bisecting fixing commit since c63ee2939dc1c6eee6c544af1b4ab441490bfe6e
building syzkaller on 598ca6c8b8766304c3b2865e38f5f301c39bd299
testing commit c63ee2939dc1c6eee6c544af1b4ab441490bfe6e
compiler: gcc version 8.4.1 20210217 (GCC)
kernel signature: 7b1e077c60367c9ae849206d6553ac6c0d2c2422e277f93c1f02cc3be28c82b1
run #0: crashed: general protection fault in skb_unlink
run #1: crashed: general protection fault in skb_unlink
run #2: crashed: general protection fault in skb_unlink
run #3: crashed: general protection fault in skb_unlink
run #4: crashed: general protection fault in skb_unlink
run #5: crashed: general protection fault in skb_unlink
run #6: crashed: general protection fault in skb_unlink
run #7: crashed: general protection fault in skb_unlink
run #8: crashed: general protection fault in skb_unlink
run #9: crashed: general protection fault in skb_unlink
run #10: crashed: general protection fault in skb_unlink
run #11: crashed: general protection fault in skb_unlink
run #12: crashed: general protection fault in skb_unlink
run #13: crashed: general protection fault in skb_unlink
run #14: crashed: general protection fault in skb_unlink
run #15: crashed: general protection fault in skb_unlink
run #16: crashed: general protection fault in skb_unlink
run #17: crashed: general protection fault in skb_unlink
run #18: crashed: general protection fault in requeue_rx_msgs
run #19: crashed: general protection fault in skb_unlink
testing current HEAD 4938296e03bd227e5020d63d418956fe52baf97c
testing commit 4938296e03bd227e5020d63d418956fe52baf97c
compiler: gcc version 8.4.1 20210217 (GCC)
kernel signature: 476142cdfc0b8451f754705f01b3a1fc55c80cc5b0c12a942fcb48aa6ecc91a0
all runs: crashed: general protection fault in skb_unlink
revisions tested: 2, total time: 32m8.972697026s (build: 24m35.054615658s, test: 6m28.583251047s)
the crash still happens on HEAD
commit msg: Linux 4.19.198
crash: general protection fault in skb_unlink
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
8021q: adding VLAN 0 to HW filter on device batadv0
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: 1 PID: 6737 Comm: syz-executor.3 Not tainted 4.19.198-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__write_once_size include/linux/compiler.h:288 [inline]
RIP: 0010:__skb_unlink include/linux/skbuff.h:1919 [inline]
RIP: 0010:skb_unlink+0xe7/0x1a0 net/core/skbuff.c:2960
Code: 00 00 49 8d 7d 08 4c 8b 63 08 48 ba 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 f9 48 c7 03 00 00 00 00 48 c1 e9 03 <80> 3c 11 00 75 63 4c 89 e1 4d 89 65 08 48 ba 00 00 00 00 00 fc ff
RSP: 0018:ffff8881dd657838 EFLAGS: 00010002
RAX: 0000000000000286 RBX: ffff8881eea8d480 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 000000000000000f RDI: 0000000000000008
RBP: ffff8881dd657868 R08: ffffed103bc6f285 R09: ffffed103bc6f284
R10: ffffed103bc6f284 R11: ffff8881de379423 R12: 0000000000000000
R13: 0000000000000000 R14: 000000000000000e R15: ffff8881de379420
FS:  00007fb400c53700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d862451140 CR3: 00000001dd997006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kcm_recvmsg+0x3a5/0x5a0 net/kcm/kcmsock.c:1160
 sock_recvmsg_nosec+0x7b/0xd0 net/socket.c:859
 ___sys_recvmsg+0x219/0x500 net/socket.c:2387
 __sys_recvmmsg+0x21d/0x650 net/socket.c:2499
 do_sys_recvmmsg net/socket.c:2575 [inline]
 do_sys_recvmmsg+0x111/0x130 net/socket.c:2564
 __do_sys_recvmmsg net/socket.c:2593 [inline]
 __se_sys_recvmmsg net/socket.c:2589 [inline]
 __x64_sys_recvmmsg+0xb9/0x150 net/socket.c:2589
 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x461fc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb400c531a8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 0000000000461fc9
RDX: 0400000000000310 RSI: 0000000020003540 RDI: 0000000000000005
RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004f7980 R14: 00000000004b412d R15: 00007fb400c536bc
Modules linked in:
---[ end trace ce88ee9982b6bb27 ]---
RIP: 0010:__write_once_size include/linux/compiler.h:288 [inline]
RIP: 0010:__skb_unlink include/linux/skbuff.h:1919 [inline]
RIP: 0010:skb_unlink+0xe7/0x1a0 net/core/skbuff.c:2960
Code: 00 00 49 8d 7d 08 4c 8b 63 08 48 ba 00 00 00 00 00 fc ff df 48 c7 43 08 00 00 00 00 48 89 f9 48 c7 03 00 00 00 00 48 c1 e9 03 <80> 3c 11 00 75 63 4c 89 e1 4d 89 65 08 48 ba 00 00 00 00 00 fc ff
RSP: 0018:ffff8881dd657838 EFLAGS: 00010002
RAX: 0000000000000286 RBX: ffff8881eea8d480 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: 000000000000000f RDI: 0000000000000008
RBP: ffff8881dd657868 R08: ffffed103bc6f285 R09: ffffed103bc6f284
R10: ffffed103bc6f284 R11: ffff8881de379423 R12: 0000000000000000
R13: 0000000000000000 R14: 000000000000000e R15: ffff8881de379420
FS:  00007fb400c53700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d862451140 CR3: 00000001dd997006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400