====================================================== WARNING: possible circular locking dependency detected 5.19.0-rc4-next-20220628-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/3509 is trying to acquire lock: ffff8880765fae70 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:87 [inline] ffff8880765fae70 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_fill+0xaaf/0x10d0 net/unix/diag.c:155 but task is already holding lock: ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:360 [inline] ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:69 [inline] ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_fill+0x9c3/0x10d0 net/unix/diag.c:155 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (rlock-AF_UNIX){+.+.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 skb_queue_tail+0x21/0x140 net/core/skbuff.c:3371 unix_dgram_sendmsg+0xf5a/0x1b60 net/unix/af_unix.c:2015 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 io_send+0x26b/0x780 io_uring/net.c:266 io_issue_sqe+0x15e/0xd20 io_uring/io_uring.c:1601 io_queue_sqe io_uring/io_uring.c:1778 [inline] io_submit_sqe io_uring/io_uring.c:2036 [inline] io_submit_sqes+0x9a6/0x1ec0 io_uring/io_uring.c:2147 __do_sys_io_uring_enter+0xb85/0x1eb0 io_uring/io_uring.c:3087 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 -> #0 (&u->lock/1){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:378 sk_diag_dump_icons net/unix/diag.c:87 [inline] sk_diag_fill+0xaaf/0x10d0 net/unix/diag.c:155 sk_diag_dump net/unix/diag.c:193 [inline] unix_diag_dump+0x3a9/0x640 net/unix/diag.c:217 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380 netlink_dump_start include/linux/netlink.h:245 [inline] unix_diag_handler_dump net/unix/diag.c:315 [inline] unix_diag_handler_dump+0x5c2/0x830 net/unix/diag.c:304 __sock_diag_cmd net/core/sock_diag.c:235 [inline] sock_diag_rcv_msg+0x31a/0x440 net/core/sock_diag.c:266 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_no_sendpage+0xff/0x140 net/core/sock.c:3162 kernel_sendpage.part.0+0x1d5/0x700 net/socket.c:3564 kernel_sendpage net/socket.c:3561 [inline] sock_sendpage+0xdf/0x140 net/socket.c:1054 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] do_splice+0xb57/0x1920 fs/splice.c:1079 __do_splice+0x134/0x250 fs/splice.c:1144 __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice fs/splice.c:1332 [inline] __x64_sys_splice+0x198/0x250 fs/splice.c:1332 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rlock-AF_UNIX); lock(&u->lock/1); lock(rlock-AF_UNIX); lock(&u->lock/1); *** DEADLOCK *** 6 locks held by syz-executor.3/3509: #0: ffff888074fac468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock_nested fs/pipe.c:82 [inline] #0: ffff888074fac468 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_lock+0x5a/0x70 fs/pipe.c:90 #1: ffffffff8d5aef88 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x17/0x40 net/core/sock_diag.c:276 #2: ffffffff8d5af108 (sock_diag_table_mutex){+.+.}-{3:3}, at: __sock_diag_cmd net/core/sock_diag.c:230 [inline] #2: ffffffff8d5af108 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0x19b/0x440 net/core/sock_diag.c:266 #3: ffff88801d907678 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xae/0xc20 net/netlink/af_netlink.c:2223 #4: ffff888046a7a798 (&net->unx.table.locks[i]){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:360 [inline] #4: ffff888046a7a798 (&net->unx.table.locks[i]){+.+.}-{2:2}, at: unix_diag_dump+0x1b4/0x640 net/unix/diag.c:211 #5: ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:360 [inline] #5: ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:69 [inline] #5: ffff8880765fe9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_fill+0x9c3/0x10d0 net/unix/diag.c:155 stack backtrace: CPU: 1 PID: 3509 Comm: syz-executor.3 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x2abe/0x5660 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:378 sk_diag_dump_icons net/unix/diag.c:87 [inline] sk_diag_fill+0xaaf/0x10d0 net/unix/diag.c:155 sk_diag_dump net/unix/diag.c:193 [inline] unix_diag_dump+0x3a9/0x640 net/unix/diag.c:217 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380 netlink_dump_start include/linux/netlink.h:245 [inline] unix_diag_handler_dump net/unix/diag.c:315 [inline] unix_diag_handler_dump+0x5c2/0x830 net/unix/diag.c:304 __sock_diag_cmd net/core/sock_diag.c:235 [inline] sock_diag_rcv_msg+0x31a/0x440 net/core/sock_diag.c:266 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 sock_no_sendpage+0xff/0x140 net/core/sock.c:3162 kernel_sendpage.part.0+0x1d5/0x700 net/socket.c:3564 kernel_sendpage net/socket.c:3561 [inline] sock_sendpage+0xdf/0x140 net/socket.c:1054 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] do_splice+0xb57/0x1920 fs/splice.c:1079 __do_splice+0x134/0x250 fs/splice.c:1144 __do_sys_splice fs/splice.c:1350 [inline] __se_sys_splice fs/splice.c:1332 [inline] __x64_sys_splice+0x198/0x250 fs/splice.c:1332 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f94a7089209 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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:00007f94a8105168 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f94a719bf60 RCX: 00007f94a7089209 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f94a70e3161 R08: 0000000080000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd5cb777cf R14: 00007f94a8105300 R15: 0000000000022000