alloc_skb include/linux/skbuff.h:995 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1197 [inline] netlink_sendmsg+0x9f6/0xc50 net/netlink/af_netlink.c:1892 kasan: GPF could be caused by NULL-ptr deref or user memory access sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 11900 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51 Code: 0f 84 30 52 85 04 48 b8 00 02 00 00 00 00 ad de 49 39 c4 0f 84 31 52 85 04 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 51 49 8b 14 24 48 39 ea 0f 85 e8 51 85 04 49 8d 7d RSP: 0018:ffff88804de8f4e8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88809dfdcdc0 RCX: ffffffff814bdebb RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88809dfdd0e8 RBP: ffff88809dfdd0e0 R08: 0000000000000001 R09: fffffbfff15cead8 R10: ffffffff8ae756c3 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809dfdd040 R15: ffff88809dfdd0e8 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 FS: 00007f90b6586700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb318299710 CR3: 00000000aae1b000 CR4: 00000000003406e0 DR0: 00000000000000ff DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 __list_del_entry include/linux/list.h:117 [inline] list_del include/linux/list.h:125 [inline] cbs_destroy+0x81/0x280 net/sched/sch_cbs.c:448 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f60c81b9059 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 b8 ff ff ff f7 d8 64 89 01 48 qdisc_create+0xb70/0x1130 net/sched/sch_api.c:1204 RSP: 002b:00007f60c6b2e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f60c82cbf60 RCX: 00007f60c81b9059 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004 tc_modify_qdisc+0x50d/0x1a80 net/sched/sch_api.c:1572 RBP: 00007f60c6b2e1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff5462432f R14: 00007f60c6b2e300 R15: 0000000000022000 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f90b7c11059 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f90b6586168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f90b7d23f60 RCX: 00007f90b7c11059 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004 RBP: 00007f90b65861d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd070d559f R14: 00007f90b6586300 R15: 0000000000022000 Modules linked in: ---[ end trace 7d7a98794f860e89 ]--- RIP: 0010:__list_del_entry_valid+0x81/0xf0 lib/list_debug.c:51 Code: 0f 84 30 52 85 04 48 b8 00 02 00 00 00 00 ad de 49 39 c4 0f 84 31 52 85 04 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 75 51 49 8b 14 24 48 39 ea 0f 85 e8 51 85 04 49 8d 7d RSP: 0018:ffff88804de8f4e8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88809dfdcdc0 RCX: ffffffff814bdebb RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88809dfdd0e8 RBP: ffff88809dfdd0e0 R08: 0000000000000001 R09: fffffbfff15cead8 R10: ffffffff8ae756c3 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88809dfdd040 R15: ffff88809dfdd0e8 FS: 00007f90b6586700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb318299710 CR3: 00000000aae1b000 CR4: 00000000003406e0 DR0: 00000000000000ff DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 0f 84 30 52 85 04 je 0x4855236 6: 48 b8 00 02 00 00 00 movabs $0xdead000000000200,%rax d: 00 ad de 10: 49 39 c4 cmp %rax,%r12 13: 0f 84 31 52 85 04 je 0x485524a 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 4c 89 e2 mov %r12,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 75 51 jne 0x81 30: 49 8b 14 24 mov (%r12),%rdx 34: 48 39 ea cmp %rbp,%rdx 37: 0f 85 e8 51 85 04 jne 0x4855225 3d: 49 rex.WB 3e: 8d .byte 0x8d 3f: 7d .byte 0x7d