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* [syzbot] [net?] [bpf?] possible deadlock in __lock_task_sighand (2)
@ 2024-03-18 21:47 syzbot
  2024-05-11  5:39 ` [syzbot] [bpf?] [net?] " syzbot
  0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2024-03-18 21:47 UTC (permalink / raw)
  To: andrii, ast, bpf, daniel, davem, edumazet, jakub, john.fastabend,
	kuba, linux-kernel, netdev, pabeni, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11725ac9180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
dashboard link: https://syzkaller.appspot.com/bug?extid=34267210261c2cbba2da
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f6c04726a2ae/disk-fe46a7dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/09c26ce901ea/vmlinux-fe46a7dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/134acf7f5322/bzImage-fe46a7dd.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+34267210261c2cbba2da@syzkaller.appspotmail.com

=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
-----------------------------------------------------
syz-fuzzer/5356 [HC0[0]:SC0[2]:HE0:SE0] is trying to acquire:
ffff888092ee3020 (&htab->buckets[i].lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888092ee3020 (&htab->buckets[i].lock){+.-.}-{2:2}, at: sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939

and this task is already holding:
ffff888015f2d358 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
ffff888015f2d358 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699
which would create a new lock dependency:
 (&sighand->siglock){-.-.}-{2:2} -> (&htab->buckets[i].lock){+.-.}-{2:2}

but this new dependency connects a HARDIRQ-irq-safe lock:
 (&sighand->siglock){-.-.}-{2:2}

... which became HARDIRQ-irq-safe at:
  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
  __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414
  lock_task_sighand include/linux/sched/signal.h:746 [inline]
  send_sigqueue+0x25d/0x760 kernel/signal.c:1997
  posix_timer_event kernel/time/posix-timers.c:298 [inline]
  posix_timer_fn+0x18a/0x3a0 kernel/time/posix-timers.c:324
  __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
  __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1756
  hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
  __sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
  sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
  __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
  _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
  spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
  unlock_timer kernel/time/posix-timers.c:128 [inline]
  do_timer_settime+0x2db/0x340 kernel/time/posix-timers.c:934
  __do_sys_timer_settime kernel/time/posix-timers.c:954 [inline]
  __se_sys_timer_settime kernel/time/posix-timers.c:940 [inline]
  __x64_sys_timer_settime+0x19e/0x240 kernel/time/posix-timers.c:940
  do_syscall_64+0xfb/0x240
  entry_SYSCALL_64_after_hwframe+0x6d/0x75

to a HARDIRQ-irq-unsafe lock:
 (&htab->buckets[i].lock){+.-.}-{2:2}

... which became HARDIRQ-irq-unsafe at:
...
  lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
  __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
  _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
  spin_lock_bh include/linux/spinlock.h:356 [inline]
  sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1007
  sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
  map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
  __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
  __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

other info that might help us debug this:

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&htab->buckets[i].lock);
                               local_irq_disable();
                               lock(&sighand->siglock);
                               lock(&htab->buckets[i].lock);
  <Interrupt>
    lock(&sighand->siglock);

 *** DEADLOCK ***

2 locks held by syz-fuzzer/5356:
 #0: ffff888015f2d358 (&sighand->siglock){-.-.}-{2:2}, at: spin_lock_irq include/linux/spinlock.h:376 [inline]
 #0: ffff888015f2d358 (&sighand->siglock){-.-.}-{2:2}, at: get_signal+0x247/0x1850 kernel/signal.c:2699
 #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #1: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x14a/0x460 kernel/trace/bpf_trace.c:2421

the dependencies between HARDIRQ-irq-safe lock and the holding lock:
-> (&sighand->siglock){-.-.}-{2:2} {
   IN-HARDIRQ-W at:
                    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
                    __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414
                    lock_task_sighand include/linux/sched/signal.h:746 [inline]
                    send_sigqueue+0x25d/0x760 kernel/signal.c:1997
                    posix_timer_event kernel/time/posix-timers.c:298 [inline]
                    posix_timer_fn+0x18a/0x3a0 kernel/time/posix-timers.c:324
                    __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
                    __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1756
                    hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
                    local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
                    __sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049
                    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
                    sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
                    __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
                    _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
                    spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
                    unlock_timer kernel/time/posix-timers.c:128 [inline]
                    do_timer_settime+0x2db/0x340 kernel/time/posix-timers.c:934
                    __do_sys_timer_settime kernel/time/posix-timers.c:954 [inline]
                    __se_sys_timer_settime kernel/time/posix-timers.c:940 [inline]
                    __x64_sys_timer_settime+0x19e/0x240 kernel/time/posix-timers.c:940
                    do_syscall_64+0xfb/0x240
                    entry_SYSCALL_64_after_hwframe+0x6d/0x75
   IN-SOFTIRQ-W at:
                    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
                    __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414
                    lock_task_sighand include/linux/sched/signal.h:746 [inline]
                    send_sigqueue+0x25d/0x760 kernel/signal.c:1997
                    posix_timer_event kernel/time/posix-timers.c:298 [inline]
                    posix_timer_fn+0x18a/0x3a0 kernel/time/posix-timers.c:324
                    __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
                    __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1756
                    hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818
                    local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline]
                    __sysvec_apic_timer_interrupt+0x107/0x3a0 arch/x86/kernel/apic/apic.c:1049
                    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
                    sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1043
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
                    check_kcov_mode kernel/kcov.c:173 [inline]
                    __sanitizer_cov_trace_pc+0x2f/0x70 kernel/kcov.c:207
                    stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
                    deref_stack_reg+0xd5/0x260 arch/x86/kernel/unwind_orc.c:403
                    unwind_next_frame+0x1ab8/0x2a00 arch/x86/kernel/unwind_orc.c:648
                    arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25
                    stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
                    kasan_save_stack mm/kasan/common.c:47 [inline]
                    kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
                    unpoison_slab_object mm/kasan/common.c:312 [inline]
                    __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
                    kasan_slab_alloc include/linux/kasan.h:201 [inline]
                    slab_post_alloc_hook mm/slub.c:3798 [inline]
                    slab_alloc_node mm/slub.c:3845 [inline]
                    kmem_cache_alloc_node+0x194/0x380 mm/slub.c:3888
                    __alloc_skb+0x1c3/0x440 net/core/skbuff.c:658
                    __netdev_alloc_skb+0x105/0x560 net/core/skbuff.c:732
                    netdev_alloc_skb include/linux/skbuff.h:3306 [inline]
                    dev_alloc_skb include/linux/skbuff.h:3319 [inline]
                    __ieee80211_beacon_get+0x998/0x15c0 net/mac80211/tx.c:5466
                    ieee80211_beacon_get_tim+0xb4/0x320 net/mac80211/tx.c:5588
                    ieee80211_beacon_get include/net/mac80211.h:5552 [inline]
                    mac80211_hwsim_beacon_tx+0x398/0x7e0 drivers/net/wireless/virtual/mac80211_hwsim.c:2296
                    __iterate_interfaces+0x223/0x4c0 net/mac80211/util.c:772
                    ieee80211_iterate_active_interfaces_atomic+0xd8/0x170 net/mac80211/util.c:808
                    mac80211_hwsim_beacon+0xd4/0x1f0 drivers/net/wireless/virtual/mac80211_hwsim.c:2326
                    __run_hrtimer kernel/time/hrtimer.c:1692 [inline]
                    __hrtimer_run_queues+0x595/0xd00 kernel/time/hrtimer.c:1756
                    hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1773
                    __do_softirq+0x2bc/0x943 kernel/softirq.c:554
                    invoke_softirq kernel/softirq.c:428 [inline]
                    __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
                    irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
                    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
                    sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
                    lock_acquire+0x25b/0x530 kernel/locking/lockdep.c:5758
                    rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
                    rcu_read_lock include/linux/rcupdate.h:750 [inline]
                    batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
                    batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719
                    process_one_work kernel/workqueue.c:3254 [inline]
                    process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
                    worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
                    kthread+0x2f0/0x390 kernel/kthread.c:388
                    ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
                    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
   INITIAL USE at:
                   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                   __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
                   _raw_spin_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:170
                   spin_lock_irq include/linux/spinlock.h:376 [inline]
                   calculate_sigpending+0x4f/0x90 kernel/signal.c:188
                   ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143
                   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 }
 ... key      at: [<ffffffff926a68c0>] sighand_ctor.__key+0x0/0x20

the dependencies between the lock to be acquired
 and HARDIRQ-irq-unsafe lock:
-> (&htab->buckets[i].lock){+.-.}-{2:2} {
   HARDIRQ-ON-W at:
                    lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
                    _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
                    spin_lock_bh include/linux/spinlock.h:356 [inline]
                    sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1007
                    sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
                    map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
                    __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
                    __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
   IN-SOFTIRQ-W at:
                    lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                    __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
                    _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
                    spin_lock_bh include/linux/spinlock.h:356 [inline]
                    sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
                    bpf_prog_2c29ac5cdc6b1842+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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421
                    trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
                    kmem_cache_free+0x23c/0x2b0 mm/slub.c:4343
                    rcu_do_batch kernel/rcu/tree.c:2196 [inline]
                    rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2471
                    __do_softirq+0x2bc/0x943 kernel/softirq.c:554
                    run_ksoftirqd+0xc5/0x130 kernel/softirq.c:924
                    smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
                    kthread+0x2f0/0x390 kernel/kthread.c:388
                    ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
                    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
   INITIAL USE at:
                   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
                   __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
                   _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
                   spin_lock_bh include/linux/spinlock.h:356 [inline]
                   sock_hash_update_common+0x20c/0xa30 net/core/sock_map.c:1007
                   sock_map_update_elem_sys+0x5a4/0x910 net/core/sock_map.c:581
                   map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1641
                   __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5619
                   __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
 }
 ... key      at: [<ffffffff94869300>] sock_hash_alloc.__key+0x0/0x20
 ... acquired at:
   lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
   __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
   _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
   spin_lock_bh include/linux/spinlock.h:356 [inline]
   sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
   bpf_prog_2c29ac5cdc6b1842+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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421
   trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
   kmem_cache_free+0x23c/0x2b0 mm/slub.c:4343
   __sigqueue_free kernel/signal.c:451 [inline]
   collect_signal kernel/signal.c:594 [inline]
   __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616
   dequeue_signal+0xd8/0x5a0 kernel/signal.c:636
   get_signal+0x5f7/0x1850 kernel/signal.c:2787
   arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
   exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
   exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
   irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225
   asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702


stack backtrace:
CPU: 1 PID: 5356 Comm: syz-fuzzer Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_bad_irq_dependency kernel/locking/lockdep.c:2626 [inline]
 check_irq_usage kernel/locking/lockdep.c:2865 [inline]
 check_prev_add kernel/locking/lockdep.c:3138 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x4dc7/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 sock_hash_delete_elem+0xb0/0x300 net/core/sock_map.c:939
 bpf_prog_2c29ac5cdc6b1842+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_run3+0x238/0x460 kernel/trace/bpf_trace.c:2421
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x23c/0x2b0 mm/slub.c:4343
 __sigqueue_free kernel/signal.c:451 [inline]
 collect_signal kernel/signal.c:594 [inline]
 __dequeue_signal+0x4ac/0x5c0 kernel/signal.c:616
 dequeue_signal+0xd8/0x5a0 kernel/signal.c:636
 get_signal+0x5f7/0x1850 kernel/signal.c:2787
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 irqentry_exit_to_user_mode+0x79/0x270 kernel/entry/common.c:225
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0033:0x50f320
Code: c4 18 5d c3 48 8b 4c 24 28 48 8b 11 48 8b 41 08 48 8b 52 18 90 ff d2 48 c1 f8 20 8b 4c 24 14 39 c8 7f e1 8b 4c 24 30 99 f7 f9 <89> d0 48 83 c4 18 5d c3 48 8d 05 d1 0e 56 00 48 8d 1d da 4a 94 00
RSP: 002b:000000c016b891a0 EFLAGS: 00000297
RAX: 0000000000009943 RBX: 0000000000000236 RCX: 000000000000c042
RDX: 0000000000009250 RSI: 731a5596983e0cd1 RDI: 000000000000c040
RBP: 000000c016b891b8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00007f71e59ceac8 R12: 0000000000470621
R13: 0000000000470621 R14: 000000c00ce076c0 R15: 0000000000000003
 </TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
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#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [syzbot] [bpf?] [net?] possible deadlock in __lock_task_sighand (2)
  2024-03-18 21:47 [syzbot] [net?] [bpf?] possible deadlock in __lock_task_sighand (2) syzbot
@ 2024-05-11  5:39 ` syzbot
  2024-05-11  5:58   ` Tetsuo Handa
  0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2024-05-11  5:39 UTC (permalink / raw)
  To: andrii, ast, bpf, daniel, davem, eddyz87, edumazet, haoluo, jakub,
	john.fastabend, jolsa, kpsingh, kuba, linux-kernel, martin.lau,
	netdev, pabeni, penguin-kernel, sdf, song, syzkaller-bugs,
	yonghong.song

syzbot has found a reproducer for the following issue on:

HEAD commit:    3e9bc0472b91 Merge branch 'bpf: Add BPF_PROG_TYPE_CGROUP_S..
git tree:       bpf
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1372d16c980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=98d5a8e00ed1044a
dashboard link: https://syzkaller.appspot.com/bug?extid=34267210261c2cbba2da
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=116aa704980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10be0fb8980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b4d98ec9bb7b/disk-3e9bc047.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/df7961b4e331/vmlinux-3e9bc047.xz
kernel image: https://storage.googleapis.com/syzbot-assets/be4e509c6f1b/bzImage-3e9bc047.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+34267210261c2cbba2da@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc5-syzkaller-00185-g3e9bc0472b91 #0 Not tainted
------------------------------------------------------
syz-executor188/5087 is trying to acquire lock:
ffff8880278b1298 (&sighand->siglock){-...}-{2:2}, at: __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414

but task is already holding lock:
ffff8880b95387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
ffff8880b95387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (lock#9){+.+.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
       __mmap_lock_do_trace_acquire_returned+0xa8/0x630 mm/mmap_lock.c:237
       __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
       mmap_read_trylock include/linux/mmap_lock.h:166 [inline]
       stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141
       __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449
       ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline]
       bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975
       0xffffffffa0001ff6
       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
       trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38
       switch_mm_irqs_off+0x7cb/0xae0
       context_switch kernel/sched/core.c:5393 [inline]
       __schedule+0x1066/0x4a50 kernel/sched/core.c:6746
       __schedule_loop kernel/sched/core.c:6823 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6838
       do_wait+0x2a5/0x560 kernel/exit.c:1636
       kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1790
       __do_sys_wait4 kernel/exit.c:1818 [inline]
       __se_sys_wait4 kernel/exit.c:1814 [inline]
       __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1814
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
       raw_spin_rq_lock kernel/sched/sched.h:1387 [inline]
       rq_lock kernel/sched/sched.h:1701 [inline]
       task_fork_fair+0x61/0x1e0 kernel/sched/fair.c:12635
       sched_cgroup_fork+0x37c/0x410 kernel/sched/core.c:4845
       copy_process+0x2217/0x3df0 kernel/fork.c:2499
       kernel_clone+0x226/0x8f0 kernel/fork.c:2797
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2875
       rest_init+0x23/0x300 init/main.c:704
       start_kernel+0x47a/0x500 init/main.c:1081
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x99/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #1 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 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
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:553 [inline]
       try_to_wake_up+0xb0/0x1470 kernel/sched/core.c:4262
       signal_wake_up_state+0xb4/0x120 kernel/signal.c:773
       signal_wake_up include/linux/sched/signal.h:448 [inline]
       complete_signal+0x94a/0xcf0 kernel/signal.c:1065
       __send_signal_locked+0xb1b/0xdc0 kernel/signal.c:1185
       do_notify_parent+0xd96/0x10a0 kernel/signal.c:2143
       exit_notify kernel/exit.c:757 [inline]
       do_exit+0x1811/0x27e0 kernel/exit.c:898
       do_group_exit+0x207/0x2c0 kernel/exit.c:1027
       __do_sys_exit_group kernel/exit.c:1038 [inline]
       __se_sys_exit_group kernel/exit.c:1036 [inline]
       __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sighand->siglock){-...}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 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
       __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414
       lock_task_sighand include/linux/sched/signal.h:746 [inline]
       do_send_sig_info kernel/signal.c:1300 [inline]
       group_send_sig_info+0x274/0x310 kernel/signal.c:1453
       bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881
       ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline]
       bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884
       bpf_prog_da8cbe553dc44a71+0x22/0x29
       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_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422
       trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline]
       __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 mm/mmap_lock.c:237
       __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
       mmap_read_trylock include/linux/mmap_lock.h:166 [inline]
       stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141
       __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449
       ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline]
       bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975
       bpf_prog_ec3b2eefa702d8d3+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
       trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38
       native_flush_tlb_multi+0x78/0xd0
       __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
       flush_tlb_multi arch/x86/mm/tlb.c:941 [inline]
       flush_tlb_mm_range+0x330/0x5c0 arch/x86/mm/tlb.c:1027
       flush_tlb_page arch/x86/include/asm/tlbflush.h:254 [inline]
       ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101
       wp_page_copy mm/memory.c:3329 [inline]
       do_wp_page+0x1c2e/0x4fd0 mm/memory.c:3660
       handle_pte_fault mm/memory.c:5316 [inline]
       __handle_mm_fault+0x264a/0x7240 mm/memory.c:5441
       handle_mm_fault+0x3c2/0x8a0 mm/memory.c:5606
       do_user_addr_fault arch/x86/mm/fault.c:1362 [inline]
       handle_page_fault arch/x86/mm/fault.c:1505 [inline]
       exc_page_fault+0x446/0x8e0 arch/x86/mm/fault.c:1563
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

other info that might help us debug this:

Chain exists of:
  &sighand->siglock --> &rq->__lock --> lock#9

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(lock#9);
                               lock(&rq->__lock);
                               lock(lock#9);
  lock(&sighand->siglock);

 *** DEADLOCK ***

9 locks held by syz-executor188/5087:
 #0: ffff88805fd07ec8 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:677 [inline]
 #0: ffff88805fd07ec8 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x730 mm/memory.c:5762
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #1: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __pte_offset_map+0x82/0x380 mm/pgtable-generic.c:285
 #2: ffff888021a43738 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffff888021a43738 (ptlock_ptr(ptdesc)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x1ba/0x300 mm/pgtable-generic.c:373
 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #3: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x114/0x420 kernel/trace/bpf_trace.c:2420
 #4: ffff888025328b20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:165 [inline]
 #4: ffff888025328b20 (&mm->mmap_lock){++++}-{3:3}, at: stack_map_get_build_id_offset+0x237/0x9d0 kernel/bpf/stackmap.c:141
 #5: ffff8880b95387e8 (lock#9){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
 #5: ffff8880b95387e8 (lock#9){+.+.}-{2:2}, at: __mmap_lock_do_trace_acquire_returned+0x8f/0x630 mm/mmap_lock.c:237
 #6: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #6: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #6: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_memcg_path_buf mm/mmap_lock.c:139 [inline]
 #6: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: get_mm_memcg_path+0xb1/0x600 mm/mmap_lock.c:209
 #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline]
 #7: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16e/0x490 kernel/trace/bpf_trace.c:2422
 #8: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #8: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #8: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: __lock_task_sighand+0x29/0x2e0 kernel/signal.c:1397

stack backtrace:
CPU: 1 PID: 5087 Comm: syz-executor188 Not tainted 6.9.0-rc5-syzkaller-00185-g3e9bc0472b91 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 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
 __lock_task_sighand+0x149/0x2e0 kernel/signal.c:1414
 lock_task_sighand include/linux/sched/signal.h:746 [inline]
 do_send_sig_info kernel/signal.c:1300 [inline]
 group_send_sig_info+0x274/0x310 kernel/signal.c:1453
 bpf_send_signal_common+0x2dd/0x430 kernel/trace/bpf_trace.c:881
 ____bpf_send_signal kernel/trace/bpf_trace.c:886 [inline]
 bpf_send_signal+0x19/0x30 kernel/trace/bpf_trace.c:884
 bpf_prog_da8cbe553dc44a71+0x22/0x29
 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_run4+0x25a/0x490 kernel/trace/bpf_trace.c:2422
 trace_mmap_lock_acquire_returned include/trace/events/mmap_lock.h:52 [inline]
 __mmap_lock_do_trace_acquire_returned+0x5c8/0x630 mm/mmap_lock.c:237
 __mmap_lock_trace_acquire_returned include/linux/mmap_lock.h:36 [inline]
 mmap_read_trylock include/linux/mmap_lock.h:166 [inline]
 stack_map_get_build_id_offset+0x9b2/0x9d0 kernel/bpf/stackmap.c:141
 __bpf_get_stack+0x4ad/0x5a0 kernel/bpf/stackmap.c:449
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1985 [inline]
 bpf_get_stack_raw_tp+0x1a3/0x240 kernel/trace/bpf_trace.c:1975
 bpf_prog_ec3b2eefa702d8d3+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
 trace_tlb_flush+0x118/0x140 include/trace/events/tlb.h:38
 native_flush_tlb_multi+0x78/0xd0
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:941 [inline]
 flush_tlb_mm_range+0x330/0x5c0 arch/x86/mm/tlb.c:1027
 flush_tlb_page arch/x86/include/asm/tlbflush.h:254 [inline]
 ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101
 wp_page_copy mm/memory.c:3329 [inline]
 do_wp_page+0x1c2e/0x4fd0 mm/memory.c:3660
 handle_pte_fault mm/memory.c:5316 [inline]
 __handle_mm_fault+0x264a/0x7240 mm/memory.c:5441
 handle_mm_fault+0x3c2/0x8a0 mm/memory.c:5606
 do_user_addr_fault arch/x86/mm/fault.c:1362 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x446/0x8e0 arch/x86/mm/fault.c:1563
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f6a162a6260
Code: 41 54 55 48 89 f5 53 89 fb 48 83 ec 18 48 83 3d 8d 0d 0a 00 00 89 54 24 0c 74 08 84 c9 0f 85 09 02 00 00 31 c0 ba 01 00 00 00 <f0> 0f b1 15 80 3a 0a 00 0f 85 0f 02 00 00 4c 8d 25 73 3a 0a 00 4c
RSP: 002b:00007ffd4827c420 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 00007f6a16347120 RDI: 0000000000000000
RBP: 00007f6a16347120 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
 </TASK>


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [syzbot] [bpf?] [net?] possible deadlock in __lock_task_sighand (2)
  2024-05-11  5:39 ` [syzbot] [bpf?] [net?] " syzbot
@ 2024-05-11  5:58   ` Tetsuo Handa
  0 siblings, 0 replies; 3+ messages in thread
From: Tetsuo Handa @ 2024-05-11  5:58 UTC (permalink / raw)
  To: syzbot, andrii, ast, bpf, daniel, davem, eddyz87, edumazet,
	haoluo, jakub, john.fastabend, jolsa, kpsingh, kuba, linux-kernel,
	martin.lau, netdev, pabeni, sdf, song, syzkaller-bugs,
	yonghong.song

This bug report has fix commit but syzbot found a reproducer with that fix commit applied.
That is, something is still wrong. Any comments from BPF people on
https://lkml.kernel.org/r/8dc01a83-1bea-4e3c-a04d-9a9bd422a5b3@I-love.SAKURA.ne.jp ?

On 2024/05/11 14:39, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    3e9bc0472b91 Merge branch 'bpf: Add BPF_PROG_TYPE_CGROUP_S..
> git tree:       bpf
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=1372d16c980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=98d5a8e00ed1044a
> dashboard link: https://syzkaller.appspot.com/bug?extid=34267210261c2cbba2da
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=116aa704980000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10be0fb8980000


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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2024-03-18 21:47 [syzbot] [net?] [bpf?] possible deadlock in __lock_task_sighand (2) syzbot
2024-05-11  5:39 ` [syzbot] [bpf?] [net?] " syzbot
2024-05-11  5:58   ` Tetsuo Handa

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