| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CANn89iKciN019j88sGYpi_Boi7ggJoSnV4gOW=5grp+skkKnBA@mail.gmail.com>
Date: Fri, 5 Sep 2025 05:55:57 -0700
From: Eric Dumazet <edumazet@...gle.com>
To: Naresh Kamboju <naresh.kamboju@...aro.org>, David Hildenbrand <david@...hat.com>
Cc: Netdev <netdev@...r.kernel.org>,
"open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest@...r.kernel.org>, open list <linux-kernel@...r.kernel.org>,
lkft-triage@...ts.linaro.org, Linux Regressions <regressions@...ts.linux.dev>,
"David S. Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
Eric Biggers <ebiggers@...gle.com>, Dan Carpenter <dan.carpenter@...aro.org>,
Arnd Bergmann <arnd@...db.de>, Ben Copeland <benjamin.copeland@...aro.org>,
Anders Roxell <anders.roxell@...aro.org>, Shuah Khan <shuah@...nel.org>,
Willem de Bruijn <willemb@...gle.com>, Pengtao He <hept.hept.hept@...il.com>
Subject: Re: next-20250905: x86_64: udpgso_bench.sh triggers NULL deref in zerocopy_fill_skb_from_iter
On Fri, Sep 5, 2025 at 2:30 AM Naresh Kamboju <naresh.kamboju@...aro.org> wrote:
>
> 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 <lkft@...aro.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
I suspect a bug added in mm/gup.c recently
commit db076b5db550aa34169dceee81d0974c7b2a2482
Author: David Hildenbrand <david@...hat.com>
Date: Mon Sep 1 17:03:40 2025 +0200
mm/gup: remove record_subpages()
We can just cleanup the code by calculating the #refs earlier, so we can
just inline what remains of record_subpages().
Calculate the number of references/pages ahead of times, and record them
only once all our tests passed.
Link: https://lkml.kernel.org/r/20250901150359.867252-20-david@redhat.com
Signed-off-by: David Hildenbrand <david@...hat.com>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Powered by blists - more mailing lists