syzbot has found a reproducer for the following issue on: HEAD commit: ed30a4a51bb1 Linux 6.9-rc5 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15124c3b180000 kernel config: https://syzkaller.appspot.com/x/.config?x=545d4b3e07d6ccbc dashboard link: https://syzkaller.appspot.com/bug?extid=a4ed4041b9bea8177ac3 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=102d66bf180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10107f67180000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-ed30a4a5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c62dd6fbdae1/vmlinux-ed30a4a5.xz kernel image: https://storage.googleapis.com/syzbot-assets/2ee0879390c1/bzImage-ed30a4a5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a4ed4041b9bea8177ac3@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.9.0-rc5-syzkaller #0 Not tainted -------------------------------------------- syz-executor381/5177 is trying to acquire lock: ffff888027aca200 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888027aca200 (&stab->lock){+...}-{2:2}, at: __sock_map_delete+0x43/0xe0 net/core/sock_map.c:417 but task is already holding lock: ffff888027acaa00 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888027acaa00 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x197/0x870 net/core/sock_map.c:493 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&stab->lock); lock(&stab->lock); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor381/5177: #0: ffff88802f6ad258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline] #0: ffff88802f6ad258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_sk_acquire net/core/sock_map.c:117 [inline] #0: ffff88802f6ad258 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: sock_map_update_elem_sys+0x1b6/0x570 net/core/sock_map.c:578 #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: sock_map_sk_acquire net/core/sock_map.c:118 [inline] #1: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: sock_map_update_elem_sys+0x1d8/0x570 net/core/sock_map.c:578 #2: ffff888027acaa00 (&stab->lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #2: ffff888027acaa00 (&stab->lock){+...}-{2:2}, at: sock_map_update_common+0x197/0x870 net/core/sock_map.c:493 #3: ffff88801a940290 (&psock->link_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff88801a940290 (&psock->link_lock){+...}-{2:2}, at: sock_map_del_link net/core/sock_map.c:145 [inline] #3: ffff88801a940290 (&psock->link_lock){+...}-{2:2}, at: sock_map_unref+0xbf/0x6e0 net/core/sock_map.c:180 #4: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #4: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #4: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #4: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xe4/0x420 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 3 PID: 5177 Comm: syz-executor381 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] __sock_map_delete+0x43/0xe0 net/core/sock_map.c:417 sock_map_delete_elem+0xb5/0x100 net/core/sock_map.c:449 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:1997 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2236 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+0x151/0x420 kernel/trace/bpf_trace.c:2420 trace_kfree include/trace/events/kmem.h:94 [inline] kfree+0x225/0x390 mm/slub.c:4377 sk_psock_free_link include/linux/skmsg.h:421 [inline] sock_map_del_link net/core/sock_map.c:158 [inline] sock_map_unref+0x392/0x6e0 net/core/sock_map.c:180 sock_map_update_common+0x4f3/0x870 net/core/sock_map.c:506 sock_map_update_elem_sys+0x3bb/0x570 net/core/sock_map.c:582 bpf_map_update_value+0x36c/0x6c0 kernel/bpf/syscall.c:172 map_update_elem+0x623/0x910 kernel/bpf/syscall.c:1641 __sys_bpf+0xab9/0x4b40 kernel/bpf/syscall.c:5648 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5765 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6bcc5b7729 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 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:00007fff751f0718 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fff751f08e8 RCX: 00007f6bcc5b7729 RDX: 0000000000000020 RSI: 0000000020000680 RDI: 0000000000000002 RBP: 00007f6bcc62a610 R08: 00007fff751f08e8 R09: 00007fff751f08e8 R10: 00007fff751f08e8 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff751f08d8 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.
