syzbot


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

Status: fixed on 2020/03/17 22:09
Subsystems: netfilter
[Documentation on labels]
Reported-by: syzbot+6491ea8f6dddbf04930e@syzkaller.appspotmail.com
Fix commit: 32c72165dbd0 netfilter: ipset: use bitmap infrastructure completely
First crash: 1618d, last: 1602d
Cause bisection: introduced by (bisect log) :
commit d68dbb0c9ac8b1ff52eb09aa58ce6358400fa939
Author: Christian Brauner <christian@brauner.io>
Date: Thu Jun 20 23:26:35 2019 +0000

  arch: handle arches who do not yet define clone3

Crash: general protection fault in batadv_iv_ogm_queue_add (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_ip_ext_cleanup 2 (5) 2020/03/16 02:40

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_ip_ext_cleanup+0xd8/0x290 net/netfilter/ipset/ip_set_bitmap_gen.h:51
Read of size 8 at addr ffff888099964d00 by task syz-executor196/10849

CPU: 1 PID: 10849 Comm: syz-executor196 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_ip_ext_cleanup+0xd8/0x290 net/netfilter/ipset/ip_set_bitmap_gen.h:51
 bitmap_ip_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: 0033:0x441459
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:00007ffe7d1caa58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441459
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 000000000001a0bf R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402280
R13: 0000000000402310 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 10849:
 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_ip net/netfilter/ipset/ip_set_bitmap_ip.c:223 [inline]
 bitmap_ip_create+0x6ec/0xc20 net/netfilter/ipset/ip_set_bitmap_ip.c:327
 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 10611:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 tomoyo_add_entry security/tomoyo/common.c:2045 [inline]
 tomoyo_supervisor+0xc2c/0xef0 security/tomoyo/common.c:2103
 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
 tomoyo_path_permission security/tomoyo/file.c:587 [inline]
 tomoyo_path_permission+0x263/0x360 security/tomoyo/file.c:573
 tomoyo_path_perm+0x318/0x430 security/tomoyo/file.c:838
 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129
 security_inode_getattr+0xf2/0x150 security/security.c:1222
 vfs_getattr+0x25/0x70 fs/stat.c:115
 vfs_statx+0x157/0x200 fs/stat.c:191
 vfs_stat include/linux/fs.h:3249 [inline]
 __do_sys_newstat+0xa4/0x130 fs/stat.c:341
 __se_sys_newstat fs/stat.c:337 [inline]
 __x64_sys_newstat+0x54/0x80 fs/stat.c:337
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888099964d00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff888099964d00, ffff888099964d20)
The buggy address belongs to the page:
page:ffffea0002665900 refcount:1 mapcount:0 mapping:ffff8880aa4001c0 index:0xffff888099964fc1
raw: 00fffe0000000200 ffffea0002755388 ffffea00026be148 ffff8880aa4001c0
raw: ffff888099964fc1 ffff888099964000 0000000100000029 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888099964c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff888099964c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff888099964d00: 04 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                   ^
 ffff888099964d80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff888099964e00: fb fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc
==================================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/21 04:34 upstream d96d875ef5dd d2557fb5 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/01/20 18:33 upstream def9d2780727 d2557fb5 .config console log report syz C ci-upstream-kasan-gce-root
2020/01/20 09:38 upstream def9d2780727 0342f8c7 .config console log report syz C ci-upstream-kasan-gce
2020/01/19 20:24 net-old 09d4f10a5e78 0342f8c7 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/02/02 12:29 linux-next 2747d5fdab78 2274ad39 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/02/04 23:39 linux-next 2747d5fdab78 93e5e335 .config console log report ci-upstream-linux-next-kasan-gce-root
2020/02/03 12:55 linux-next 2747d5fdab78 93e5e335 .config console log report ci-upstream-linux-next-kasan-gce-root
2020/02/03 10:23 linux-next 2747d5fdab78 93e5e335 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.