syzbot


general protection fault in skb_segment

Status: fixed on 2018/01/29 03:39
Reported-by: syzbot+fee64147a25aecd48055@syzkaller.appspotmail.com
Fix commit: 121d57af308d gso: validate gso_type in GSO handlers
First crash: 1687d, last: 1674d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 general protection fault in skb_segment 1 34d 34d 0/1 upstream: reported on 2022/07/05 17:51
upstream general protection fault in skb_segment (2) 1 539d 539d 0/23 auto-closed as invalid on 2021/05/17 11:26

Sample crash report:
device syz0 entered promiscuous mode
audit: type=1400 audit(1515254229.466:10): avc:  denied  { net_raw } for  pid=3495 comm="syzkaller190556" capability=13  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1515254229.468:11): avc:  denied  { net_admin } for  pid=3495 comm="syzkaller190556" capability=12  scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3495 Comm: syzkaller190556 Not tainted 4.15.0-rc6+ #249
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:skb_segment+0x67c/0x3020 net/core/skbuff.c:3567
RSP: 0018:ffff8801bfba6ab0 EFLAGS: 00010202
RAX: 0000000000000010 RBX: 0000000000000000 RCX: ffffffff8430c8d7
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000080
RBP: ffff8801bfba6d68 R08: 0000000000000020 R09: 0000000000000002
R10: ffff8801bfba6df0 R11: 0000000000000000 R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801bfc6dcc0
FS:  00000000008d0880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002355000 CR3: 00000001c02f8004 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sctp_gso_segment+0x222/0x8b0 net/sctp/offload.c:72
 inet_gso_segment+0x61e/0x11e0 net/ipv4/af_inet.c:1274
 skb_mac_gso_segment+0x34e/0x670 net/core/dev.c:2731
 __skb_gso_segment+0x363/0x800 net/core/dev.c:2804
 skb_gso_segment include/linux/netdevice.h:3993 [inline]
 validate_xmit_skb+0x4ba/0xb30 net/core/dev.c:3057
 validate_xmit_skb_list+0xb7/0x120 net/core/dev.c:3108
 sch_direct_xmit+0x3b6/0x6d0 net/sched/sch_generic.c:182
 __dev_xmit_skb net/core/dev.c:3189 [inline]
 __dev_queue_xmit+0x1ce2/0x2920 net/core/dev.c:3456
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3521
 packet_snd net/packet/af_packet.c:2943 [inline]
 packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2968
 sock_sendmsg_nosec net/socket.c:636 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:646
 sock_write_iter+0x31a/0x5d0 net/socket.c:915
 call_write_iter include/linux/fs.h:1772 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x684/0x970 fs/read_write.c:482
 vfs_write+0x189/0x510 fs/read_write.c:544
 SYSC_write fs/read_write.c:589 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:581
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x444c09
RSP: 002b:00000000007eff48 EFLAGS: 00000297 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffe09f4bb20 RCX: 0000000000444c09
RDX: 000000000000002a RSI: 0000000020634000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000297 R12: 0000000000402800
R13: 0000000000402890 R14: 0000000000000000 R15: 0000000000000000
Code: 8d 14 fe ff ff 39 8d 38 fe ff ff 0f 8f a5 00 00 00 e8 a9 4e 3f fd 48 8b 85 48 fe ff ff 48 8d b8 80 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 14 28 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 
RIP: skb_segment+0x67c/0x3020 net/core/skbuff.c:3567 RSP: ffff8801bfba6ab0
---[ end trace 3bff400af13fd076 ]---

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2018/01/06 15:58 upstream 89876f275e8d 053171ea .config log report syz C
ci-upstream-kasan-gce-386 2018/01/06 15:58 upstream 89876f275e8d 053171ea .config log report syz C
ci-upstream-mmots-kasan-gce 2018/01/07 03:08 mmots 69eed2290e1d 19c05fff .config log report syz C
ci-upstream-next-kasan-gce 2018/01/06 15:58 linux-next 990b6a07d18c 053171ea .config log report syz C
ci-upstream-next-kasan-gce 2017/12/26 02:40 linux-next 0e08c463db38 73aba437 .config log report syz C
ci-upstream-mmots-kasan-gce 2017/12/25 17:38 mmots 37759fa6d0fa 73aba437 .config log report syz C
ci-upstream-net-kasan-gce 2018/01/08 13:12 net-next f66faae2f80a 93b4c6f1 .config log report