KASAN: use-after-free Read in bitmap_ipmac_ext_cleanup

KASAN: use-after-free Read in bitmap_ipmac_ext_cleanup

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    7f013ede Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11c41495e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=66d8660c57ff3c98
dashboard link: https://syzkaller.appspot.com/bug?extid=33fc3ad6fa11675e1a7e
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15102cc9e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17e38faee00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+33fc3ad6fa11675e1a7e@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
BUG: KASAN: use-after-free in bitmap_ipmac_ext_cleanup+0xd8/0x290 net/netfilter/ipset/ip_set_bitmap_gen.h:51
Read of size 8 at addr ffff8880a2ac3a40 by task syz-executor324/9651

CPU: 0 PID: 9651 Comm: syz-executor324 Not tainted 5.5.0-rc5-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+0x17c/0x1d0 net/netfilter/ipset/ip_set_bitmap_gen.h:65
 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+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x442239
Code: e8 6c aa 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:00007ffc7958b8c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000442239
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 0000000000016edc R08: 00000000004030f0 R09: 00000000004030f0
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000403060
R13: 00000000004030f0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 9651:
 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+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9651:
 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
 kvfree+0x61/0x70 mm/util.c:603
 ip_set_free+0x16/0x20 net/netfilter/ipset/ip_set_core.c:276
 bitmap_ipmac_destroy+0xae/0x1d0 net/netfilter/ipset/ip_set_bitmap_gen.h:63
 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+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 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 ffff8880a2ac3a40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8880a2ac3a40, ffff8880a2ac3a60)
The buggy address belongs to the page:
page:ffffea00028ab0c0 refcount:1 mapcount:0 mapping:ffff8880aa4001c0 index:0xffff8880a2ac3fc1
raw: 00fffe0000000200 ffffea000293f948 ffffea00025764c8 ffff8880aa4001c0
raw: ffff8880a2ac3fc1 ffff8880a2ac3000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a2ac3900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a2ac3980: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8880a2ac3a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                                           ^
 ffff8880a2ac3a80: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff8880a2ac3b00: fb fb fb fb fc fc fc fc 00 03 fc fc fc fc fc fc
==================================================================


---
This bug is generated by a bot. It may contain errors.
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Re: KASAN: use-after-free Read in bitmap_ipmac_ext_cleanup

[syzbot]

syzbot has bisected this bug to:

commit ff95bf28c23490584b9d75913a520bb7bb1f2ecb
Author: Po-Hsu Lin <po-hsu.lin@canonical.com>
Date:   Mon Jul 1 04:40:31 2019 +0000

    selftests/net: skip psock_tpacket test if KALLSYMS was not enabled

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17e2e966e00000
start commit:   8f8972a3 Merge tag 'mtd/fixes-for-5.5-rc7' of git://git.ke..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=1412e966e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=1012e966e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
dashboard link: https://syzkaller.appspot.com/bug?extid=33fc3ad6fa11675e1a7e
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15982cc9e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11be38d6e00000

Reported-by: syzbot+33fc3ad6fa11675e1a7e@syzkaller.appspotmail.com
Fixes: ff95bf28c234 ("selftests/net: skip psock_tpacket test if KALLSYMS was not enabled")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: KASAN: use-after-free Read in bitmap_ipmac_ext_cleanup

[syzbot]

syzbot suspects this bug was fixed by commit:

commit 32c72165dbd0e246e69d16a3ad348a4851afd415
Author: Kadlecsik József <kadlec@blackhole.kfki.hu>
Date:   Sun Jan 19 21:06:49 2020 +0000

    netfilter: ipset: use bitmap infrastructure completely

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=13435a7ee00000
start commit:   8f8972a3 Merge tag 'mtd/fixes-for-5.5-rc7' of git://git.ke..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=d9290aeb7e6cf1c4
dashboard link: https://syzkaller.appspot.com/bug?extid=33fc3ad6fa11675e1a7e
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15982cc9e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11be38d6e00000

If the result looks correct, please mark the bug fixed by replying with:

#syz fix: netfilter: ipset: use bitmap infrastructure completely

For information about bisection process see: https://goo.gl/tpsmEJ#bisection