syzbot


BUG: corrupted list in nsim_bpf_verifier_prep (2)

Status: upstream: reported on 2025/09/03 21:59
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+530656d6f93f3af256f3@syzkaller.appspotmail.com
First crash: 9d22h, last: 1d03h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] BUG: corrupted list in nsim_bpf_verifier_prep (2) 0 (1) 2025/09/03 21:59
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: corrupted list in nsim_bpf_verifier_prep net 8 1 637d 637d 0/29 closed as invalid on 2024/02/12 15:10

Sample crash report:
 slab kmalloc-2k start ffff888029814000 pointer offset 960 size 2048
list_add corruption. next->prev should be prev (ffff8880298143c0), but was ffff888054fb97a8. (next=ffff8880298143c0).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:29!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 13094 Comm: syz.7.1998 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__list_add_valid_or_report+0xec/0x190 lib/list_debug.c:29
Code: 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 a5 00 00 00 48 8b 55 08 48 89 e9 48 c7 c7 00 2f 16 8c e8 a5 4c af fc 90 <0f> 0b 48 89 f7 48 89 34 24 e8 96 8c 13 fd 48 8b 34 24 48 b8 00 00
RSP: 0018:ffffc900044c7718 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff8880559d4500 RCX: ffffffff819a4e09
RDX: 0000000000000000 RSI: ffffffff819acca6 RDI: 0000000000000005
RBP: ffff8880298143c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff8880559d4528
R13: ffff8880298143c8 R14: ffff8880298143c0 R15: ffffc900028d8038
FS:  00007effeccb06c0(0000) GS:ffff8880d66b5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007effecc8ef98 CR3: 0000000036c43000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 000000000000003b DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add_tail include/linux/list.h:183 [inline]
 nsim_bpf_create_prog drivers/net/netdevsim/bpf.c:247 [inline]
 nsim_bpf_verifier_prep+0x37e/0x650 drivers/net/netdevsim/bpf.c:262
 bpf_prog_offload_verifier_prep+0xe1/0x180 kernel/bpf/offload.c:305
 bpf_check+0x61bb/0xc670 kernel/bpf/verifier.c:24678
 bpf_prog_load+0xe41/0x2490 kernel/bpf/syscall.c:2979
 __sys_bpf+0x4a3f/0x4de0 kernel/bpf/syscall.c:6029
 __do_sys_bpf kernel/bpf/syscall.c:6139 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6137 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6137
 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: 0033:0x7effebd8ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007effeccb0038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007effebfc6090 RCX: 00007effebd8ebe9
RDX: 0000000000000080 RSI: 0000200000001800 RDI: 0000000000000005
RBP: 00007effebe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007effebfc6128 R14: 00007effebfc6090 R15: 00007ffd23160258
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report+0xec/0x190 lib/list_debug.c:29
Code: 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 a5 00 00 00 48 8b 55 08 48 89 e9 48 c7 c7 00 2f 16 8c e8 a5 4c af fc 90 <0f> 0b 48 89 f7 48 89 34 24 e8 96 8c 13 fd 48 8b 34 24 48 b8 00 00
RSP: 0018:ffffc900044c7718 EFLAGS: 00010282
RAX: 0000000000000075 RBX: ffff8880559d4500 RCX: ffffffff819a4e09
RDX: 0000000000000000 RSI: ffffffff819acca6 RDI: 0000000000000005
RBP: ffff8880298143c0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff8880559d4528
R13: ffff8880298143c8 R14: ffff8880298143c0 R15: ffffc900028d8038
FS:  00007effeccb06c0(0000) GS:ffff8880d69b5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32023ffc CR3: 0000000036c43000 CR4: 0000000000352ef0
DR0: 000000000000000a DR1: 0000000000000002 DR2: 0000000000000003
DR3: 0000000080000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/08 17:01 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream BUG: corrupted list in nsim_bpf_verifier_prep
2025/08/30 21:42 net 788bc43d8330 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce BUG: corrupted list in nsim_bpf_verifier_prep
* Struck through repros no longer work on HEAD.