Hello, syzbot found the following issue on: HEAD commit: 3245cb65fd91 Merge tag 'devicetree-fixes-for-6.0-2' of git.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12b0c487080000 kernel config: https://syzkaller.appspot.com/x/.config?x=98a30118ec9215e9 dashboard link: https://syzkaller.appspot.com/bug?extid=44b38bcb874d81a15a57 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+44b38bcb874d81a15a57@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc5-syzkaller-00025-g3245cb65fd91 #0 Not tainted ------------------------------------------------------ syz-executor.4/21149 is trying to acquire lock: ffff8880178441e8 (rlock-AF_UNIX){+.+.}-{2:2}, at: skb_queue_tail+0x21/0x140 net/core/skbuff.c:3400 but task is already holding lock: ffff888017844670 (&u->lock/1){+.+.}-{2:2}, at: unix_state_double_lock net/unix/af_unix.c:1298 [inline] ffff888017844670 (&u->lock/1){+.+.}-{2:2}, at: unix_state_double_lock+0x77/0xa0 net/unix/af_unix.c:1290 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&u->lock/1){+.+.}-{2:2}: _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_write_iter+0x291/0x3d0 net/socket.c:1108 call_write_iter include/linux/fs.h:2187 [inline] do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:729 do_iter_write+0x182/0x700 fs/read_write.c:855 vfs_writev+0x1aa/0x630 fs/read_write.c:928 do_writev+0x279/0x2f0 fs/read_write.c:971 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+0x70/0x82 -> #0 (rlock-AF_UNIX){+.+.}-{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+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __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:3400 unix_dgram_sendmsg+0xf41/0x1b50 net/unix/af_unix.c:2043 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482 __sys_sendmsg_sock+0x26/0x30 net/socket.c:2548 io_sendmsg+0x246/0x7d0 io_uring/net.c:289 io_issue_sqe+0x6b6/0xd20 io_uring/io_uring.c:1577 io_queue_sqe io_uring/io_uring.c:1755 [inline] io_submit_sqe io_uring/io_uring.c:2013 [inline] io_submit_sqes+0x94e/0x1d30 io_uring/io_uring.c:2124 __do_sys_io_uring_enter+0xb85/0x1ea0 io_uring/io_uring.c:3054 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+0x70/0x82 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&u->lock/1); lock(rlock-AF_UNIX); lock(&u->lock/1); lock(rlock-AF_UNIX); *** DEADLOCK *** 2 locks held by syz-executor.4/21149: #0: ffff88807dcb40a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xb7a/0x1ea0 io_uring/io_uring.c:3053 #1: ffff888017844670 (&u->lock/1){+.+.}-{2:2}, at: unix_state_double_lock net/unix/af_unix.c:1298 [inline] #1: ffff888017844670 (&u->lock/1){+.+.}-{2:2}, at: unix_state_double_lock+0x77/0xa0 net/unix/af_unix.c:1290 stack backtrace: CPU: 0 PID: 21149 Comm: syz-executor.4 Not tainted 6.0.0-rc5-syzkaller-00025-g3245cb65fd91 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: <TASK> __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+0x2a43/0x56d0 kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5666 [inline] lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5631 __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:3400 unix_dgram_sendmsg+0xf41/0x1b50 net/unix/af_unix.c:2043 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2482 __sys_sendmsg_sock+0x26/0x30 net/socket.c:2548 io_sendmsg+0x246/0x7d0 io_uring/net.c:289 io_issue_sqe+0x6b6/0xd20 io_uring/io_uring.c:1577 io_queue_sqe io_uring/io_uring.c:1755 [inline] io_submit_sqe io_uring/io_uring.c:2013 [inline] io_submit_sqes+0x94e/0x1d30 io_uring/io_uring.c:2124 __do_sys_io_uring_enter+0xb85/0x1ea0 io_uring/io_uring.c:3054 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+0x70/0x82 RIP: 0023:0xf7faf549 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:00000000f7f895cc EFLAGS: 00000296 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000002a6e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> ---------------- 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 --- This report is generated by a bot. 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