The following kernel crash was noticed on x86_64 running selftests net
udpgso_bench.sh
on Linux next-20250905 tag.
Regression Analysis:
- New regression? yes
- Reproducibility? Re-validation is in progress
First seen on next-20250905
Bad: next-20250905
Good: next-20250904
Test regression: next-20250905 x86_64 selftests net BUG kernel NULL
pointer dereference zerocopy_fill_skb_from_iter
Reported-by: Linux Kernel Functional Testing <l...@linaro.org>
x86_64:
Test:
* selftests: net: udpgso_bench.sh
Test error:
selftests: net: udpgso_bench.sh
ipv4
tcp
<trim>
# tcp zerocopy
[ 991.110488] SELinux: unrecognized netlink message: protocol=4
nlmsg_type=19 sclass=netlink_tcpdiag_socket pid=64835 comm=ss
# RTNETLINK answers: Invalid argument
[ 991.129878] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 991.136850] #PF: supervisor read access in kernel mode
[ 991.141986] #PF: error_code(0x0000) - not-present page
[ 991.147118] PGD 0 P4D 0
[ 991.149657] Oops: Oops: 0000 [#1] SMP PTI
[ 991.153661] CPU: 0 UID: 0 PID: 64842 Comm: udpgso_bench_tx Tainted:
G S 6.17.0-rc4-next-20250905 #1 PREEMPT(voluntary)
[ 991.165907] Tainted: [S]=CPU_OUT_OF_SPEC
[ 991.169825] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS
2.7 12/07/2021
[ 991.177209] RIP: 0010:zerocopy_fill_skb_from_iter
(include/linux/page-flags.h:284)
[ 991.182954] Code: 4d 85 c0 0f 84 04 01 00 00 44 39 c7 41 0f 4d f8 4c
63 de 4a 8b 54 dc 30 49 89 d6 4d 29 ce 49 c1 fe 06 49 d3 ee 4d 85 f6
74 24 <48> 8b 4a 08 f6 c1 01 0f 85 cb 00 00 00 0f 1f 44 00 00 31 c9 48
f7
All code
========
0: 4d 85 c0 test %r8,%r8
3: 0f 84 04 01 00 00 je 0x10d
9: 44 39 c7 cmp %r8d,%edi
c: 41 0f 4d f8 cmovge %r8d,%edi
10: 4c 63 de movslq %esi,%r11
13: 4a 8b 54 dc 30 mov 0x30(%rsp,%r11,8),%rdx
18: 49 89 d6 mov %rdx,%r14
1b: 4d 29 ce sub %r9,%r14
1e: 49 c1 fe 06 sar $0x6,%r14
22: 49 d3 ee shr %cl,%r14
25: 4d 85 f6 test %r14,%r14
28: 74 24 je 0x4e
2a:* 48 8b 4a 08 mov 0x8(%rdx),%rcx <-- trapping instruction
2e: f6 c1 01 test $0x1,%cl
31: 0f 85 cb 00 00 00 jne 0x102
37: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
3c: 31 c9 xor %ecx,%ecx
3e: 48 rex.W
3f: f7 .byte 0xf7
Code starting with the faulting instruction
===========================================
0: 48 8b 4a 08 mov 0x8(%rdx),%rcx
4: f6 c1 01 test $0x1,%cl
7: 0f 85 cb 00 00 00 jne 0xd8
d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
12: 31 c9 xor %ecx,%ecx
14: 48 rex.W
15: f7 .byte 0xf7
[ 991.201691] RSP: 0018:ffffb11281d0ba90 EFLAGS: 00010202
[ 991.206910] RAX: ffffe14ec4208000 RBX: 0000000000005000 RCX: 0000000000000009
[ 991.214033] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000001000
[ 991.221156] RBP: ffffb11281d0bb88 R08: 00000000000020ff R09: ffffe14ec4208000
[ 991.228280] R10: 0000000000000005 R11: 0000000000000006 R12: ffff96b4825f4200
[ 991.235406] R13: 0000000000000001 R14: 000000003d6277bf R15: 0000000000000000
[ 991.242529] FS: 00007f41e80b9740(0000) GS:ffff96b83bc1b000(0000)
knlGS:0000000000000000
[ 991.250608] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 991.256378] CR2: 0000000000000008 CR3: 0000000106c42003 CR4: 00000000003706f0
[ 991.263513] Call Trace:
[ 991.265956] <TASK>
[ 991.268055] __zerocopy_sg_from_iter (net/core/datagram.c:?)
[ 991.272674] ? kmalloc_reserve (net/core/skbuff.c:581)
[ 991.276599] skb_zerocopy_iter_stream (net/core/skbuff.c:1867)
[ 991.281219] tcp_sendmsg_locked (net/ipv4/tcp.c:1283)
[ 991.285493] tcp_sendmsg (net/ipv4/tcp.c:1393)
[ 991.288896] inet6_sendmsg (net/ipv6/af_inet6.c:661)
[ 991.292466] __sock_sendmsg (net/socket.c:717)
[ 991.296126] __sys_sendto (net/socket.c:?)
[ 991.299785] __x64_sys_sendto (net/socket.c:2235 net/socket.c:2231
net/socket.c:2231)
[ 991.303622] x64_sys_call (arch/x86/entry/syscall_64.c:41)
[ 991.307462] do_syscall_64 (arch/x86/entry/syscall_64.c:?)
[ 991.311128] ? irqentry_exit (kernel/entry/common.c:210)
[ 991.314881] ? exc_page_fault (arch/x86/mm/fault.c:1536)
[ 991.318720] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 991.323762] RIP: 0033:0x7f41e814b687
[ 991.327352] Code: 48 89 fa 4c 89 df e8 58 b3 00 00 8b 93 08 03 00 00
59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10
0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff
ff
All code
========
0: 48 89 fa mov %rdi,%rdx
3: 4c 89 df mov %r11,%rdi
6: e8 58 b3 00 00 call 0xb363
b: 8b 93 08 03 00 00 mov 0x308(%rbx),%edx
11: 59 pop %rcx
12: 5e pop %rsi
13: 48 83 f8 fc cmp $0xfffffffffffffffc,%rax
17: 74 1a je 0x33
19: 5b pop %rbx
1a: c3 ret
1b: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
22: 00
23: 48 8b 44 24 10 mov 0x10(%rsp),%rax
28: 0f 05 syscall
2a:* 5b pop %rbx <-- trapping instruction
2b: c3 ret
2c: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
33: 83 e2 39 and $0x39,%edx
36: 83 fa 08 cmp $0x8,%edx
39: 75 de jne 0x19
3b: e8 23 ff ff ff call 0xffffffffffffff63
Code starting with the faulting instruction
===========================================
0: 5b pop %rbx
1: c3 ret
2: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
9: 83 e2 39 and $0x39,%edx
c: 83 fa 08 cmp $0x8,%edx
f: 75 de jne 0xffffffffffffffef
11: e8 23 ff ff ff call 0xffffffffffffff39
[ 991.346124] RSP: 002b:00007ffdd843ba50 EFLAGS: 00000202 ORIG_RAX:
000000000000002c
[ 991.353680] RAX: ffffffffffffffda RBX: 00007f41e80b9740 RCX: 00007f41e814b687
[ 991.360806] RDX: 000000000000f180 RSI: 000056251f1fd100 RDI: 0000000000000005
[ 991.367931] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[ 991.375063] R10: 0000000004000000 R11: 0000000000000202 R12: 0000000000000000
[ 991.382193] R13: 000056251f1fb080 R14: 000001a670e438d8 R15: 0000000000000005
[ 991.389357] </TASK>
[ 991.391571] Modules linked in: mptcp_diag tcp_diag inet_diag
xt_conntrack xfrm_user ipip bridge stp llc geneve vxlan act_csum
act_pedit openvswitch nsh nf_nat nf_conntrack nf_defrag_ipv6
nf_defrag_ipv4 psample cls_flower sch_prio xt_mark nft_compat
nf_tables sch_ingress act_mirred cls_basic sch_fq_codel vrf pktgen
macvtap macvlan tap x86_pkg_temp_thermal ip_tables x_tables [last
unloaded: test_bpf]
[ 991.426812] CR2: 0000000000000008
[ 991.430121] ---[ end trace 0000000000000000 ]---
[ 991.434733] RIP: 0010:zerocopy_fill_skb_from_iter
(include/linux/page-flags.h:284)
[ 991.440477] Code: 4d 85 c0 0f 84 04 01 00 00 44 39 c7 41 0f 4d f8 4c
63 de 4a 8b 54 dc 30 49 89 d6 4d 29 ce 49 c1 fe 06 49 d3 ee 4d 85 f6
74 24 <48> 8b 4a 08 f6 c1 01 0f 85 cb 00 00 00 0f 1f 44 00 00 31 c9 48
f7
All code
========
0: 4d 85 c0 test %r8,%r8
3: 0f 84 04 01 00 00 je 0x10d
9: 44 39 c7 cmp %r8d,%edi
c: 41 0f 4d f8 cmovge %r8d,%edi
10: 4c 63 de movslq %esi,%r11
13: 4a 8b 54 dc 30 mov 0x30(%rsp,%r11,8),%rdx
18: 49 89 d6 mov %rdx,%r14
1b: 4d 29 ce sub %r9,%r14
1e: 49 c1 fe 06 sar $0x6,%r14
22: 49 d3 ee shr %cl,%r14
25: 4d 85 f6 test %r14,%r14
28: 74 24 je 0x4e
2a:* 48 8b 4a 08 mov 0x8(%rdx),%rcx <-- trapping instruction
2e: f6 c1 01 test $0x1,%cl
31: 0f 85 cb 00 00 00 jne 0x102
37: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
3c: 31 c9 xor %ecx,%ecx
3e: 48 rex.W
3f: f7 .byte 0xf7
Code starting with the faulting instruction
===========================================
0: 48 8b 4a 08 mov 0x8(%rdx),%rcx
4: f6 c1 01 test $0x1,%cl
7: 0f 85 cb 00 00 00 jne 0xd8
d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
12: 31 c9 xor %ecx,%ecx
14: 48 rex.W
15: f7 .byte 0xf7
[ 991.459215] RSP: 0018:ffffb11281d0ba90 EFLAGS: 00010202
[ 991.464434] RAX: ffffe14ec4208000 RBX: 0000000000005000 RCX: 0000000000000009
[ 991.471557] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000001000
[ 991.478681] RBP: ffffb11281d0bb88 R08: 00000000000020ff R09: ffffe14ec4208000
[ 991.485807] R10: 0000000000000005 R11: 0000000000000006 R12: ffff96b4825f4200
[ 991.492930] R13: 0000000000000001 R14: 000000003d6277bf R15: 0000000000000000
[ 991.500054] FS: 00007f41e80b9740(0000) GS:ffff96b83bc1b000(0000)
knlGS:0000000000000000
[ 991.508132] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 991.513870] CR2: 0000000000000008 CR3: 0000000106c42003 CR4: 00000000003706f0
[ 991.520994] note: udpgso_bench_tx[64842] exited with irqs disabled
## Source
* Kernel version: 6.17.0-rc4
* Git tree:
https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
* Git describe: next-20250905
* Git commit: be5d4872e528796df9d7425f2bd9b3893eb3a42c
* Architectures: x86_64
* Toolchains: clang-nightly
* Kconfigs: defconfig+selftests/*/config
## Build
* Test log: https://qa-reports.linaro.org/api/testruns/29777495/log_file/
* LAVA test log: https://lkft.validation.linaro.org/scheduler/job/8434053#L16943
* Test details:
https://regressions.linaro.org/lkft/linux-next-master/next-20250905/log-parser-test/oops-oops-oops-smp-pti/
* Test plan:
https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/32GkXBGNRNDEj5d64zd73eXhXQC
* Build link:
https://storage.tuxsuite.com/public/linaro/lkft/builds/32GkU7mdlpISpPeeeEwIfAJuzqG/
* Kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/32GkU7mdlpISpPeeeEwIfAJuzqG/config
--
Linaro LKFT
https://lkft.linaro.org
