syzbot


KASAN: null-ptr-deref Read in __tcf_idr_release

Status: upstream: reported C repro on 2020/01/28 14:22
Reported-by: syzbot+c241d0cd220fe5308b96@syzkaller.appspotmail.com
First crash: 1636d, last: 1033d
Fix bisection: failed (error log, bisect log)
  
Fix bisection attempts (21)
Created Duration User Patch Repo Result
2021/10/23 07:31 13m bisect fix linux-4.19.y error job log
2021/09/22 13:55 29m bisect fix linux-4.19.y OK (0) job log log
2021/08/23 12:43 33m bisect fix linux-4.19.y OK (0) job log log
2021/07/24 12:03 27m bisect fix linux-4.19.y OK (0) job log log
2021/06/24 11:36 23m bisect fix linux-4.19.y OK (0) job log log
2021/05/25 05:27 28m bisect fix linux-4.19.y OK (0) job log log
2021/04/25 03:44 28m bisect fix linux-4.19.y OK (0) job log log
2021/03/25 20:02 29m bisect fix linux-4.19.y OK (0) job log log
2021/02/23 19:32 30m bisect fix linux-4.19.y OK (0) job log log
2021/01/22 20:25 30m bisect fix linux-4.19.y OK (0) job log log
2020/12/23 20:00 25m bisect fix linux-4.19.y OK (0) job log log
2020/11/23 19:07 24m bisect fix linux-4.19.y OK (0) job log log
2020/10/24 18:43 23m bisect fix linux-4.19.y OK (0) job log log
2020/09/24 18:02 24m bisect fix linux-4.19.y OK (0) job log log
2020/08/25 17:34 27m bisect fix linux-4.19.y OK (0) job log log
2020/07/26 16:32 25m bisect fix linux-4.19.y OK (0) job log log
2020/06/26 16:08 24m bisect fix linux-4.19.y OK (0) job log log
2020/05/27 15:42 25m bisect fix linux-4.19.y OK (0) job log log
2020/04/27 15:15 26m bisect fix linux-4.19.y OK (0) job log log
2020/03/28 14:51 24m bisect fix linux-4.19.y OK (0) job log log
2020/02/27 14:22 27m bisect fix linux-4.19.y OK (0) job log log

Sample crash report:
audit: type=1400 audit(1580221102.082:35): avc:  denied  { map } for  pid=7987 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(1580221141.532:36): avc:  denied  { map } for  pid=7999 comm="syz-executor463" path="/root/syz-executor463020308" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: null-ptr-deref in __tcf_idr_release+0x92/0xf0 net/sched/act_api.c:139
Read of size 4 at addr 0000000000000010 by task syz-executor463/8009

CPU: 0 PID: 8009 Comm: syz-executor463 Not tainted 4.19.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x199/0x2ba mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 __tcf_idr_release+0x92/0xf0 net/sched/act_api.c:139
 tcf_del_walker net/sched/act_api.c:266 [inline]
 tcf_generic_walker+0x6c6/0xa60 net/sched/act_api.c:292
 tcf_ife_walker+0x1a5/0x2b0 net/sched/act_ife.c:862
 tca_action_flush net/sched/act_api.c:1142 [inline]
 tca_action_gd+0x945/0x1690 net/sched/act_api.c:1248
 tc_ctl_action+0x297/0x43b net/sched/act_api.c:1377
 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:4768
 netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4786
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x53a/0x730 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: 0033:0x446939
Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f47b7a69da8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446939
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00000000006dbc20 R08: 0000000000000008 R09: 0000000000000000
R10: 000000000000000c R11: 0000000000000246 R12: 00000000006dbc2c
R13: 0000000020000400 R14: 00000000004ae7e8 R15: 000000000000002d
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/28 14:22 linux-4.19.y 88d6de67e390 56cd6c9b .config console log report syz C ci2-linux-4-19
* Struck through repros no longer work on HEAD.