syzbot


KASAN: slab-out-of-bounds Read in bitmap_ipmac_ext_cleanup

Status: fixed on 2020/03/17 22:09
Subsystems: netfilter
[Documentation on labels]
Reported-by: syzbot+c400f7b04cadb5df6ea7@syzkaller.appspotmail.com
Fix commit: 32c72165dbd0 netfilter: ipset: use bitmap infrastructure completely
First crash: 1641d, last: 1625d
Cause bisection: introduced by (bisect log) [merge commit]:
commit fa8043017cf83427c7e3d7d8defe2c2133edffea
Author: David S. Miller <davem@davemloft.net>
Date: Fri Jul 5 22:22:28 2019 +0000

  Merge branch 'hsr-bug-fixes'

Crash: general protection fault in send_hsr_supervision_frame (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 32c72165dbd0e246e69d16a3ad348a4851afd415
Author: Kadlecsik Jรณzsef <kadlec@blackhole.kfki.hu>
Date: Sun Jan 19 21:06:49 2020 +0000

  netfilter: ipset: use bitmap infrastructure completely

  
Discussions (1)
Title Replies (including bot) Last reply
KASAN: slab-out-of-bounds Read in bitmap_ipmac_ext_cleanup 0 (2) 2020/03/15 21:26

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
BUG: KASAN: slab-out-of-bounds in bitmap_ipmac_ext_cleanup+0xd8/0x290 net/netfilter/ipset/ip_set_bitmap_gen.h:51
Read of size 8 at addr ffff888096095e00 by task syz-executor426/9689

CPU: 0 PID: 9689 Comm: syz-executor426 Not tainted 5.5.0-rc7-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
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
 bitmap_ipmac_ext_cleanup+0xd8/0x290 net/netfilter/ipset/ip_set_bitmap_gen.h:51
 bitmap_ipmac_destroy+0x180/0x1d0 net/netfilter/ipset/ip_set_bitmap_gen.h:64
 ip_set_create+0xe47/0x1500 net/netfilter/ipset/ip_set_core.c:1165
 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x58c/0x7d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:659
 ____sys_sendmsg+0x753/0x880 net/socket.c:2330
 ___sys_sendmsg+0x100/0x170 net/socket.c:2384
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2424
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4413f9
Code: e8 fc ab 02 00 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd6f5c81a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004413f9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00000000000180e7 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402220
R13: 00000000004022b0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 9689:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:561 [inline]
 kzalloc include/linux/slab.h:670 [inline]
 ip_set_alloc+0x38/0x5e net/netfilter/ipset/ip_set_core.c:255
 init_map_ipmac net/netfilter/ipset/ip_set_bitmap_ipmac.c:302 [inline]
 bitmap_ipmac_create+0x4e8/0xa00 net/netfilter/ipset/ip_set_bitmap_ipmac.c:365
 ip_set_create+0x6f1/0x1500 net/netfilter/ipset/ip_set_core.c:1111
 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x58c/0x7d0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:659
 ____sys_sendmsg+0x753/0x880 net/socket.c:2330
 ___sys_sendmsg+0x100/0x170 net/socket.c:2384
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2424
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff888096094000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 7680 bytes inside of
 8192-byte region [ffff888096094000, ffff888096096000)
The buggy address belongs to the page:
page:ffffea0002582500 refcount:1 mapcount:0 mapping:ffff8880aa4021c0 index:0x0 compound_mapcount: 0
raw: 00fffe0000010200 ffffea0002761e08 ffff8880aa401b48 ffff8880aa4021c0
raw: 0000000000000000 ffff888096094000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888096095d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888096095d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888096095e00: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff888096095e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888096095f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/24 15:53 upstream 4703d9119972 2e95ab33 .config console log report syz C ci-upstream-kasan-gce
2020/01/21 19:00 upstream d96d875ef5dd 8eda0b95 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/01/21 12:57 upstream d96d875ef5dd 8eda0b95 .config console log report syz C ci-upstream-kasan-gce-root
2020/01/20 20:24 upstream def9d2780727 d2557fb5 .config console log report syz C ci-upstream-kasan-gce
2020/01/24 13:30 upstream 4703d9119972 2e95ab33 .config console log report syz C ci-upstream-kasan-gce-386
2020/01/24 13:07 net-old 61678d28d4a4 2e95ab33 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/01/20 01:12 net-old 09d4f10a5e78 0342f8c7 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/01/24 13:07 net-next-old 9bbc8be29d66 2e95ab33 .config console log report syz C ci-upstream-net-kasan-gce
2020/02/04 21:46 linux-next 2747d5fdab78 93e5e335 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/01/24 12:36 upstream 4703d9119972 2e95ab33 .config console log report ci-upstream-kasan-gce-selinux-root
2020/01/24 12:30 upstream 4703d9119972 2e95ab33 .config console log report ci-upstream-kasan-gce-root
2020/01/24 12:29 upstream 4703d9119972 2e95ab33 .config console log report ci-upstream-kasan-gce-root
2020/01/24 12:29 upstream 4703d9119972 2e95ab33 .config console log report ci-upstream-kasan-gce
2020/01/24 12:49 net-next-old 9bbc8be29d66 2e95ab33 .config console log report ci-upstream-net-kasan-gce
2020/01/24 12:29 net-next-old 9bbc8be29d66 2e95ab33 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.