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| author |   Dust Li <dust.li@linux.alibaba.com> | 2019-04-01 16:04:53 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-04-01 10:11:41 -0700 |
| commit | b506bc975f60f06e13e74adb35e708a23dc4e87c (patch) | |
| tree | 90a10d72c1a9e02ce8e5de0d7f23ae114b8f6ea7 /net/ipv4 | |
| parent | Merge branch 'tipc-a-batch-of-uninit-value-fixes-for-netlink_compat' (diff) | |
| download | linux-dev-b506bc975f60f06e13e74adb35e708a23dc4e87c.tar.xz linux-dev-b506bc975f60f06e13e74adb35e708a23dc4e87c.zip | |
tcp: fix a potential NULL pointer dereference in tcp_sk_exit
When tcp_sk_init() failed in inet_ctl_sock_create(),
'net->ipv4.tcp_congestion_control' will be left
uninitialized, but tcp_sk_exit() hasn't check for
that.
This patch add checking on 'net->ipv4.tcp_congestion_control'
in tcp_sk_exit() to prevent NULL-ptr dereference.
Fixes: 6670e1524477 ("tcp: Namespace-ify sysctl_tcp_default_congestion_control")
Signed-off-by: Dust Li <dust.li@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 277d71239d75..2f8039a26b08 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2578,7 +2578,8 @@ static void __net_exit tcp_sk_exit(struct net *net) { int cpu; - module_put(net->ipv4.tcp_congestion_control->owner); + if (net->ipv4.tcp_congestion_control) + module_put(net->ipv4.tcp_congestion_control->owner); for_each_possible_cpu(cpu) inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu)); |