:3419 [inline] pppoe_sendmsg+0x570/0x7b0 drivers/net/ppp/pppoe.c:897 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmmsg+0x200/0x420 net/socket.c:2773 __do_sys_sendmmsg net/socket.c:2800 [inline] __se_sys_sendmmsg net/socket.c:2797 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797 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: 0033:0x7f02d178eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f02d26d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f02d19e5fa0 RCX: 00007f02d178eec9 RDX: 00000000000003e8 RSI: 0000200000002340 RDI: 000000000000000d RBP: 00007f02d1811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f02d19e6038 R14: 00007f02d19e5fa0 R15: 00007ffeac60d038 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:skb_panic+0x157/0x1d0 net/core/skbuff.c:212 Code: b6 04 01 84 c0 74 04 3c 03 7e 21 41 56 8b 4b 70 45 89 e8 48 c7 c7 20 d2 bf 8c 41 57 56 48 89 ee 52 4c 89 e2 e8 0a 8f 6a f8 90 <0f> 0b 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 04 c2 f4 f8 4c RSP: 0018:ffffc9001c36f858 EFLAGS: 00010282 RAX: 0000000000000098 RBX: ffff888035778640 RCX: ffffc9000cd4c000 RDX: 0000000000000000 RSI: ffffffff819c1a36 RDI: 0000000000000005 RBP: ffffffff8cbfe5e0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: fffffffffffdae58 R12: ffffffff89ef1f08 R13: 0000000095b13d8c R14: ffff888051a14120 R15: 0000000000000180 FS: 00007f02d26d66c0(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f20063b6358 CR3: 0000000074dec000 CR4: 00000000003526f0