syzbot


BUG: corrupted list in flow_block_cb_setup_simple

Status: upstream: reported C repro on 2025/09/12 07:06
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+5a66db916cdde0dbcc1c@syzkaller.appspotmail.com
First crash: 21h42m, last: 11h29m
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [net?] BUG: corrupted list in flow_block_cb_setup_simple 1 (3) 2025/09/12 12:45
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: corrupted list in flow_block_cb_setup_simple 8 1 45d 45d 0/3 upstream: reported on 2025/07/28 23:54
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/09/12 09:30 3h13m hdanton@sina.com patch upstream OK log

Sample crash report:
 non-slab/vmalloc memory
list_del corruption. prev->next should be ffff888031333e00, but was ffffffff8edac9a0. (prev=ffffffff8edac9a0)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:64!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6309 Comm: syz.3.187 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__list_del_entry_valid_or_report+0x15a/0x190 lib/list_debug.c:62
Code: e8 4b a5 31 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 1c 9d 52 fd 49 8b 17 48 c7 c7 a0 40 e3 8b 48 89 de 4c 89 f9 e8 07 0b 57 fc 90 <0f> 0b 4c 89 f7 e8 1c a5 31 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 ed
RSP: 0018:ffffc90002e26760 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888031333e00 RCX: 1da0b3c0fbb48400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff920005c4d3e R08: ffffc90002e26487 R09: 1ffff920005c4c90
R10: dffffc0000000000 R11: fffff520005c4c91 R12: 1ffffffff1db5934
R13: dffffc0000000000 R14: ffffffff8edac9a0 R15: ffffffff8edac9a0
FS:  000055555b81d500(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555565514808 CR3: 0000000068c1a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del include/linux/list.h:229 [inline]
 flow_block_cb_setup_simple+0x62d/0x740 net/core/flow_offload.c:369
 nft_block_offload_cmd net/netfilter/nf_tables_offload.c:397 [inline]
 nft_chain_offload_cmd+0x290/0x660 net/netfilter/nf_tables_offload.c:451
 nft_flow_block_chain net/netfilter/nf_tables_offload.c:471 [inline]
 nft_flow_offload_chain net/netfilter/nf_tables_offload.c:513 [inline]
 nft_flow_rule_offload_commit+0x40d/0x1b60 net/netfilter/nf_tables_offload.c:592
 nf_tables_commit+0x675/0x8700 net/netfilter/nf_tables_api.c:10933
 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:574 [inline]
 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:647 [inline]
 nfnetlink_rcv+0x1a4e/0x2520 net/netfilter/nfnetlink.c:665
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0bd1b8eba9
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:00007ffddc0ed9e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0bd1dd5fa0 RCX: 00007f0bd1b8eba9
RDX: 000000000000c050 RSI: 0000200000000cc0 RDI: 0000000000000003
RBP: 00007f0bd1c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0bd1dd5fa0 R14: 00007f0bd1dd5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x15a/0x190 lib/list_debug.c:62
Code: e8 4b a5 31 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 1c 9d 52 fd 49 8b 17 48 c7 c7 a0 40 e3 8b 48 89 de 4c 89 f9 e8 07 0b 57 fc 90 <0f> 0b 4c 89 f7 e8 1c a5 31 fd 43 80 3c 2c 00 74 08 4c 89 ff e8 ed
RSP: 0018:ffffc90002e26760 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff888031333e00 RCX: 1da0b3c0fbb48400
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff920005c4d3e R08: ffffc90002e26487 R09: 1ffff920005c4c90
R10: dffffc0000000000 R11: fffff520005c4c91 R12: 1ffffffff1db5934
R13: dffffc0000000000 R14: ffffffff8edac9a0 R15: ffffffff8edac9a0
FS:  000055555b81d500(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000380 CR3: 0000000068c1a000 CR4: 00000000003526f0

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/12 07:54 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
2025/09/12 06:27 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
2025/09/12 05:00 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
2025/09/12 03:29 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
2025/09/11 23:17 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
2025/09/12 00:57 bpf e59a039119c3 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce KASAN: slab-use-after-free Read in flow_block_cb_setup_simple
2025/09/11 21:41 bpf e59a039119c3 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: corrupted list in flow_block_cb_setup_simple
* Struck through repros no longer work on HEAD.