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Message-ID: <69898d04.050a0220.3b3015.0070.GAE@google.com>
Date: Sun, 08 Feb 2026 23:30:12 -0800
From: syzbot ci <syzbot+cid20e3a9789516928@...kaller.appspotmail.com>
To: andrii@...nel.org, ast@...nel.org, bpf@...r.kernel.org,
daniel@...earbox.net, davem@...emloft.net, edumazet@...gle.com,
horms@...nel.org, kuba@...nel.org, linux-kernel@...r.kernel.org,
netdev@...r.kernel.org, pabeni@...hat.com, yangfeng59949@....com
Cc: syzbot@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: [syzbot ci] Re: bpf: test_run: Fix the null pointer dereference issue
in bpf_lwt_xmit_push_encap
syzbot ci has tested the following series
[v4] bpf: test_run: Fix the null pointer dereference issue in bpf_lwt_xmit_push_encap
https://lore.kernel.org/all/20260209015111.28144-1-yangfeng59949@163.com
* [PATCH v4] bpf: test_run: Fix the null pointer dereference issue in bpf_lwt_xmit_push_encap
and found the following issues:
* general protection fault in ip6_tnl_xmit
* general protection fault in tnl_update_pmtu
* general protection fault in wg_xmit
* general protection fault in xfrm_lookup_with_ifid
Full report is available here:
https://ci.syzbot.org/series/af38a4c5-943d-44d2-91e6-299e4e0a94db
***
general protection fault in ip6_tnl_xmit
tree: bpf-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git
base: db975debcb8c4cd367a78811bc1ba84c83f854bd
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c4ef1868-7d17-40c4-b5a7-b2d7bec3a6fe/config
C repro: https://ci.syzbot.org/findings/311bc7a0-3bf0-490c-b561-a21f38f4d8e9/c_repro
syz repro: https://ci.syzbot.org/findings/311bc7a0-3bf0-490c-b561-a21f38f4d8e9/syz_repro
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 UID: 0 PID: 5991 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:dst_neigh_lookup include/net/dst.h:404 [inline]
RIP: 0010:ip6_tnl_xmit+0x14a1/0x2af0 net/ipv6/ip6_tunnel.c:1123
Code: 74 12 4c 89 ef e8 af d8 ea f7 48 ba 00 00 00 00 00 fc ff df 4d 01 f4 49 83 c4 18 4d 8b 6d 00 49 83 c5 68 4c 89 e8 48 c1 e8 03 <80> 3c 10 00 74 08 4c 89 ef e8 81 d8 ea f7 4d 8b 5d 00 4c 89 ff 31
RSP: 0018:ffffc90003976e60 EFLAGS: 00010202
RAX: 000000000000000d RBX: 1ffff1102e6c7d07 RCX: ffff88810b2c57c0
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003977028 R08: ffff88810b2c57c0 R09: 0000000000000002
R10: 000000000000dd86 R11: 0000000000000000 R12: ffff88816a0ce066
R13: 0000000000000068 R14: ffff88816a0ce000 R15: ffffc90003977ba0
FS: 000055555f394500(0000) GS:ffff8882a9927000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30263fff CR3: 000000010d832000 CR4: 00000000000006f0
Call Trace:
<TASK>
ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1400 [inline]
ip6_tnl_start_xmit+0xc79/0x11d0 net/ipv6/ip6_tunnel.c:1448
__netdev_start_xmit include/linux/netdevice.h:5273 [inline]
netdev_start_xmit include/linux/netdevice.h:5282 [inline]
xmit_one net/core/dev.c:3853 [inline]
dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3869
__dev_queue_xmit+0x14dd/0x32a0 net/core/dev.c:4819
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
__bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153
____bpf_clone_redirect net/core/filter.c:2487 [inline]
bpf_clone_redirect+0x313/0x4b0 net/core/filter.c:2450
bpf_prog_2f59963de350c2d2+0x5e/0x67
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
bpf_test_run+0x354/0x830 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x13b4/0x1e00 net/bpf/test_run.c:1168
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4721
__sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6246
__do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff39439acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc03f9fef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ff394615fa0 RCX: 00007ff39439acb9
RDX: 0000000000000028 RSI: 00002000000000c0 RDI: 000000000000000a
RBP: 00007ff394408bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff394615fac R14: 00007ff394615fa0 R15: 00007ff394615fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dst_neigh_lookup include/net/dst.h:404 [inline]
RIP: 0010:ip6_tnl_xmit+0x14a1/0x2af0 net/ipv6/ip6_tunnel.c:1123
Code: 74 12 4c 89 ef e8 af d8 ea f7 48 ba 00 00 00 00 00 fc ff df 4d 01 f4 49 83 c4 18 4d 8b 6d 00 49 83 c5 68 4c 89 e8 48 c1 e8 03 <80> 3c 10 00 74 08 4c 89 ef e8 81 d8 ea f7 4d 8b 5d 00 4c 89 ff 31
RSP: 0018:ffffc90003976e60 EFLAGS: 00010202
RAX: 000000000000000d RBX: 1ffff1102e6c7d07 RCX: ffff88810b2c57c0
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003977028 R08: ffff88810b2c57c0 R09: 0000000000000002
R10: 000000000000dd86 R11: 0000000000000000 R12: ffff88816a0ce066
R13: 0000000000000068 R14: ffff88816a0ce000 R15: ffffc90003977ba0
FS: 000055555f394500(0000) GS:ffff8882a9927000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30263fff CR3: 000000010d832000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 74 12 je 0x14
2: 4c 89 ef mov %r13,%rdi
5: e8 af d8 ea f7 call 0xf7ead8b9
a: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
11: fc ff df
14: 4d 01 f4 add %r14,%r12
17: 49 83 c4 18 add $0x18,%r12
1b: 4d 8b 6d 00 mov 0x0(%r13),%r13
1f: 49 83 c5 68 add $0x68,%r13
23: 4c 89 e8 mov %r13,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ef mov %r13,%rdi
33: e8 81 d8 ea f7 call 0xf7ead8b9
38: 4d 8b 5d 00 mov 0x0(%r13),%r11
3c: 4c 89 ff mov %r15,%rdi
3f: 31 .byte 0x31
***
general protection fault in tnl_update_pmtu
tree: bpf-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git
base: db975debcb8c4cd367a78811bc1ba84c83f854bd
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c4ef1868-7d17-40c4-b5a7-b2d7bec3a6fe/config
C repro: https://ci.syzbot.org/findings/78a52206-e4f0-4a95-a881-32bbaab25810/c_repro
syz repro: https://ci.syzbot.org/findings/78a52206-e4f0-4a95-a881-32bbaab25810/syz_repro
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 UID: 0 PID: 5980 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:skb_dst_update_pmtu_no_confirm include/net/dst.h:565 [inline]
RIP: 0010:tnl_update_pmtu+0x52b/0x1190 net/ipv4/ip_tunnel.c:533
Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 ad 38 2a f8 4c 8b 3b 49 83 c7 50 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 87 38 2a f8 4d 8b 3f 4d 85 ff 8b 5c
RSP: 0018:ffffc90003d56e28 EFLAGS: 00010206
RAX: 000000000000000a RBX: ffffc90003d57ba8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffc90003d57ba0 RDI: 0000000000000000
RBP: ffffc90003d57ba0 R08: ffffffff89db4393 R09: ffffffff8e35a3a0
R10: ffffc90003d56de0 R11: fffff520007aadbe R12: ffff88816a305380
R13: ffff88816a3053d8 R14: 1ffff1102d460a7b R15: 0000000000000050
FS: 000055559418b500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30863fff CR3: 00000001bea06000 CR4: 00000000000006f0
Call Trace:
<TASK>
ip_tunnel_xmit+0xd36/0x2430 net/ipv4/ip_tunnel.c:805
__gre_xmit net/ipv4/ip_gre.c:490 [inline]
ipgre_xmit+0x8e6/0xc60 net/ipv4/ip_gre.c:694
__netdev_start_xmit include/linux/netdevice.h:5273 [inline]
netdev_start_xmit include/linux/netdevice.h:5282 [inline]
xmit_one net/core/dev.c:3853 [inline]
dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3869
__dev_queue_xmit+0x14dd/0x32a0 net/core/dev.c:4819
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
__bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153
____bpf_clone_redirect net/core/filter.c:2487 [inline]
bpf_clone_redirect+0x313/0x4b0 net/core/filter.c:2450
bpf_prog_7c64685fc60f7d44+0x5f/0x68
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
bpf_test_run+0x354/0x830 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x13b4/0x1e00 net/bpf/test_run.c:1168
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4721
__sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6246
__do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6668d9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcdef544a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f6669015fa0 RCX: 00007f6668d9acb9
RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a
RBP: 00007f6668e08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6669015fac R14: 00007f6669015fa0 R15: 00007f6669015fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_dst_update_pmtu_no_confirm include/net/dst.h:565 [inline]
RIP: 0010:tnl_update_pmtu+0x52b/0x1190 net/ipv4/ip_tunnel.c:533
Code: c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 ad 38 2a f8 4c 8b 3b 49 83 c7 50 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 87 38 2a f8 4d 8b 3f 4d 85 ff 8b 5c
RSP: 0018:ffffc90003d56e28 EFLAGS: 00010206
RAX: 000000000000000a RBX: ffffc90003d57ba8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffc90003d57ba0 RDI: 0000000000000000
RBP: ffffc90003d57ba0 R08: ffffffff89db4393 R09: ffffffff8e35a3a0
R10: ffffc90003d56de0 R11: fffff520007aadbe R12: ffff88816a305380
R13: ffff88816a3053d8 R14: 1ffff1102d460a7b R15: 0000000000000050
FS: 000055559418b500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30863fff CR3: 00000001bea06000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: c1 e8 03 shr $0x3,%eax
3: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1)
8: 74 08 je 0x12
a: 48 89 df mov %rbx,%rdi
d: e8 ad 38 2a f8 call 0xf82a38bf
12: 4c 8b 3b mov (%rbx),%r15
15: 49 83 c7 50 add $0x50,%r15
19: 4c 89 f8 mov %r15,%rax
1c: 48 c1 e8 03 shr $0x3,%rax
20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
27: fc ff df
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 74 08 je 0x38
30: 4c 89 ff mov %r15,%rdi
33: e8 87 38 2a f8 call 0xf82a38bf
38: 4d 8b 3f mov (%r15),%r15
3b: 4d 85 ff test %r15,%r15
3e: 8b .byte 0x8b
3f: 5c pop %rsp
***
general protection fault in wg_xmit
tree: bpf-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git
base: db975debcb8c4cd367a78811bc1ba84c83f854bd
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c4ef1868-7d17-40c4-b5a7-b2d7bec3a6fe/config
C repro: https://ci.syzbot.org/findings/9650e699-cf43-4d3b-841d-ae1a23f976f0/c_repro
syz repro: https://ci.syzbot.org/findings/9650e699-cf43-4d3b-841d-ae1a23f976f0/syz_repro
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 5985 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:dst_mtu include/net/dst.h:219 [inline]
RIP: 0010:wg_xmit+0x355/0xf70 drivers/net/wireguard/device.c:173
Code: 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 83 84 d9 fb 4d 8b 3f 49 83 c7 20 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 5d 84 d9 fb 4d 8b 3f 49 81 ff e0 38
RSP: 0018:ffffc90003cc7060 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffffc90003cc7ba0 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003cc7190 R08: ffffffff8fced577 R09: 1ffffffff1f9daae
R10: dffffc0000000000 R11: fffffbfff1f9daaf R12: ffffc90003cc70c0
R13: 1ffff1102ebe283b R14: ffff888175f14180 R15: 0000000000000020
FS: 00005555734f8500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30663fff CR3: 00000001704ae000 CR4: 00000000000006f0
Call Trace:
<TASK>
__netdev_start_xmit include/linux/netdevice.h:5273 [inline]
netdev_start_xmit include/linux/netdevice.h:5282 [inline]
xmit_one net/core/dev.c:3853 [inline]
dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3869
__dev_queue_xmit+0x14dd/0x32a0 net/core/dev.c:4819
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
__bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153
____bpf_clone_redirect net/core/filter.c:2487 [inline]
bpf_clone_redirect+0x313/0x4b0 net/core/filter.c:2450
bpf_prog_bd919e7baf24f63c+0x5f/0x68
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
bpf_test_run+0x354/0x830 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x13b4/0x1e00 net/bpf/test_run.c:1168
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4721
__sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6246
__do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc57899acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd806bfbf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fc578c15fa0 RCX: 00007fc57899acb9
RDX: 0000000000000050 RSI: 0000200000000080 RDI: 000000000000000a
RBP: 00007fc578a08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc578c15fac R14: 00007fc578c15fa0 R15: 00007fc578c15fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dst_mtu include/net/dst.h:219 [inline]
RIP: 0010:wg_xmit+0x355/0xf70 drivers/net/wireguard/device.c:173
Code: 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 83 84 d9 fb 4d 8b 3f 49 83 c7 20 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ff e8 5d 84 d9 fb 4d 8b 3f 49 81 ff e0 38
RSP: 0018:ffffc90003cc7060 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffffc90003cc7ba0 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003cc7190 R08: ffffffff8fced577 R09: 1ffffffff1f9daae
R10: dffffc0000000000 R11: fffffbfff1f9daaf R12: ffffc90003cc70c0
R13: 1ffff1102ebe283b R14: ffff888175f14180 R15: 0000000000000020
FS: 00005555734f8500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30663fff CR3: 00000001704ae000 CR4: 00000000000006f0
----------------
Code disassembly (best guess), 3 bytes skipped:
0: df 80 3c 08 00 74 filds 0x7400083c(%rax)
6: 08 4c 89 ff or %cl,-0x1(%rcx,%rcx,4)
a: e8 83 84 d9 fb call 0xfbd98492
f: 4d 8b 3f mov (%r15),%r15
12: 49 83 c7 20 add $0x20,%r15
16: 4c 89 f8 mov %r15,%rax
19: 48 c1 e8 03 shr $0x3,%rax
1d: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
24: fc ff df
* 27: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2b: 74 08 je 0x35
2d: 4c 89 ff mov %r15,%rdi
30: e8 5d 84 d9 fb call 0xfbd98492
35: 4d 8b 3f mov (%r15),%r15
38: 49 rex.WB
39: 81 .byte 0x81
3a: ff e0 jmp *%rax
3c: 38 .byte 0x38
***
general protection fault in xfrm_lookup_with_ifid
tree: bpf-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git
base: db975debcb8c4cd367a78811bc1ba84c83f854bd
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/c4ef1868-7d17-40c4-b5a7-b2d7bec3a6fe/config
C repro: https://ci.syzbot.org/findings/2ae3c5a4-d593-4385-8e69-f77a40c2382d/c_repro
syz repro: https://ci.syzbot.org/findings/2ae3c5a4-d593-4385-8e69-f77a40c2382d/syz_repro
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 5978 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:xfrm_lookup_with_ifid+0xe1/0x1af0 net/xfrm/xfrm_policy.c:3181
Code: 24 20 4d 8d 66 08 4c 89 e0 48 c1 e8 03 4d 89 ee 42 80 3c 28 00 74 08 4c 89 e7 e8 5a 1f 17 f8 4d 8b 24 24 4c 89 e0 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 94 17 00 00 41 0f b7 04 24 89 44 24 28
RSP: 0018:ffffc900045f6ea0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc900045f6f40 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900045f6f50
RBP: ffffc900045f6fb8 R08: ffffc900045f6f4f R09: 0000000000000000
R10: ffffc900045f6f40 R11: fffff520008bedea R12: 0000000000000000
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS: 00005555873db500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fa63fff CR3: 000000016e128000 CR4: 00000000000006f0
Call Trace:
<TASK>
xfrm_lookup net/xfrm/xfrm_policy.c:3336 [inline]
xfrm_lookup_route+0x3c/0x1c0 net/xfrm/xfrm_policy.c:3347
vti_xmit net/ipv4/ip_vti.c:217 [inline]
vti_tunnel_xmit+0x48e/0x18f0 net/ipv4/ip_vti.c:307
__netdev_start_xmit include/linux/netdevice.h:5273 [inline]
netdev_start_xmit include/linux/netdevice.h:5282 [inline]
xmit_one net/core/dev.c:3853 [inline]
dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3869
__dev_queue_xmit+0x14dd/0x32a0 net/core/dev.c:4819
dev_queue_xmit include/linux/netdevice.h:3381 [inline]
__bpf_tx_skb+0x18e/0x260 net/core/filter.c:2153
____bpf_clone_redirect net/core/filter.c:2487 [inline]
bpf_clone_redirect+0x313/0x4b0 net/core/filter.c:2450
bpf_prog_e16758452f539c38+0x5f/0x68
bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
bpf_test_run+0x354/0x830 net/bpf/test_run.c:423
bpf_prog_test_run_skb+0x13b4/0x1e00 net/bpf/test_run.c:1168
bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4721
__sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6246
__do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6339
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f722f59acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff2a77bfd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f722f815fa0 RCX: 00007f722f59acb9
RDX: 000000000000002c RSI: 0000200000000080 RDI: 000000000000000a
RBP: 00007f722f608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f722f815fac R14: 00007f722f815fa0 R15: 00007f722f815fa0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:xfrm_lookup_with_ifid+0xe1/0x1af0 net/xfrm/xfrm_policy.c:3181
Code: 24 20 4d 8d 66 08 4c 89 e0 48 c1 e8 03 4d 89 ee 42 80 3c 28 00 74 08 4c 89 e7 e8 5a 1f 17 f8 4d 8b 24 24 4c 89 e0 48 c1 e8 03 <42> 0f b6 04 30 84 c0 0f 85 94 17 00 00 41 0f b7 04 24 89 44 24 28
RSP: 0018:ffffc900045f6ea0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc900045f6f40 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900045f6f50
RBP: ffffc900045f6fb8 R08: ffffc900045f6f4f R09: 0000000000000000
R10: ffffc900045f6f40 R11: fffff520008bedea R12: 0000000000000000
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS: 00005555873db500(0000) GS:ffff88818e327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fa63fff CR3: 000000016e128000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 24 20 and $0x20,%al
2: 4d 8d 66 08 lea 0x8(%r14),%r12
6: 4c 89 e0 mov %r12,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 4d 89 ee mov %r13,%r14
10: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
15: 74 08 je 0x1f
17: 4c 89 e7 mov %r12,%rdi
1a: e8 5a 1f 17 f8 call 0xf8171f79
1f: 4d 8b 24 24 mov (%r12),%r12
23: 4c 89 e0 mov %r12,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 94 17 00 00 jne 0x17cb
37: 41 0f b7 04 24 movzwl (%r12),%eax
3c: 89 44 24 28 mov %eax,0x28(%rsp)
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@...kaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@...glegroups.com.
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