syzbot


possible deadlock in __queue_map_get

Status: upstream: reported C repro on 2024/04/08 00:56
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+74e452172ac5a1e20d64@syzkaller.appspotmail.com
First crash: 25d, last: 14d
Bug presence (1)
Date Name Commit Repro Result
2024/04/29 upstream (ToT) b947cc5bf6d7 C [report] possible deadlock in __queue_map_get
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in __queue_map_get bpf C 46 7h45m 20d 0/26 upstream: reported C repro on 2024/04/13 05:14

Sample crash report:
============================================
WARNING: possible recursive locking detected
6.1.86-syzkaller #0 Not tainted
--------------------------------------------
syz-executor128/3612 is trying to acquire lock:
ffff88807b427218 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x146/0x4b0 kernel/bpf/queue_stack_maps.c:109

but task is already holding lock:
ffff88807b425218 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x146/0x4b0 kernel/bpf/queue_stack_maps.c:109

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-executor128/3612:
 #0: ffff88807a6a93f8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_cleanup_begin kernel/futex/core.c:1076 [inline]
 #0: ffff88807a6a93f8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_exit_release+0x30/0x1e0 kernel/futex/core.c:1128
 #1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #1: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312
 #2: ffff88807b425218 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x146/0x4b0 kernel/bpf/queue_stack_maps.c:109
 #3: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #3: ffffffff8d12ac40 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2312

stack backtrace:
CPU: 0 PID: 3612 Comm: syz-executor128 Not tainted 6.1.86-syzkaller #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+0x1e3/0x2cb lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2983 [inline]
 check_deadlock kernel/locking/lockdep.c:3026 [inline]
 validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 __queue_map_get+0x146/0x4b0 kernel/bpf/queue_stack_maps.c:109
 bpf_prog_00798911c748094f+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
 bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x14c/0x190 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x269/0x370 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162
 __queue_map_get+0x146/0x4b0 kernel/bpf/queue_stack_maps.c:109
 bpf_prog_00798911c748094f+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:989 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2273 [inline]
 bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x12f/0x170 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:612 [inline]
 __mutex_lock+0x2ed/0xd80 kernel/locking/mutex.c:747
 futex_cleanup_begin kernel/futex/core.c:1076 [inline]
 futex_exit_release+0x30/0x1e0 kernel/futex/core.c:1128
 exit_mm_release+0x16/0x30 kernel/fork.c:1505
 exit_mm+0xa9/0x300 kernel/exit.c:535
 do_exit+0x9f6/0x26a0 kernel/exit.c:856
 do_group_exit+0x202/0x2b0 kernel/exit.c:1019
 __do_sys_exit_group kernel/exit.c:1030 [inline]
 __se_sys_exit_group kernel/exit.c:1028 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7d8826cf79
Code: 90 49 c7 c0 b8 ff ff ff be e7 00 00 00 ba 3c 00 00 00 eb 12 0f 1f 44 00 00 89 d0 0f 05 48 3d 00 f0 ff ff 77 1c f4 89 f0 0f 05 <48> 3d 00 f0 ff ff 76 e7 f7 d8 64 41 89 00 eb df 0f 1f 80 00 00 00
RSP: 002b:00007ffde0ccbd48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7d8826cf79
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f7d882e82b0 R08: ffffffffffffffb8 R09: 00000000000000a0
R10: 00000000000000a0 R11: 0000000000000246 R12: 00007f7d882e82b0
R13: 0000000000000000 R14: 00007f7d882e8d20 R15: 00007f7d8823e120
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/15 02:16 linux-6.1.y cd5d98c0556c c8349e48 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf possible deadlock in __queue_map_get
2024/04/19 00:11 linux-6.1.y 6741e066ec76 af24b050 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf possible deadlock in __queue_map_get
2024/04/15 01:19 linux-6.1.y cd5d98c0556c c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf possible deadlock in __queue_map_get
2024/04/08 00:55 linux-6.1.y 347385861c50 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in __queue_map_get
* Struck through repros no longer work on HEAD.