Hello,
syzbot found the following issue on:
HEAD commit: e5cd595e23c1 Linux 6.1.83
git tree: linux-6.1.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=17a5e83d180000
kernel config:
https://syzkaller.appspot.com/x/.config?x=99d0cbbc2b2c7cfd
dashboard link:
https://syzkaller.appspot.com/bug?extid=6c4a9954273658c1d222
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/607b4730a2cc/disk-e5cd595e.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/265e84c69ac5/vmlinux-e5cd595e.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/af893c46019b/bzImage-e5cd595e.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+6c4a99...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.1.83-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/5635 is trying to acquire lock:
ffff8880574f5290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff8880574f5290 (&psock->link_lock){+...}-{2:2}, at: sock_map_add_link net/core/sock_map.c:136 [inline]
ffff8880574f5290 (&psock->link_lock){+...}-{2:2}, at: sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:502
but task is already holding lock:
ffff88805ac73240 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:492
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&stab->lock){+.-.}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
__sock_map_delete net/core/sock_map.c:416 [inline]
sock_map_delete_elem+0x97/0x130 net/core/sock_map.c:448
0xffffffffa0002073
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
__bpf_trace_kfree+0x6e/0x90 include/trace/events/kmem.h:94
trace_kfree include/trace/events/kmem.h:94 [inline]
kfree+0xf6/0x190 mm/slab_common.c:994
sk_psock_free_link include/linux/skmsg.h:416 [inline]
sock_map_del_link net/core/sock_map.c:160 [inline]
sock_map_unref+0x3ac/0x5d0 net/core/sock_map.c:182
sock_hash_delete_elem+0x273/0x2f0 net/core/sock_map.c:936
map_delete_elem+0x3ff/0x550 kernel/bpf/syscall.c:1501
__sys_bpf+0x350/0x6c0 kernel/bpf/syscall.c:4996
__do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
-> #0 (&psock->link_lock){+...}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_map_add_link net/core/sock_map.c:136 [inline]
sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:502
sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:581
map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448
__sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993
__do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&stab->lock);
lock(&psock->link_lock);
lock(&stab->lock);
lock(&psock->link_lock);
*** DEADLOCK ***
3 locks held by syz-executor.3/5635:
#0: ffff88807dab2130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1745 [inline]
#0: ffff88807dab2130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:119 [inline]
#0: ffff88807dab2130 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1c8/0x910 net/core/sock_map.c:577
#1: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#1: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#1: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:120 [inline]
#1: ffffffff8d12a940 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d4/0x910 net/core/sock_map.c:577
#2: ffff88805ac73240 (&stab->lock){+.-.}-{2:2}, at: sock_map_update_common+0x1b6/0x5b0 net/core/sock_map.c:492
stack backtrace:
CPU: 1 PID: 5635 Comm: syz-executor.3 Not tainted 6.1.83-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
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
sock_map_add_link net/core/sock_map.c:136 [inline]
sock_map_update_common+0x31c/0x5b0 net/core/sock_map.c:502
sock_map_update_elem_sys+0x55b/0x910 net/core/sock_map.c:581
map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448
__sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993
__do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f70f627dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f70f4dfe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f70f63abf80 RCX: 00007f70f627dda9
RDX: 0000000000000020 RSI: 0000000020000740 RDI: 0000000000000002
RBP: 00007f70f62ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f70f63abf80 R15: 00007ffce41011b8
</TASK>
---
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