Subject: WARNING in rxrpc_recvmsg

From: syzbot <[email-masked]>
Date: Fri, 03 Jul 2020 16:31:22 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    cd77006e Merge tag 'hyperv-fixes-signed' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=134c490f100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7be693511b29b338
dashboard link: https://syzkaller.appspot.com/bug?extid=1a68d5c4e74edea44294
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1176e39b100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=144c9e6d100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 11007 at kernel/locking/mutex.c:1415 mutex_trylock+0x220/0x2c0 kernel/locking/mutex.c:1415
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 11007 Comm: syz-executor947 Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:231
 __warn.cold+0x20/0x45 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:235
 exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:255
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:563
RIP: 0010:mutex_trylock+0x220/0x2c0 kernel/locking/mutex.c:1415
Code: 08 84 d2 0f 85 99 00 00 00 8b 3d cb 07 c8 02 85 ff 0f 85 6a fe ff ff 48 c7 c6 60 9c 4b 88 48 c7 c7 20 9a 4b 88 e8 82 77 5e f9 <0f> 0b e9 50 fe ff ff ff 74 24 38 48 8d 7b 68 45 31 c9 31 c9 41 b8
RSP: 0018:ffffc90008757818 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888093a14378 RCX: 0000000000000000
RDX: ffff8880924b61c0 RSI: ffffffff815d4f47 RDI: fffff520010eaef5
RBP: ffff888093a14000 R08: 0000000000000000 R09: ffffffff89bb5ba3
R10: 000000000000059f R11: 0000000000000001 R12: ffffffff8c90d1a0
R13: ffff888093a14340 R14: 0000000000000000 R15: ffff888093a14538
 rxrpc_recvmsg+0x695/0x1a03 net/rxrpc/recvmsg.c:593
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 sock_recvmsg net/socket.c:900 [inline]
 ____sys_recvmsg+0x2c4/0x640 net/socket.c:2575
 ___sys_recvmsg+0x127/0x200 net/socket.c:2617
 do_recvmmsg+0x24d/0x6d0 net/socket.c:2715
 __sys_recvmmsg net/socket.c:2794 [inline]
 __do_sys_recvmmsg net/socket.c:2817 [inline]
 __se_sys_recvmmsg net/socket.c:2810 [inline]
 __x64_sys_recvmmsg+0x20b/0x260 net/socket.c:2810
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x447b79
Code: Bad RIP value.
RSP: 002b:00007fdf4e75dce8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000006dcc48 RCX: 0000000000447b79
RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00000000006dcc40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc4c
R13: 00007ffc658e40ef R14: 00007fdf4e75e9c0 R15: 20c49ba5e353f7cf
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
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