lkml.org 
[lkml]   [2020]   [Jul]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2] net: ipv6: fix use-after-free Read in __xfrm6_tunnel_spi_lookup
__xfrm_tunnel_spi_check used xfrm6_tunnel_spi_has_byspi
which returns spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE.
whereas xfrm6_tunnel_spi_hash_byaddr makes a call to
ipv6_addr_hash.

netdevsim netdevsim0 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
==================================================================
BUG: KASAN: use-after-free in __xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79
Read of size 8 at addr ffff8880934578a8 by task syz-executor437/6811
CPU: 0 PID: 6811 Comm: syz-executor437 Not tainted 5.8.0-rc5-next-20200715-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+0x18f/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
__xfrm6_tunnel_spi_lookup+0x3a9/0x3b0 net/ipv6/xfrm6_tunnel.c:79
xfrm6_tunnel_spi_lookup+0x8a/0x1d0 net/ipv6/xfrm6_tunnel.c:95
xfrmi6_rcv_tunnel+0xb9/0x100 net/xfrm/xfrm_interface.c:824
tunnel6_rcv+0xef/0x2b0 net/ipv6/tunnel6.c:148
ip6_protocol_deliver_rcu+0x2e8/0x1670 net/ipv6/ip6_input.c:433
ip6_input_finish+0x7f/0x160 net/ipv6/ip6_input.c:474
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ip6_input+0x9c/0xd0 net/ipv6/ip6_input.c:483
dst_input include/net/dst.h:449 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
NF_HOOK include/linux/netfilter.h:301 [inline]
ipv6_rcv+0x28e/0x3c0 net/ipv6/ip6_input.c:307
__netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5287
__netif_receive_skb+0x27/0x1c0 net/core/dev.c:5401
netif_receive_skb_internal net/core/dev.c:5503 [inline]
netif_receive_skb+0x159/0x990 net/core/dev.c:5562
tun_rx_batched.isra.0+0x460/0x720 drivers/net/tun.c:1518
tun_get_user+0x23b2/0x35b0 drivers/net/tun.c:1972
tun_chr_write_iter+0xba/0x151 drivers/net/tun.c:2001
call_write_iter include/linux/fs.h:1879 [inline]
new_sync_write+0x422/0x650 fs/read_write.c:515
vfs_write+0x59d/0x6b0 fs/read_write.c:595
ksys_write+0x12d/0x250 fs/read_write.c:648
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x403d50
Code: Bad RIP value.
RSP: 002b:00007ffe8fe93368 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000403d50
RDX: 000000000000005e RSI: 00000000200007c0 RDI: 00000000000000f0
RBP: 00007ffe8fe93390 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8fe93380
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Allocated by task 6811:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
__do_kmalloc mm/slab.c:3655 [inline]
__kmalloc+0x1a8/0x320 mm/slab.c:3664
kmalloc include/linux/slab.h:559 [inline]
kzalloc include/linux/slab.h:666 [inline]
tomoyo_init_log+0x1335/0x1e50 security/tomoyo/audit.c:275
tomoyo_supervisor+0x32f/0xeb0 security/tomoyo/common.c:2097
tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
tomoyo_path_number_perm+0x3ed/0x4d0 security/tomoyo/file.c:734
security_file_ioctl+0x50/0xb0 security/security.c:1489
ksys_ioctl+0x50/0x180 fs/ioctl.c:747
__do_sys_ioctl fs/ioctl.c:762 [inline]
__se_sys_ioctl fs/ioctl.c:760 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 6811:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
__kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
__cache_free mm/slab.c:3418 [inline]
kfree+0x103/0x2c0 mm/slab.c:3756
tomoyo_supervisor+0x350/0xeb0 security/tomoyo/common.c:2149
tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
tomoyo_path_number_perm+0x3ed/0x4d0 security/tomoyo/file.c:734
security_file_ioctl+0x50/0xb0 security/security.c:1489
ksys_ioctl+0x50/0x180 fs/ioctl.c:747
__do_sys_ioctl fs/ioctl.c:762 [inline]
__se_sys_ioctl fs/ioctl.c:760 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff888093457800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 168 bytes inside of
512-byte region [ffff888093457800, ffff888093457a00)
The buggy address belongs to the page:
page:000000005c2b5911 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x93457
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00028d4308 ffffea0002834c88 ffff8880aa000600
raw: 0000000000000000 ffff888093457000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888093457780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888093457800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888093457880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888093457900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888093457980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Reported-and-tested-by: syzbot+72ff2fa98097767b5a27@syzkaller.appspotmail.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: B K Karthik <bkkarthik@pesu.pes.edu>
---

v1 -> v2:
added cast in arguement from u32 to (const xfrm_address_t *)
added Reported-by: kernel test robot <lkp@intel.com>
removed Reported-by: syzbot+72ff2fa98097767b5a27@syzkaller.appspotmail.com
added Reported-and-tested-by: syzbot+72ff2fa98097767b5a27@syzkaller.appspotmail.com

net/ipv6/xfrm6_tunnel.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/xfrm6_tunnel.c b/net/ipv6/xfrm6_tunnel.c
index 25b7ebda2fab..a0e18be2145f 100644
--- a/net/ipv6/xfrm6_tunnel.c
+++ b/net/ipv6/xfrm6_tunnel.c
@@ -103,10 +103,10 @@ static int __xfrm6_tunnel_spi_check(struct net *net, u32 spi)
{
struct xfrm6_tunnel_net *xfrm6_tn = xfrm6_tunnel_pernet(net);
struct xfrm6_tunnel_spi *x6spi;
- int index = xfrm6_tunnel_spi_hash_byspi(spi);
+ int index = xfrm6_tunnel_spi_hash_byaddr((const xfrm_address_t *)spi);

hlist_for_each_entry(x6spi,
- &xfrm6_tn->spi_byspi[index],
+ &xfrm6_tn->spi_byaddr[index],
list_byspi) {
if (x6spi->spi == spi)
return -1;
--
2.20.1
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2020-07-26 05:09    [W:0.399 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site