syzbot


general protection fault in packet_lookup_frame

Status: fixed on 2019/12/04 13:46
Reported-by: syzbot+497663e373e2a355e86b@syzkaller.appspotmail.com
Fix commit: 5ac73816dda7 net/packet: fix race in tpacket_snd()
First crash: 1273d, last: 1273d

Fix bisection: fixed by (bisect log) :
commit 5ac73816dda7d2d33ef89177b3d095b3cf5777fb
Author: Eric Dumazet <edumazet@google.com>
Date: Wed Aug 14 09:11:57 2019 +0000

  net/packet: fix race in tpacket_snd()

similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 general protection fault in packet_lookup_frame C done 1 1273d 1273d 1/1 fixed on 2019/12/04 13:46
upstream general protection fault in packet_lookup_frame C done 7 1273d 1273d 13/24 fixed on 2019/09/06 20:45

Sample crash report:
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: 7387 Comm: syz-executor026 Not tainted 4.14.138 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809620a340 task.stack: ffff888092eb0000
RIP: 0010:packet_lookup_frame+0x8d/0x240 net/packet/af_packet.c:515
RSP: 0018:ffff888092eb77d0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88809617dad0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff11012c2fb5a RDI: ffff88809617dadc
RBP: ffff888092eb7800 R08: ffff88809620a340 R09: 0000000000000001
R10: 0000000000000000 R11: ffff88809620a340 R12: 0000000000000000
R13: 0000000000000001 R14: ffff88809617d580 R15: 0000000000000000
FS:  00007f28d9877700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f28d9897e78 CR3: 00000000a95ab000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 packet_current_frame net/packet/af_packet.c:528 [inline]
 tpacket_snd net/packet/af_packet.c:2703 [inline]
 packet_sendmsg+0x520/0x5a10 net/packet/af_packet.c:3009
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xce/0x110 net/socket.c:656
 ___sys_sendmsg+0x349/0x840 net/socket.c:2062
 __sys_sendmmsg+0x152/0x3a0 net/socket.c:2152
 SYSC_sendmmsg net/socket.c:2183 [inline]
 SyS_sendmmsg+0x35/0x60 net/socket.c:2178
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4479b9
RSP: 002b:00007f28d9876da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 00000000004479b9
RDX: 0400000000000328 RSI: 0000000020008a80 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f28d9877700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 0000315f6576616c R14: 735f656764697262 R15: 00000000006dcc3c
Code: 48 c1 ee 03 f7 73 0c 80 3c 0e 00 0f 85 9e 01 00 00 48 8b 0b 89 c0 4c 8d 24 c1 48 b8 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 <80> 3c 01 00 0f 85 93 01 00 00 48 8d 7b 10 4d 8b 3c 24 48 b9 00 
RIP: packet_lookup_frame+0x8d/0x240 net/packet/af_packet.c:515 RSP: ffff888092eb77d0
---[ end trace b36cf0de1cad273b ]---

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2019/08/14 02:45 linux-4.14.y 3ffe1e79c174 ef801a3e .config console log report syz C
* Struck through repros no longer work on HEAD.