syzbot


WARNING in maybe_exit_scc

Status: upstream: reported C repro on 2025/09/15 18:28
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+3afc814e8df1af64b653@syzkaller.appspotmail.com
Fix commit: a3c73d629ea1 bpf: dont report verifier bug for missing bpf_scc_visit on speculative path
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-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 ci-upstream-gce-arm64]
First crash: 33d, last: 17d
Cause bisection: introduced by (bisect log) :
commit d6f1c85f22534d2d9fea9b32645da19c91ebe7d2
Author: Luis Gerhorst <luis.gerhorst@fau.de>
Date: Tue Jun 3 21:24:28 2025 +0000

  bpf: Fall back to nospec for Spectre v1

Crash: WARNING in do_check_common (log)
Repro: C syz .config
  
Duplicate bugs (1)
duplicates (1):
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
WARNING in do_check (2) bpf -1 C done 40 17d 32d 0/29 closed as dup on 2025/09/22 11:17
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [bpf?] WARNING in maybe_exit_scc 4 (6) 2025/09/29 07:57
[PATCH bpf-next v1 1/2] bpf: dont report verifier bug for missing bpf_scc_visit on speculative path 6 (6) 2025/09/17 18:30

Sample crash report:
------------[ cut here ]------------
verifier bug: scc exit: no visit info for call chain (1)(1)
WARNING: CPU: 1 PID: 6013 at kernel/bpf/verifier.c:1949 maybe_exit_scc+0x768/0x8d0 kernel/bpf/verifier.c:1949
Modules linked in:
CPU: 1 UID: 0 PID: 6013 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:maybe_exit_scc+0x768/0x8d0 kernel/bpf/verifier.c:1949
Code: ff ff e8 cb 8e e7 ff c6 05 0a b5 bf 0e 01 90 48 89 ee 48 89 df e8 f8 41 fb ff 48 c7 c7 a0 9b b5 8b 48 89 c6 e8 59 33 a6 ff 90 <0f> 0b 90 90 e9 4e ff ff ff e8 0a ee 4d 00 e9 7f f9 ff ff 4c 8b 4c
RSP: 0018:ffffc900041bf500 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888079840000 RCX: ffffffff817a4388
RDX: ffff88807d3f8000 RSI: ffffffff817a4395 RDI: 0000000000000001
RBP: ffff888079846328 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 1ffff92000837ea7
R13: 0000000000000000 R14: ffff88805cf87400 R15: dffffc0000000000
FS:  000055557c9b5500(0000) GS:ffff8881247b2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557c9b5808 CR3: 0000000073b4d000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 update_branch_counts kernel/bpf/verifier.c:2040 [inline]
 do_check kernel/bpf/verifier.c:20135 [inline]
 do_check_common+0x20cc/0xb410 kernel/bpf/verifier.c:23264
 do_check_main kernel/bpf/verifier.c:23347 [inline]
 bpf_check+0x869f/0xc670 kernel/bpf/verifier.c:24707
 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/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd1d078eba9
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:00007ffee0400aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fd1d09d5fa0 RCX: 00007fd1d078eba9
RDX: 0000000000000048 RSI: 00002000000017c0 RDI: 0000000000000005
RBP: 00007fd1d0811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd1d09d5fa0 R14: 00007fd1d09d5fa0 R15: 0000000000000003
 </TASK>

Crashes (59):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/15 13:57 upstream f83ec76bf285 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 13:26 upstream f83ec76bf285 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 13:08 upstream f83ec76bf285 e2beed91 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/10/01 05:38 upstream 30d4efb2f5a5 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/25 12:39 upstream bf40f4b87761 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/25 11:23 upstream 4ea5af085908 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/25 11:23 upstream 4ea5af085908 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:19 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:19 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:15 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:14 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:14 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 17:14 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in maybe_exit_scc
2025/09/15 12:55 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 12:54 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 12:54 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 12:54 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 12:53 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/15 12:53 upstream f83ec76bf285 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in maybe_exit_scc
2025/09/25 11:22 upstream bf40f4b87761 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/25 11:22 upstream bf40f4b87761 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/25 11:22 upstream bf40f4b87761 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:58 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:58 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:56 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:56 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:55 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:55 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:54 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 12:54 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in maybe_exit_scc
2025/09/15 13:51 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:51 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:51 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:51 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:50 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:50 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:50 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:50 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:49 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:48 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:48 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:48 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
2025/09/15 13:48 upstream f83ec76bf285 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in maybe_exit_scc
* Struck through repros no longer work on HEAD.