bisecting fixing commit since 4762bcd451a9e92e79d5146d3d4a5ffe2b4e0ec5
building syzkaller on 048f2d494ee4a016e2386c28bf8cccdd87896cbd
testing commit 4762bcd451a9e92e79d5146d3d4a5ffe2b4e0ec5 with gcc (GCC) 8.1.0
kernel signature: 6f398fa04553812f88c455609bb8b6e4a89fea97194ed66bb8e42482a7cddb5c
run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #1: crashed: general protection fault in rxrpc_get_skb
run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #4: crashed: general protection fault in rxrpc_get_skb
run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in rxrpc_send_data_packet
testing current HEAD 773e2b1cd56a17bab4cdd4fe7db12f2140951668
testing commit 773e2b1cd56a17bab4cdd4fe7db12f2140951668 with gcc (GCC) 8.1.0
kernel signature: 6c6b5148d06690935d1a3a6553203e5ebb91d4a6ba87b18613bc2793ff65a19a
all runs: crashed: general protection fault in rxrpc_get_skb
revisions tested: 2, total time: 25m49.65674444s (build: 17m51.673396151s, test: 6m41.055250876s)
the crash still happens on HEAD
commit msg: Linux 4.14.178
crash: general protection fault in rxrpc_get_skb
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: 1 PID: 2774 Comm: kworker/1:2 Not tainted 4.14.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krxrpcd rxrpc_process_call
task: ffff88809eeea0c0 task.stack: ffff88809eef8000
RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline]
RIP: 0010:refcount_read include/linux/refcount.h:42 [inline]
RIP: 0010:rxrpc_get_skb+0x57/0x2f0 net/rxrpc/skbuff.c:52
RSP: 0018:ffff88809eeffc60 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 00000000000000e4 RCX: 0000000000000000
RDX: 000000000000001c RSI: 000000000000000a RDI: 0000000000000000
RBP: ffff88809eeffca8 R08: ffff88809eeea9b8 R09: 0000000000005e48
R10: 0000000000000050 R11: ffff88809eeea0c0 R12: 000000000000000a
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000008f137000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rxrpc_resend net/rxrpc/call_event.c:319 [inline]
 rxrpc_process_call+0x4e1/0xff9 net/rxrpc/call_event.c:407
 process_one_work+0x79e/0x16c0 kernel/workqueue.c:2116
 worker_thread+0xcc/0xee0 kernel/workqueue.c:2250
 kthread+0x338/0x400 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: 89 45 d0 48 c7 c0 a0 de e0 89 48 0f 46 c2 f0 44 0f c1 28 48 8d 9f e4 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <0f> b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 
RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88809eeffc60
RIP: atomic_read arch/x86/include/asm/atomic.h:27 [inline] RSP: ffff88809eeffc60
RIP: refcount_read include/linux/refcount.h:42 [inline] RSP: ffff88809eeffc60
RIP: rxrpc_get_skb+0x57/0x2f0 net/rxrpc/skbuff.c:52 RSP: ffff88809eeffc60
---[ end trace a535c4cbba5eddd6 ]---