syzbot


BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass

Status: fixed on 2019/12/09 13:28
Reported-by: syzbot+6ccecf683a047d7bcd97@syzkaller.appspotmail.com
Fix commit: 07f7ec87b5f6 net_sched: check cops->tcf_block in tc_bind_tclass()
First crash: 1664d, last: 1645d
Fix bisection: fixed by (bisect log) :
commit 07f7ec87b5f6e1c9d954e967e971efa696ecb018
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date: Sun Sep 8 19:11:23 2019 +0000

  net_sched: check cops->tcf_block in tc_bind_tclass()

  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass C done 14 1624d 1664d 1/1 fixed on 2019/12/12 17:16
upstream BUG: unable to handle kernel NULL pointer dereference in tc_bind_tclass net C done 61 1655d 1663d 13/26 fixed on 2019/10/09 10:54

Sample crash report:
audit: type=1400 audit(1569371496.561:36): avc:  denied  { map } for  pid=7406 comm="syz-executor160" path="/root/syz-executor160001217" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
IPVS: ftp: loaded support on port[0] = 21
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 93f3c067 P4D 93f3c067 PUD 831f8067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 7407 Comm: syz-executor160 Not tainted 4.19.75 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff8880941e74d8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff87e1fe00 RCX: ffffffff857e91e4
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88808182c3c0
RBP: ffff8880941e75d0 R08: ffff88808f7ba100 R09: ffff8880941e7658
R10: ffffed101283ced9 R11: ffff8880941e76cf R12: ffff8880941e75a8
R13: ffff88808182c3c0 R14: 0000000000000001 R15: ffffffff87e1fe00
FS:  000055555560d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000093e78000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tc_bind_tclass+0x13c/0x490 net/sched/sch_api.c:1834
 tc_ctl_tclass+0xaa9/0xc60 net/sched/sch_api.c:1968
 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4747
 netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4765
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x537/0x720 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:632
 ___sys_sendmsg+0x803/0x920 net/socket.c:2115
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2153
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440d89
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 7b 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc2e7aaa98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004a26d0 RCX: 0000000000440d89
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000004a26d0 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000120080522 R11: 0000000000000246 R12: 0000000000402290
R13: 0000000000402320 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 82cf4cece8f6255b ]---
RIP: 0010:          (null)
Code: Bad RIP value.
RSP: 0018:ffff8880941e74d8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff87e1fe00 RCX: ffffffff857e91e4
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88808182c3c0
RBP: ffff8880941e75d0 R08: ffff88808f7ba100 R09: ffff8880941e7658
R10: ffffed101283ced9 R11: ffff8880941e76cf R12: ffff8880941e75a8
R13: ffff88808182c3c0 R14: 0000000000000001 R15: ffffffff87e1fe00
FS:  000055555560d880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000093e78000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/25 00:35 linux-4.19.y d573e8a79f70 e38a6630 .config console log report syz C ci2-linux-4-19
2019/09/13 04:01 linux-4.19.y ee809c7e0895 40fa42bc .config console log report syz C ci2-linux-4-19
2019/09/06 23:28 linux-4.19.y 0fed55c248d9 acb5b744 .config console log report syz ci2-linux-4-19
2019/09/06 22:58 linux-4.19.y 0fed55c248d9 acb5b744 .config console log report syz ci2-linux-4-19
2019/09/06 22:12 linux-4.19.y 0fed55c248d9 acb5b744 .config console log report syz ci2-linux-4-19
2019/09/06 21:44 linux-4.19.y 0fed55c248d9 acb5b744 .config console log report syz ci2-linux-4-19
2019/09/06 20:37 linux-4.19.y 0fed55c248d9 acb5b744 .config console log report syz ci2-linux-4-19
2019/09/25 16:29 linux-4.19.y d573e8a79f70 a3355dba .config console log report ci2-linux-4-19
2019/09/25 05:16 linux-4.19.y d573e8a79f70 e38a6630 .config console log report ci2-linux-4-19
2019/09/19 13:17 linux-4.19.y dbc29aff8d04 eb940044 .config console log report ci2-linux-4-19
2019/09/19 11:22 linux-4.19.y dbc29aff8d04 eb940044 .config console log report ci2-linux-4-19
2019/09/17 21:02 linux-4.19.y db2d0b7c1dde 13dcda9b .config console log report ci2-linux-4-19
2019/09/17 20:28 linux-4.19.y db2d0b7c1dde 13dcda9b .config console log report ci2-linux-4-19
2019/09/17 11:03 linux-4.19.y db2d0b7c1dde 51ca0454 .config console log report ci2-linux-4-19
2019/09/17 10:53 linux-4.19.y db2d0b7c1dde 51ca0454 .config console log report ci2-linux-4-19
2019/09/17 10:50 linux-4.19.y db2d0b7c1dde 51ca0454 .config console log report ci2-linux-4-19
2019/09/16 19:15 linux-4.19.y db2d0b7c1dde 55c50e70 .config console log report ci2-linux-4-19
2019/09/13 03:26 linux-4.19.y ee809c7e0895 40fa42bc .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.