====================================================== WARNING: possible circular locking dependency detected 5.17.0-rc7-syzkaller-00068-ge7e19defa575 #0 Not tainted ------------------------------------------------------ syz-executor.5/19055 is trying to acquire lock: ffff88801cef8678 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:87 [inline] ffff88801cef8678 (&u->lock/1){+.+.}-{2:2}, at: sk_diag_fill+0xaaf/0x10d0 net/unix/diag.c:155 but task is already holding lock: ffff88801cefb9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] ffff88801cefb9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:69 [inline] ffff88801cefb9e8 (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:3341 unix_dgram_sendmsg+0xeeb/0x1a10 net/unix/af_unix.c:2027 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 io_send+0x1bd/0x450 fs/io_uring.c:4995 io_issue_sqe+0x3767/0x7300 fs/io_uring.c:6774 __io_queue_sqe fs/io_uring.c:7098 [inline] io_queue_sqe fs/io_uring.c:7140 [inline] io_submit_sqe fs/io_uring.c:7348 [inline] io_submit_sqes+0x1046/0x9100 fs/io_uring.c:7454 __do_sys_io_uring_enter+0xfdd/0x1fc0 fs/io_uring.c:10162 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c -> #0 (&u->lock/1){+.+.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 _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+0x3b9/0x620 net/unix/diag.c:221 netlink_dump+0x4b2/0xb70 net/netlink/af_netlink.c:2268 __netlink_dump_start+0x644/0x900 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] unix_diag_handler_dump+0x43b/0x840 net/unix/diag.c:320 __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:2494 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x289/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2074 [inline] do_iter_readv_writev+0x47a/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_writev+0x1aa/0x630 fs/read_write.c:924 do_writev+0x27f/0x300 fs/read_write.c:967 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c 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 *** 5 locks held by syz-executor.5/19055: #0: ffffffff8d33d148 (sock_diag_mutex){+.+.}-{3:3}, at: sock_diag_rcv+0x17/0x40 net/core/sock_diag.c:276 #1: ffffffff8d33d2c8 (sock_diag_table_mutex){+.+.}-{3:3}, at: __sock_diag_cmd net/core/sock_diag.c:230 [inline] #1: ffffffff8d33d2c8 (sock_diag_table_mutex){+.+.}-{3:3}, at: sock_diag_rcv_msg+0x19b/0x440 net/core/sock_diag.c:266 #2: ffff88801d513680 (nlk_cb_mutex-SOCK_DIAG){+.+.}-{3:3}, at: netlink_dump+0xb0/0xb70 net/netlink/af_netlink.c:2223 #3: ffffffff908b9e98 (&unix_table_locks[i]){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #3: ffffffff908b9e98 (&unix_table_locks[i]){+.+.}-{2:2}, at: unix_diag_dump+0x186/0x620 net/unix/diag.c:213 #4: ffff88801cefb9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline] #4: ffff88801cefb9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_dump_icons net/unix/diag.c:69 [inline] #4: ffff88801cefb9e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: sk_diag_fill+0x9c3/0x10d0 net/unix/diag.c:155 stack backtrace: CPU: 1 PID: 19055 Comm: syz-executor.5 Not tainted 5.17.0-rc7-syzkaller-00068-ge7e19defa575 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:2143 check_prev_add kernel/locking/lockdep.c:3063 [inline] check_prevs_add kernel/locking/lockdep.c:3186 [inline] validate_chain kernel/locking/lockdep.c:3801 [inline] __lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5639 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604 _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+0x3b9/0x620 net/unix/diag.c:221 netlink_dump+0x4b2/0xb70 net/netlink/af_netlink.c:2268 __netlink_dump_start+0x644/0x900 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] unix_diag_handler_dump+0x43b/0x840 net/unix/diag.c:320 __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:2494 sock_diag_rcv+0x26/0x40 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x539/0x7e0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x289/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2074 [inline] do_iter_readv_writev+0x47a/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_writev+0x1aa/0x630 fs/read_write.c:924 do_writev+0x27f/0x300 fs/read_write.c:967 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf6f08549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f59025cc EFLAGS: 00000296 ORIG_RAX: 0000000000000092 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000200000c0 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi