KASAN: use-after-free Read in bitmap_port_ext_cleanup

KASAN: use-after-free Read in bitmap_port_ext_cleanup

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    b07f636f Merge tag 'tpmdd-next-20200108' of git://git.infr..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16c03259e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=18698c0c240ba616
dashboard link: https://syzkaller.appspot.com/bug?extid=4c3cc6dbe7259dbf9054
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10c365c6e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117df9e1e00000

The bug was bisected to:

commit b9a1e627405d68d475a3c1f35e685ccfb5bbe668
Author: Cong Wang <xiyou.wangcong@gmail.com>
Date:   Thu Jul 4 00:21:13 2019 +0000

     hsr: implement dellink to clean up resources

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=118759e1e00000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=138759e1e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=158759e1e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com
Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources")

==================================================================
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_port_ext_cleanup+0xe6/0x2a0  
net/netfilter/ipset/ip_set_bitmap_gen.h:51
Read of size 8 at addr ffff8880a87a47c0 by task syz-executor559/9563

CPU: 0 PID: 9563 Comm: syz-executor559 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_port_ext_cleanup+0xe6/0x2a0  
net/netfilter/ipset/ip_set_bitmap_gen.h:51
  bitmap_port_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+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
  __compat_sys_sendmsg net/compat.c:642 [inline]
  __do_compat_sys_sendmsg net/compat.c:649 [inline]
  __se_compat_sys_sendmsg net/compat.c:646 [inline]
  __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:646
  do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
  do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f8ea39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c  
24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90  
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffc15a2c EFLAGS: 00000202 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020001080
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000ffc15b44
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 9563:
  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_port net/netfilter/ipset/ip_set_bitmap_port.c:234 [inline]
  bitmap_port_create+0x3dc/0x7c0 net/netfilter/ipset/ip_set_bitmap_port.c:276
  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
  __compat_sys_sendmsg net/compat.c:642 [inline]
  __do_compat_sys_sendmsg net/compat.c:649 [inline]
  __se_compat_sys_sendmsg net/compat.c:646 [inline]
  __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:646
  do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
  do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 9563:
  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_port_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+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
  __compat_sys_sendmsg net/compat.c:642 [inline]
  __do_compat_sys_sendmsg net/compat.c:649 [inline]
  __se_compat_sys_sendmsg net/compat.c:646 [inline]
  __ia32_compat_sys_sendmsg+0x7a/0xb0 net/compat.c:646
  do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
  do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
  entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff8880a87a47c0
  which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
  32-byte region [ffff8880a87a47c0, ffff8880a87a47e0)
The buggy address belongs to the page:
page:ffffea0002a1e900 refcount:1 mapcount:0 mapping:ffff8880aa4001c0  
index:0xffff8880a87a4fc1
raw: 00fffe0000000200 ffffea0002a25108 ffffea00027a3188 ffff8880aa4001c0
raw: ffff8880a87a4fc1 ffff8880a87a4000 000000010000002e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8880a87a4680: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
  ffff8880a87a4700: fb fb fb fb fc fc fc fc 00 05 fc fc fc fc fc fc
> ffff8880a87a4780: 00 05 fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                                            ^
  ffff8880a87a4800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
  ffff8880a87a4880: 06 fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
==================================================================


---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

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

[Cong Wang]

On Fri, Jan 10, 2020 at 10:44 AM syzbot
<syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    b07f636f Merge tag 'tpmdd-next-20200108' of git://git.infr..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16c03259e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=18698c0c240ba616
> dashboard link: https://syzkaller.appspot.com/bug?extid=4c3cc6dbe7259dbf9054
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> userspace arch: i386
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10c365c6e00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117df9e1e00000
>
> The bug was bisected to:
>
> commit b9a1e627405d68d475a3c1f35e685ccfb5bbe668
> Author: Cong Wang <xiyou.wangcong@gmail.com>
> Date:   Thu Jul 4 00:21:13 2019 +0000
>
>      hsr: implement dellink to clean up resources
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=118759e1e00000
> final crash:    https://syzkaller.appspot.com/x/report.txt?x=138759e1e00000
> console output: https://syzkaller.appspot.com/x/log.txt?x=158759e1e00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com
> Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources")
>
> ==================================================================
> 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_port_ext_cleanup+0xe6/0x2a0
> net/netfilter/ipset/ip_set_bitmap_gen.h:51
> Read of size 8 at addr ffff8880a87a47c0 by task syz-executor559/9563
>
> CPU: 0 PID: 9563 Comm: syz-executor559 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_port_ext_cleanup+0xe6/0x2a0

map->members is freed by ip_set_free() right before using it in
mtype_ext_cleanup() again. So I think probably we just have to
move it down:

diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h
b/net/netfilter/ipset/ip_set_bitmap_gen.h
index 1abd6f0dc227..077a2cb65fcb 100644
--- a/net/netfilter/ipset/ip_set_bitmap_gen.h
+++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
@@ -60,9 +60,9 @@ mtype_destroy(struct ip_set *set)
        if (SET_WITH_TIMEOUT(set))
                del_timer_sync(&map->gc);

-       ip_set_free(map->members);
        if (set->dsize && set->extensions & IPSET_EXT_DESTROY)
                mtype_ext_cleanup(set);
+       ip_set_free(map->members);
        ip_set_free(map);

        set->data = NULL;

Thanks.

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

[Kadlecsik József]

Hi,

On Fri, 10 Jan 2020, Cong Wang wrote:

> On Fri, Jan 10, 2020 at 10:44 AM syzbot
> <syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com> wrote:
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:    b07f636f Merge tag 'tpmdd-next-20200108' of git://git.infr..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16c03259e00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=18698c0c240ba616
> > dashboard link: https://syzkaller.appspot.com/bug?extid=4c3cc6dbe7259dbf9054
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > userspace arch: i386
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10c365c6e00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117df9e1e00000
> >
> > The bug was bisected to:
> >
> > commit b9a1e627405d68d475a3c1f35e685ccfb5bbe668
> > Author: Cong Wang <xiyou.wangcong@gmail.com>
> > Date:   Thu Jul 4 00:21:13 2019 +0000
> >
> >      hsr: implement dellink to clean up resources
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=118759e1e00000
> > final crash:    https://syzkaller.appspot.com/x/report.txt?x=138759e1e00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=158759e1e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+4c3cc6dbe7259dbf9054@syzkaller.appspotmail.com
> > Fixes: b9a1e627405d ("hsr: implement dellink to clean up resources")
> >
> > ==================================================================
> > 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_port_ext_cleanup+0xe6/0x2a0
> > net/netfilter/ipset/ip_set_bitmap_gen.h:51
> > Read of size 8 at addr ffff8880a87a47c0 by task syz-executor559/9563
> >
> > CPU: 0 PID: 9563 Comm: syz-executor559 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_port_ext_cleanup+0xe6/0x2a0
> 
> map->members is freed by ip_set_free() right before using it in
> mtype_ext_cleanup() again. So I think probably we just have to
> move it down:

Yes, exactly. As you suggested, could you submit a patch?

Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>

Best regards,
Jozsef
 
> diff --git a/net/netfilter/ipset/ip_set_bitmap_gen.h
> b/net/netfilter/ipset/ip_set_bitmap_gen.h
> index 1abd6f0dc227..077a2cb65fcb 100644
> --- a/net/netfilter/ipset/ip_set_bitmap_gen.h
> +++ b/net/netfilter/ipset/ip_set_bitmap_gen.h
> @@ -60,9 +60,9 @@ mtype_destroy(struct ip_set *set)
>         if (SET_WITH_TIMEOUT(set))
>                 del_timer_sync(&map->gc);
> 
> -       ip_set_free(map->members);
>         if (set->dsize && set->extensions & IPSET_EXT_DESTROY)
>                 mtype_ext_cleanup(set);
> +       ip_set_free(map->members);
>         ip_set_free(map);
> 
>         set->data = NULL;
> 
> Thanks.
> 

-
E-mail  : kadlec@blackhole.kfki.hu, kadlecsik.jozsef@wigner.mta.hu
PGP key : http://www.kfki.hu/~kadlec/pgp_public_key.txt
Address : Wigner Research Centre for Physics
          H-1525 Budapest 114, POB. 49, Hungary