syzbot


possible deadlock in __stack_map_get

Status: upstream: reported C repro on 2024/04/18 20:00
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+dddd99ae26c656485d89@syzkaller.appspotmail.com
First crash: 16d, last: 3d15h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] possible deadlock in __stack_map_get 2 (5) 2024/04/19 14:12
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in __stack_map_get origin:upstream C 2 8d03h 18d 0/3 upstream: reported C repro on 2024/04/12 22:39
Last patch testing requests (2)
Created Duration User Patch Repo Result
2024/04/19 11:03 1h35m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git f99c5f563c17 OK log
2024/04/18 23:09 2h20m hdanton@sina.com patch https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git f99c5f563c17 report log

Sample crash report:
============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-05271-gf99c5f563c17 #0 Not tainted
--------------------------------------------
syz-executor224/5098 is trying to acquire lock:
ffff888021ef61d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140

but task is already holding lock:
ffff888021ef51d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&qs->lock);
  lock(&qs->lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz-executor224/5098:
 #0: ffffffff8e200c68 (pcpu_alloc_mutex){+.+.}-{3:3}, at: pcpu_alloc+0x27b/0x1670 mm/percpu.c:1769
 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #1: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420
 #2: ffff888021ef51d8 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140
 #3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #3: ffffffff8e131920 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420

stack backtrace:
CPU: 0 PID: 5098 Comm: syz-executor224 Not tainted 6.8.0-syzkaller-05271-gf99c5f563c17 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain+0x15c1/0x58e0 kernel/locking/lockdep.c:3856
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140
 bpf_prog_7a16b54e5ee857f9+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0xf6/0x120 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x939/0xc60 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline]
 queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162
 __stack_map_get+0x14b/0x4b0 kernel/bpf/queue_stack_maps.c:140
 bpf_prog_7a16b54e5ee857f9+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
 __bpf_prog_run include/linux/filter.h:657 [inline]
 bpf_prog_run include/linux/filter.h:664 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
 bpf_trace_run2+0x204/0x420 kernel/trace/bpf_trace.c:2420
 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0xd7/0x100 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:617 [inline]
 __mutex_lock+0x2e5/0xd70 kernel/locking/mutex.c:752
 pcpu_alloc+0x27b/0x1670 mm/percpu.c:1769
 bpf_prog_alloc_no_stats+0x10b/0x4a0 kernel/bpf/core.c:112
 bpf_prog_alloc+0x3b/0x1b0 kernel/bpf/core.c:144
 bpf_prog_load+0x7f7/0x20f0 kernel/bpf/syscall.c:2805
 __sys_bpf+0x4ee/0x810 kernel/bpf/syscall.c:5631
 __do_sys_bpf kernel/bpf/syscall.c:5738 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5736 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5736
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fb8f4667f69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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:00007ffc6855faf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb8f4667f69
RDX: 0000000000000090 RSI: 00000000200000c0 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/15 11:26 net f99c5f563c17 c8349e48 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __stack_map_get
2024/04/14 19:51 bpf 443574b03387 c8349e48 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce possible deadlock in __stack_map_get
2024/04/25 10:15 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in __stack_map_get
2024/04/25 03:19 upstream e88c4cfcb7b8 8bdc0f22 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in __stack_map_get
2024/04/27 23:21 net b2ff42c6d3ab 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce possible deadlock in __stack_map_get
2024/04/20 11:09 bpf 443574b03387 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce possible deadlock in __stack_map_get
* Struck through repros no longer work on HEAD.