Hi, We would like to report the following bug which has been found by our modified version of syzkaller. ====================================================== description: general protection fault in sock_def_error_report affected file: net/core/sock.c kernel version: 5.4.206 kernel commit: 6584107915561f860b7b05dcca5c903dd62a308d git tree: upstream kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=1aab6d4187ddf667 crash reproducer: We could only generate the syz-repro for this bug. The corresponding C-repro does not trigger the bug. The syz-repo can be run as: `syz-execprog -executor=./syz-executor -repeat=0 -procs=16 -cover=0 repro.syz` ====================================================== Crash log: ====================================================== kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 5480 Comm: syz-executor.2 Tainted: G OE 5.4.206+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:__wake_up_common+0x198/0x650 kernel/sched/wait.c:86 Code: 18 48 39 1c 24 0f 85 eb 01 00 00 8b 44 24 10 48 83 c4 28 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8d 54 24 18 48 89 d0 48 c1 e8 03 <80> 3c 28 00 0f 85 c1 02 00 00 49 8b 44 24 18 4d 89 e0 48 83 e8 18 RSP: 0018:ffff8880b25ff4b0 EFLAGS: 00010802 RAX: 1bd5a00000000020 RBX: 0000000000000002 RCX: ffffc900080f5000 RDX: dead000000000100 RSI: ffffffff81c30ef8 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88809f932380 R09: ffffed101637d55d R10: 00000000000000a0 R11: ffff88809f932380 R12: dead0000000000e8 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f53462e4700(0000) GS:ffff88811a000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f75554d1098 CR3: 00000000b1a27004 CR4: 0000000000160ef0 Call Trace: __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:123 sock_def_error_report+0x16a/0x590 net/core/sock.c:2817 tcp_disconnect+0x14b9/0x1dc0 net/ipv4/tcp.c:2701 __inet_stream_connect+0xb44/0xe60 net/ipv4/af_inet.c:707 tcp_sendmsg_fastopen net/ipv4/tcp.c:1176 [inline] tcp_sendmsg_locked+0x22b9/0x3220 net/ipv4/tcp.c:1218 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1445 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:807 smc_sendmsg+0x31f/0x3f0 net/smc/af_smc.c:1566 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd3/0x130 net/socket.c:657 ____sys_sendmsg+0x304/0x7e0 net/socket.c:2286 ___sys_sendmsg+0x11d/0x1b0 net/socket.c:2340 __sys_sendmmsg+0x195/0x480 net/socket.c:2443 __do_sys_sendmmsg net/socket.c:2472 [inline] __se_sys_sendmmsg net/socket.c:2469 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2469 do_syscall_64+0xf6/0x7b0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f53483544ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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:00007f53462e3be8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f5348473040 RCX: 00007f53483544ed RDX: 0000000000000001 RSI: 0000000020001a80 RDI: 0000000000000003 RBP: 00007f53483c02e1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000084 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcd7ac395f R14: 00007f5348473040 R15: 00007f53462e3d80 Modules linked in: uio_ivshmem(OE) uio(E) ---[ end trace d3594c146e1822a7 ]--- RIP: 0010:__wake_up_common+0x198/0x650 kernel/sched/wait.c:86 Code: 18 48 39 1c 24 0f 85 eb 01 00 00 8b 44 24 10 48 83 c4 28 5b 5d 41 5c 41 5d 41 5e 41 5f c3 49 8d 54 24 18 48 89 d0 48 c1 e8 03 <80> 3c 28 00 0f 85 c1 02 00 00 49 8b 44 24 18 4d 89 e0 48 83 e8 18 RSP: 0018:ffff8880b25ff4b0 EFLAGS: 00010802 RAX: 1bd5a00000000020 RBX: 0000000000000002 RCX: ffffc900080f5000 RDX: dead000000000100 RSI: ffffffff81c30ef8 RDI: 0000000000000001 RBP: dffffc0000000000 R08: ffff88809f932380 R09: ffffed101637d55d R10: 00000000000000a0 R11: ffff88809f932380 R12: dead0000000000e8 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f53462e4700(0000) GS:ffff88811a000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f75554d1098 CR3: 00000000b1a27004 CR4: 0000000000160ef0 ---------------- Code disassembly (best guess): 0: 18 48 39 sbb %cl,0x39(%rax) 3: 1c 24 sbb $0x24,%al 5: 0f 85 eb 01 00 00 jne 0x1f6 b: 8b 44 24 10 mov 0x10(%rsp),%eax f: 48 83 c4 28 add $0x28,%rsp 13: 5b pop %rbx 14: 5d pop %rbp 15: 41 5c pop %r12 17: 41 5d pop %r13 19: 41 5e pop %r14 1b: 41 5f pop %r15 1d: c3 retq 1e: 49 8d 54 24 18 lea 0x18(%r12),%rdx 23: 48 89 d0 mov %rdx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) <-- trapping instruction 2e: 0f 85 c1 02 00 00 jne 0x2f5 34: 49 8b 44 24 18 mov 0x18(%r12),%rax 39: 4d 89 e0 mov %r12,%r8 3c: 48 83 e8 18 sub $0x18,%rax -- Thanks and Regards, Dipanjan