diff options
author | Dmitry Torokhov <dtor@chromium.org> | 2015-09-03 14:48:52 -0700 |
---|---|---|
committer | John Stultz <john.stultz@linaro.org> | 2015-11-19 12:36:40 -0800 |
commit | 703653d46f08be3e0d90915cad80f19129cf9416 (patch) | |
tree | 4c554ad2cde000e25e03f97bb41261bc8c1d58b7 /net | |
parent | 07b9a3a22ac7db34f2399a7cabc7e4ba71b7089b (diff) | |
download | v4.1-703653d46f08be3e0d90915cad80f19129cf9416.tar.gz |
net: xt_qtaguid/xt_socket: fix refcount underflow and crash
xt_socket_get[4|6]_sk() do not always increment sock refcount, which
causes confusion in xt_qtaguid module which is not aware of this fact
and drops the reference whether it should have or not. Fix it by
changing xt_socket_get[4|6]_sk() to always increment recount of returned
sock.
This should fix the following crash:
[ 111.319523] BUG: failure at
/mnt/host/source/src/third_party/kernel/v3.18/net/ipv4/inet_timewait_sock.c:90/__inet_twsk_kill()!
[ 111.331192] Kernel panic - not syncing: BUG!
[ 111.335468] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G U W
3.18.0-06867-g268df91 #1
[ 111.343810] Hardware name: Google Tegra210 Smaug Rev 1+ (DT)
[ 111.349463] Call trace:
[ 111.351917] [<ffffffc000207288>] dump_backtrace+0x0/0x10c
[ 111.357314] [<ffffffc0002073a4>] show_stack+0x10/0x1c
[ 111.362367] [<ffffffc000a82d1c>] dump_stack+0x74/0x94
[ 111.367414] [<ffffffc000a81824>] panic+0xec/0x238
[ 111.372116] [<ffffffc000981648>] __inet_twsk_kill+0xd0/0xf8
[ 111.377684] [<ffffffc0009817b0>] inet_twdr_do_twkill_work+0x64/0xd0
[ 111.383946] [<ffffffc000981a5c>] inet_twdr_hangman+0x2c/0xa4
[ 111.389602] [<ffffffc000271cf0>] call_timer_fn+0xac/0x160
[ 111.394995] [<ffffffc00027250c>] run_timer_softirq+0x23c/0x274
[ 111.400824] [<ffffffc000220a68>] __do_softirq+0x1a4/0x330
[ 111.406218] [<ffffffc000220e94>] irq_exit+0x70/0xd0
[ 111.411093] [<ffffffc000264e00>] __handle_domain_irq+0x84/0xa8
[ 111.416922] [<ffffffc0002003ec>] gic_handle_irq+0x4c/0x80
b/22476945
Originally reviewed at:
https://chromium-review.googlesource.com/#/c/297414/
Change-Id: I51fa94a9d92a84a0bd3b58466d711e46a6892a79
Signed-off-by: Dmitry Torokhov <dtor@google.com>
[jstultz: Cherry-picked and added missing local var definition]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'net')
-rw-r--r-- | net/netfilter/xt_socket.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c index ae1a2c6d553..281f4d65b6e 100644 --- a/net/netfilter/xt_socket.c +++ b/net/netfilter/xt_socket.c @@ -147,6 +147,7 @@ struct sock *xt_socket_lookup_slow_v4(const struct sk_buff *skb, const struct net_device *indev) { const struct iphdr *iph = ip_hdr(skb); + struct sock *sk = skb->sk; __be32 uninitialized_var(daddr), uninitialized_var(saddr); __be16 uninitialized_var(dport), uninitialized_var(sport); u8 uninitialized_var(protocol); @@ -197,8 +198,14 @@ struct sock *xt_socket_lookup_slow_v4(const struct sk_buff *skb, } #endif - return xt_socket_get_sock_v4(dev_net(skb->dev), protocol, saddr, daddr, - sport, dport, indev); + if (sk) + atomic_inc(&sk->sk_refcnt); + else + sk = xt_socket_get_sock_v4(dev_net(skb->dev), protocol, + saddr, daddr, sport, dport, + indev); + + return sk; } EXPORT_SYMBOL(xt_socket_lookup_slow_v4); @@ -227,8 +234,7 @@ socket_match(const struct sk_buff *skb, struct xt_action_param *par, if (info->flags & XT_SOCKET_TRANSPARENT) transparent = xt_socket_sk_is_transparent(sk); - if (sk != skb->sk) - sock_gen_put(sk); + sock_gen_put(sk); if (wildcard || !transparent) sk = NULL; @@ -334,6 +340,7 @@ xt_socket_get_sock_v6(struct net *net, const u8 protocol, struct sock *xt_socket_lookup_slow_v6(const struct sk_buff *skb, const struct net_device *indev) { + struct sock *sk = skb->sk; __be16 uninitialized_var(dport), uninitialized_var(sport); const struct in6_addr *daddr = NULL, *saddr = NULL; struct ipv6hdr *iph = ipv6_hdr(skb); @@ -367,8 +374,14 @@ struct sock *xt_socket_lookup_slow_v6(const struct sk_buff *skb, return NULL; } - return xt_socket_get_sock_v6(dev_net(skb->dev), tproto, saddr, daddr, - sport, dport, indev); + if (sk) + atomic_inc(&sk->sk_refcnt); + else + sk = xt_socket_get_sock_v6(dev_net(skb->dev), tproto, + saddr, daddr, sport, dport, + indev); + + return sk; } EXPORT_SYMBOL(xt_socket_lookup_slow_v6); |