syzbot


WARNING: locking bug in __pcpu_freelist_pop

Status: upstream: reported on 2024/06/14 08:30
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+520605fec365a2b46c6f@syzkaller.appspotmail.com
First crash: 29d, last: 22d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] WARNING: locking bug in __pcpu_freelist_pop 0 (1) 2024/06/14 08:30

Sample crash report:
------------[ cut here ]------------
Looking for class "head->lock" with key __key.1, but found a different class "&head->lock" with the same key
WARNING: CPU: 1 PID: 6244 at kernel/locking/lockdep.c:932 look_up_lock_class+0x133/0x140 kernel/locking/lockdep.c:932
Modules linked in:
CPU: 1 PID: 6244 Comm: syz-executor.2 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:look_up_lock_class+0x133/0x140 kernel/locking/lockdep.c:932
Code: c7 c7 20 b9 2c 8b e8 cc 53 74 f6 90 0f 0b 90 90 90 31 db eb be c6 05 f5 86 ef 04 01 90 48 c7 c7 40 bc 2c 8b e8 ae 53 74 f6 90 <0f> 0b 90 90 e9 62 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900078c7688 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffffffff9425bfd0 RCX: ffffc90003119000
RDX: 0000000000040000 RSI: ffffffff81511296 RDI: 0000000000000001
RBP: ffffffff94ae7da0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 20676e696b6f6f4c R12: ffffe8ffad35c580
R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff94ad8be0
FS:  0000000000000000(0000) GS:ffff88802c100000(0063) knlGS:00000000f5efdb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020504000 CR3: 00000000571fa000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 register_lock_class+0xb1/0x1230 kernel/locking/lockdep.c:1284
 __lock_acquire+0x111/0x3b30 kernel/locking/lockdep.c:5014
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 ___pcpu_freelist_pop kernel/bpf/percpu_freelist.c:131 [inline]
 __pcpu_freelist_pop+0x18b/0x9f0 kernel/bpf/percpu_freelist.c:188
 pcpu_freelist_pop+0x72/0xe0 kernel/bpf/percpu_freelist.c:197
 alloc_extra_elems kernel/bpf/hashtab.c:402 [inline]
 htab_map_alloc+0xbcc/0x17b0 kernel/bpf/hashtab.c:584
 map_create+0x57b/0x1c60 kernel/bpf/syscall.c:1333
 __sys_bpf+0xb0b/0x5830 kernel/bpf/syscall.c:5670
 __do_sys_bpf kernel/bpf/syscall.c:5795 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5793 [inline]
 __ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5793
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf732c579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5efd5ac EFLAGS: 00000292 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000020000340
RDX: 0000000000000048 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/20 13:53 upstream 2ccbdf43d5e7 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING: locking bug in __pcpu_freelist_pop
2024/06/14 03:15 upstream 2ccbdf43d5e7 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING: locking bug in __pcpu_freelist_pop
2024/06/13 23:46 upstream 2ccbdf43d5e7 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING: locking bug in __pcpu_freelist_pop
* Struck through repros no longer work on HEAD.