syzbot


WARNING in __skb_flow_dissect (6)

Status: internal: reported on 2024/05/07 03:25
Subsystems: net
[Documentation on labels]
Fix commit: net: add and use skb_get_hash_net
Patched on: [ci-upstream-bpf-next-kasan-gce ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci2-upstream-net-next-test-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 67d, last: 67d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __skb_flow_dissect net syz 3 2103d 2104d 11/27 fixed on 2018/10/11 18:37
upstream WARNING in __skb_flow_dissect (5) net 1 107d 107d 0/27 closed as invalid on 2024/04/26 11:59
upstream WARNING in __skb_flow_dissect (3) net syz 224 2006d 2095d 11/27 fixed on 2019/03/06 07:43
upstream WARNING in __skb_flow_dissect (4) net C error 6 616d 625d 22/27 fixed on 2023/02/24 13:50

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9391 at net/core/flow_dissector.c:1104 __skb_flow_dissect+0xc73/0x7d00 net/core/flow_dissector.c:1104
Modules linked in:
CPU: 0 PID: 9391 Comm: syz-executor.4 Not tainted 6.9.0-rc6-syzkaller-01486-g8c4e4798123f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__skb_flow_dissect+0xc73/0x7d00 net/core/flow_dissector.c:1104
Code: 65 00 00 80 3d 6e 20 42 06 01 0f 85 8a 65 00 00 e8 a2 a2 44 f8 e9 99 fa ff ff e8 98 a2 44 f8 e9 eb f9 ff ff e8 8e a2 44 f8 90 <0f> 0b 90 e9 de 03 00 00 e8 80 a2 44 f8 c6 05 39 20 42 06 01 48 c7
RSP: 0018:ffffc900000069e0 EFLAGS: 00010246
RAX: ffffffff895187f2 RBX: 0000000000000000 RCX: ffff88807d211e00
RDX: 0000000000000301 RSI: 0000000000000000 RDI: ffff888065916de0
RBP: ffffc90000007008 R08: ffffffff89517ddd R09: 0000000000000000
R10: ffffc900000070e0 R11: fffff52000000e26 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff8fa99b22 R15: ffffffff8fa99b18
FS:  00007fb2ae4276c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31c21000 CR3: 000000006ac4c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 skb_flow_dissect_flow_keys include/linux/skbuff.h:1536 [inline]
 ___skb_get_hash+0x55/0x800 net/core/flow_dissector.c:1799
 __skb_get_hash+0xbc/0x410 net/core/flow_dissector.c:1864
 skb_get_hash include/linux/skbuff.h:1578 [inline]
 nft_trace_init+0x1e5/0x440 net/netfilter/nf_tables_trace.c:320
 nft_do_chain+0x1c42/0x1da0 net/netfilter/nf_tables_core.c:268
 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:269 [inline]
 __ip6_local_out+0x6fa/0x800 net/ipv6/output_core.c:143
 ip6_local_out+0x26/0x70 net/ipv6/output_core.c:153
 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
 udp_tunnel6_xmit_skb+0x590/0x9d0 net/ipv6/ip6_udp_tunnel.c:111
 tipc_udp_xmit+0x6a3/0xa10 net/tipc/udp_media.c:217
 tipc_bearer_xmit_skb+0x2f5/0x460 net/tipc/bearer.c:571
 tipc_disc_timeout+0x5ee/0x760 net/tipc/discover.c:338
 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793
 expire_timers kernel/time/timer.c:1844 [inline]
 __run_timers kernel/time/timer.c:2418 [inline]
 __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2429
 run_timer_base kernel/time/timer.c:2438 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448
 __do_softirq+0x2c6/0x980 kernel/softirq.c:554
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:unwind_next_frame+0x194/0x2a00
Code: 48 89 44 24 78 42 0f b6 04 30 84 c0 48 8b 5c 24 20 48 89 54 24 10 0f 85 f6 1f 00 00 48 0f be 2a 48 8b 44 24 30 42 80 3c 30 00 <74> 08 48 89 df e8 52 d3 b9 00 48 03 2b 48 8d 75 ff 31 ff e8 44 de
RSP: 0018:ffffc90004b86888 EFLAGS: 00000246
RAX: 1ffff92000970d35 RBX: ffffc90004b869a8 RCX: ffff88807d211e00
RDX: ffffc90004b86995 RSI: 0000000000000001 RDI: ffffffff81415031
RBP: 0000000000000000 R08: ffffffff81415011 R09: ffffc90004b86a50
R10: 0000000000000003 R11: ffffffff818209c0 R12: ffffc90004b86960
R13: ffffc90004b869b0 R14: dffffc0000000000 R15: ffffffff8991f78a
 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfb/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x75/0x3f0 mm/page_owner.c:302
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 __free_pages_ok+0xc60/0xd90 mm/page_alloc.c:1270
 __folio_put_large+0x168/0x1d0 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 folio_put include/linux/mm.h:1508 [inline]
 free_large_kmalloc+0x105/0x1c0 mm/slub.c:4361
 kfree+0x1ca/0x3a0 mm/slub.c:4384
 __qdisc_destroy+0x150/0x410 net/sched/sch_generic.c:1072
 notify_and_destroy net/sched/sch_api.c:1076 [inline]
 qdisc_graft+0x1237/0x1580 net/sched/sch_api.c:1173
 tc_modify_qdisc+0xf47/0x1e40 net/sched/sch_api.c:1788
 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6579
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb2ad67dca9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb2ae4270c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fb2ad7abf80 RCX: 00007fb2ad67dca9
RDX: 0000000000000000 RSI: 0000000020001200 RDI: 0000000000000005
RBP: 00007fb2ad6c947e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fb2ad7abf80 R15: 00007ffe3f196498
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 89 44 24 78       	mov    %rax,0x78(%rsp)
   5:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
   a:	84 c0                	test   %al,%al
   c:	48 8b 5c 24 20       	mov    0x20(%rsp),%rbx
  11:	48 89 54 24 10       	mov    %rdx,0x10(%rsp)
  16:	0f 85 f6 1f 00 00    	jne    0x2012
  1c:	48 0f be 2a          	movsbq (%rdx),%rbp
  20:	48 8b 44 24 30       	mov    0x30(%rsp),%rax
  25:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1)
* 2a:	74 08                	je     0x34 <-- trapping instruction
  2c:	48 89 df             	mov    %rbx,%rdi
  2f:	e8 52 d3 b9 00       	call   0xb9d386
  34:	48 03 2b             	add    (%rbx),%rbp
  37:	48 8d 75 ff          	lea    -0x1(%rbp),%rsi
  3b:	31 ff                	xor    %edi,%edi
  3d:	e8                   	.byte 0xe8
  3e:	44                   	rex.R
  3f:	de                   	.byte 0xde

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/07 03:24 net-next 8c4e4798123f c035c6de .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in __skb_flow_dissect
* Struck through repros no longer work on HEAD.