general protection fault in rds_recv_rcvbuf_delta

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: b0cdffaa Linux 4.14.163
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1294a021e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=19269c071a1fe30
dashboard link: https://syzkaller.appspot.com/bug?extid=53cd2e04ec0a4448d797
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+53cd2e...@syzkaller.appspotmail.com

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
Modules linked in:
CPU: 0 PID: 10636 Comm: syz-executor.3 Not tainted 4.14.163-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
task: ffff8880437624c0 task.stack: ffff888043620000
RIP: 0010:rds_recv_rcvbuf_delta.part.0+0x134/0x3c0 net/rds/recv.c:108
RSP: 0018:ffff8880436277a8 EFLAGS: 00010007
RAX: dffffc0000000000 RBX: ffff8880437f0e40 RCX: ffffc90008e3c000
RDX: 0000000000000005 RSI: ffffffff85fbeb75 RDI: 000000000000002c
RBP: ffff8880436277e8 R08: 1ffff110120192c6 R09: ffffffff895917c8
R10: ffff888043762d40 R11: ffff8880437624c0 R12: 0000000000000000
R13: ffff8880437f1324 R14: 000000000002c9c0 R15: ffff888098ffa600
FS: 00007f7c067cd700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bf22000 CR3: 000000009f903000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rds_recv_rcvbuf_delta net/rds/recv.c:382 [inline]
rds_recv_incoming+0x652/0x1020 net/rds/recv.c:382
rds_loop_xmit+0x147/0x320 net/rds/loop.c:82
rds_send_xmit+0xd2c/0x1cd0 net/rds/send.c:349
rds_sendmsg+0x2fb/0x1db0 net/rds/send.c:1197
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
___sys_sendmsg+0x70a/0x840 net/socket.c:2062
__sys_sendmsg+0xb9/0x140 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2103
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45af49
RSP: 002b:00007f7c067ccc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7c067cd6d4
R13: 00000000004caa25 R14: 00000000004e3ea8 R15: 00000000ffffffff
Code: 48 c1 ea 03 80 3c 02 00 0f 85 45 02 00 00 4c 8b a3 80 04 00 00 48 b8
00 00 00 00 00 fc ff df 49 8d 7c 24 2c 48 89 fa 48 c1 ea 03 <0f> b6 14 02
48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
RIP: rds_recv_rcvbuf_delta.part.0+0x134/0x3c0 net/rds/recv.c:108 RSP:
ffff8880436277a8
---[ end trace ee95b14c6126711c ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.