syzbot


WARNING in convert_ctx_accesses

Status: upstream: reported C repro on 2025/07/31 03:19
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+ccac90e482b2a81d74aa@syzkaller.appspotmail.com
Fix commit: ead3d7b2b6af bpf: Check flow_dissector ctx accesses are aligned
Patched on: [ci-qemu-gce-upstream-auto 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-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-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-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm]
First crash: 29d, last: 7d14h
Cause bisection: introduced by (bisect log) :
commit 0df1a55afa832f463f9ad68ddc5de92230f1bc8a
Author: Paul Chaignon <paul.chaignon@gmail.com>
Date: Tue Jul 1 18:36:15 2025 +0000

  bpf: Warn on internal verifier errors

Crash: WARNING in convert_ctx_accesses (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH bpf 1/4] bpf: Check flow_dissector ctx accesses are aligned 3 (3) 2025/08/01 16:04
[syzbot] [bpf?] WARNING in convert_ctx_accesses 1 (3) 2025/07/31 13:53

Sample crash report:
------------[ cut here ]------------
verifier bug: error during ctx access conversion(1)
WARNING: CPU: 0 PID: 5822 at kernel/bpf/verifier.c:21448 convert_ctx_accesses+0x2045/0x2920 kernel/bpf/verifier.c:21448
Modules linked in:
CPU: 0 UID: 0 PID: 5822 Comm: syz-executor130 Not tainted 6.16.0-syzkaller-06699-ge8d780dcd957 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:convert_ctx_accesses+0x2045/0x2920 kernel/bpf/verifier.c:21448
Code: c7 c6 a0 95 b5 8b e8 ea a5 07 00 e9 a4 f9 ff ff e8 50 6c e8 ff c6 05 16 03 bd 0e 01 90 48 c7 c7 00 96 b5 8b e8 6c 02 a7 ff 90 <0f> 0b 90 90 e9 f1 fe ff ff e8 2d 6c e8 ff 0f b6 1d f6 02 bd 0e 31
RSP: 0018:ffffc90003dcf6e8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a3658
RDX: ffff8880775dc880 RSI: ffffffff817a3665 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000
R13: ffffc90000ace048 R14: 0000000000000004 R15: ffff888023798000
FS:  0000555582c6c380(0000) GS:ffff88812471e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561e04e07000 CR3: 0000000071c4c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 bpf_check+0x5960/0xc600 kernel/bpf/verifier.c:24736
 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2972
 __sys_bpf+0x4a3f/0x4de0 kernel/bpf/syscall.c:6022
 __do_sys_bpf kernel/bpf/syscall.c:6132 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6130 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6130
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75a63f53a9
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffeb40793f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffeb40795d8 RCX: 00007f75a63f53a9
RDX: 0000000000000048 RSI: 00002000000054c0 RDI: 0000000000000005
RBP: 00007f75a6468610 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffeb40795c8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (80):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/31 01:33 upstream e8d780dcd957 f8f2b4da .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/31 01:10 upstream e8d780dcd957 f8f2b4da .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/31 00:48 upstream e8d780dcd957 f8f2b4da .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/08/02 03:02 upstream 89748acdf226 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/31 00:41 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in convert_ctx_accesses
2025/07/30 23:48 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/30 23:48 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/30 22:42 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/30 21:07 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/30 21:07 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in convert_ctx_accesses
2025/07/30 20:40 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in convert_ctx_accesses
2025/07/30 20:40 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in convert_ctx_accesses
2025/07/31 01:27 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/31 01:26 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 23:43 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 23:42 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 23:38 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 23:14 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 22:11 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 22:06 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/07/30 22:05 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in convert_ctx_accesses
2025/08/21 22:49 upstream 32b7144f806e 3e79b825 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-compat WARNING in convert_ctx_accesses
2025/08/14 08:04 upstream 3a4a0367c9f4 22ec1469 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/08/13 05:12 upstream 0e39a731820a 22ec1469 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/08/07 21:47 upstream 6e64f4580381 04cffc22 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64 WARNING in convert_ctx_accesses
2025/08/05 08:13 upstream 35a813e010b9 f5bcc8dc .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/08/02 15:59 upstream 89748acdf226 7368264b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/08/01 23:48 upstream 89748acdf226 40127d41 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/08/01 23:42 upstream 89748acdf226 40127d41 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/08/01 12:14 upstream d6084bb815c4 0c075d67 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm64-mte WARNING in convert_ctx_accesses
2025/07/31 03:11 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 01:23 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 01:21 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 00:43 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 00:41 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 00:40 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/31 00:34 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:34 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:29 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:25 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:18 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:16 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:07 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:05 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 21:04 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:54 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:54 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:52 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:52 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:35 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:35 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:33 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
2025/07/30 20:11 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in convert_ctx_accesses
* Struck through repros no longer work on HEAD.