netfilter: nfnetlink: Fix use after free when it fails to process batch
authorDenys Fedoryshchenko <nuclearcat@nuclearcat.com>
Sun, 4 May 2014 11:35:37 +0000 (13:35 +0200)
committerPablo Neira Ayuso <pablo@netfilter.org>
Sun, 4 May 2014 13:14:08 +0000 (15:14 +0200)
commitecd15dd7e45f3683fa8142b9f2c015dfaa0c243d
tree15ad404326397ee91b5290f9ce8156c25662c645
parent895162b1101b3ea5db08ca6822ae9672717efec0
netfilter: nfnetlink: Fix use after free when it fails to process batch

This bug manifests when calling the nft command line tool without
nf_tables kernel support.

kernel message:
[   44.071555] Netfilter messages via NETLINK v0.30.
[   44.072253] BUG: unable to handle kernel NULL pointer dereference at 0000000000000119
[   44.072264] IP: [<ffffffff8171db1f>] netlink_getsockbyportid+0xf/0x70
[   44.072272] PGD 7f2b74067 PUD 7f2b73067 PMD 0
[   44.072277] Oops: 0000 [#1] SMP
[...]
[   44.072369] Call Trace:
[   44.072373]  [<ffffffff8171fd81>] netlink_unicast+0x91/0x200
[   44.072377]  [<ffffffff817206c9>] netlink_ack+0x99/0x110
[   44.072381]  [<ffffffffa004b951>] nfnetlink_rcv+0x3c1/0x408 [nfnetlink]
[   44.072385]  [<ffffffff8171fde3>] netlink_unicast+0xf3/0x200
[   44.072389]  [<ffffffff817201ef>] netlink_sendmsg+0x2ff/0x740
[   44.072394]  [<ffffffff81044752>] ? __mmdrop+0x62/0x90
[   44.072398]  [<ffffffff816dafdb>] sock_sendmsg+0x8b/0xc0
[   44.072403]  [<ffffffff812f1af5>] ? copy_user_enhanced_fast_string+0x5/0x10
[   44.072406]  [<ffffffff816dbb6c>] ? move_addr_to_kernel+0x2c/0x50
[   44.072410]  [<ffffffff816db423>] ___sys_sendmsg+0x3c3/0x3d0
[   44.072415]  [<ffffffff811301ba>] ? handle_mm_fault+0xa9a/0xc60
[   44.072420]  [<ffffffff811362d6>] ? mmap_region+0x166/0x5a0
[   44.072424]  [<ffffffff817da84c>] ? __do_page_fault+0x1dc/0x510
[   44.072428]  [<ffffffff812b8b2c>] ? apparmor_capable+0x1c/0x60
[   44.072435]  [<ffffffff817d6e9a>] ? _raw_spin_unlock_bh+0x1a/0x20
[   44.072439]  [<ffffffff816dfc86>] ? release_sock+0x106/0x150
[   44.072443]  [<ffffffff816dc212>] __sys_sendmsg+0x42/0x80
[   44.072446]  [<ffffffff816dc262>] SyS_sendmsg+0x12/0x20
[   44.072450]  [<ffffffff817df616>] system_call_fastpath+0x1a/0x1f

Signed-off-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net/netfilter/nfnetlink.c