KASAN: null-ptr-deref Write in choke_reset

Status: fixed on 2020/06/19 13:29
Reported-by: syzbot+8805bfe94cd9d0b6565c@syzkaller.appspotmail.com
Fix commit: 8738c85c72b3 sch_choke: avoid potential panic in choke_reset()
First crash: 2315d, last: 2285d
Fix bisection: fixed by (bisect log) :
commit 4836eb6b59657a383fa97d3d301da77581ec8f0c
Author: Eric Dumazet <edumazet@google.com>
Date: Sat Apr 25 22:19:51 2020 +0000

  sch_choke: avoid potential panic in choke_reset()

  
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: null-ptr-deref Write in choke_reset 12 syz, C done 236 2291d 2316d 1/1 fixed on 2020/06/13 11:02
upstream KASAN: null-ptr-deref Write in choke_reset 12 syz, C done 1441 2282d 2316d 15/29 fixed on 2020/07/17 17:58

Sample crash report:
audit: type=1400 audit(1589147950.113:8): avc:  denied  { execmem } for  pid=6340 comm="syz-executor271" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
==================================================================
BUG: KASAN: null-ptr-deref in memset include/linux/string.h:332 [inline]
BUG: KASAN: null-ptr-deref in choke_reset+0x1fc/0x330 net/sched/sch_choke.c:330
Write of size 8 at addr           (null) by task syz-executor271/6340

CPU: 0 PID: 6340 Comm: syz-executor271 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 kasan_report_error mm/kasan/report.c:349 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x127/0x2ae mm/kasan/report.c:393
 memset+0x20/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:332 [inline]
 choke_reset+0x1fc/0x330 net/sched/sch_choke.c:330
 qdisc_reset+0x61/0x1e0 net/sched/sch_generic.c:678
 dev_deactivate_queue.constprop.0+0xc5/0x150 net/sched/sch_generic.c:867
 netdev_for_each_tx_queue include/linux/netdevice.h:1970 [inline]
 dev_deactivate_many+0xd6/0x960 net/sched/sch_generic.c:922
 dev_deactivate+0xe2/0x190 net/sched/sch_generic.c:955
 qdisc_graft+0x989/0xcd0 net/sched/sch_api.c:919
 tc_modify_qdisc+0x99e/0x1181 net/sched/sch_api.c:1446
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x440719
RSP: 002b:00007ffd0563b2c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000000440719
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00000000ffffffff R09: 00000000004002c8
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000007166
R13: 0000000000402030 R14: 0000000000000000 R15: 0000000000000000
==================================================================

Crashes (283):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/05/10 22:01 linux-4.14.y ab9dfda23248 8742a2b9 .config console log report syz C ci2-linux-4-14
2020/04/26 09:47 linux-4.14.y 050272a0423e 0ce7569e .config console log report syz C ci2-linux-4-14
2020/04/26 09:27 linux-4.14.y 050272a0423e 0ce7569e .config console log report syz C ci2-linux-4-14
2020/04/20 06:25 linux-4.14.y c10b57a567e4 9f7c6d12 .config console log report syz C ci2-linux-4-14
2020/05/20 03:55 linux-4.14.y ab9dfda23248 6d882fd2 .config console log report ci2-linux-4-14
2020/05/19 23:30 linux-4.14.y ab9dfda23248 6d882fd2 .config console log report ci2-linux-4-14
2020/05/19 17:29 linux-4.14.y ab9dfda23248 6d882fd2 .config console log report ci2-linux-4-14
2020/05/19 16:44 linux-4.14.y ab9dfda23248 6d882fd2 .config console log report ci2-linux-4-14
2020/05/19 12:58 linux-4.14.y ab9dfda23248 6d882fd2 .config console log report ci2-linux-4-14
2020/05/19 10:21 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/19 05:47 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/19 04:43 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/19 01:01 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/18 23:53 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/18 22:44 linux-4.14.y ab9dfda23248 684d3606 .config console log report ci2-linux-4-14
2020/05/18 19:39 linux-4.14.y ab9dfda23248 24d91142 .config console log report ci2-linux-4-14
2020/05/18 12:24 linux-4.14.y ab9dfda23248 24d91142 .config console log report ci2-linux-4-14
2020/05/18 11:18 linux-4.14.y ab9dfda23248 24d91142 .config console log report ci2-linux-4-14
2020/05/18 08:57 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/18 04:05 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/18 00:05 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 22:37 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 21:02 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 19:23 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 17:13 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 14:55 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 12:29 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 10:56 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 05:36 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 02:39 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 01:07 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/17 01:01 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 23:36 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 22:08 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 14:08 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 11:51 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 10:25 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 09:16 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 04:38 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 02:36 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/16 00:35 linux-4.14.y ab9dfda23248 37bccd4e .config console log report ci2-linux-4-14
2020/05/15 13:03 linux-4.14.y ab9dfda23248 d7f9fffa .config console log report ci2-linux-4-14
2020/05/15 11:40 linux-4.14.y ab9dfda23248 2d572622 .config console log report ci2-linux-4-14
2020/05/15 09:29 linux-4.14.y ab9dfda23248 2d572622 .config console log report ci2-linux-4-14
2020/05/15 07:20 linux-4.14.y ab9dfda23248 2d572622 .config console log report ci2-linux-4-14
2020/05/15 05:48 linux-4.14.y ab9dfda23248 2d572622 .config console log report ci2-linux-4-14
2020/05/15 00:52 linux-4.14.y ab9dfda23248 2d572622 .config console log report ci2-linux-4-14
2020/04/20 06:08 linux-4.14.y c10b57a567e4 9f7c6d12 .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.