From d198b27762644c71362e43a7533f89c92b115bcf Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 13 Sep 2021 22:18:51 -0700 Subject: Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"" This reverts commit d7807a9adf4856171f8441f13078c33941df48ab. As mentioned in https://lkml.org/lkml/2021/9/13/1819 5 years old commit 919483096bfe ("ipv4: fix memory leaks in ip_cmsg_send() callers") was a correct fix. ip_cmsg_send() can loop over multiple cmsghdr() If IP_RETOPTS has been successful, but following cmsghdr generates an error, we do not free ipc.ok If IP_RETOPTS is not successful, we have freed the allocated temporary space, not the one currently in ipc.opt. Sure, code could be refactored, but let's not bring back old bugs. Fixes: d7807a9adf48 ("Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"") Signed-off-by: Eric Dumazet Cc: Yajun Deng Signed-off-by: David S. Miller --- net/ipv4/ip_sockglue.c | 2 +- net/ipv4/ping.c | 5 +++-- net/ipv4/raw.c | 5 +++-- net/ipv4/udp.c | 5 +++-- 4 files changed, 10 insertions(+), 7 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 7cef9987ab4a..b297bb28556e 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -279,7 +279,7 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, case IP_RETOPTS: err = cmsg->cmsg_len - sizeof(struct cmsghdr); - /* Our caller is responsible for freeing ipc->opt when err = 0 */ + /* Our caller is responsible for freeing ipc->opt */ err = ip_options_get(net, &ipc->opt, KERNEL_SOCKPTR(CMSG_DATA(cmsg)), err < 40 ? err : 40); diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index c588f9f2f46c..1e44a43acfe2 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -727,9 +727,10 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (msg->msg_controllen) { err = ip_cmsg_send(sk, msg, &ipc, false); - if (unlikely(err)) + if (unlikely(err)) { + kfree(ipc.opt); return err; - + } if (ipc.opt) free = 1; } diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 1c98063a3ae8..bb446e60cf58 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -562,9 +562,10 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (msg->msg_controllen) { err = ip_cmsg_send(sk, msg, &ipc, false); - if (unlikely(err)) + if (unlikely(err)) { + kfree(ipc.opt); goto out; - + } if (ipc.opt) free = 1; } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index d5f5981d7a43..8851c9463b4b 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1122,9 +1122,10 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (err > 0) err = ip_cmsg_send(sk, msg, &ipc, sk->sk_family == AF_INET6); - if (unlikely(err < 0)) + if (unlikely(err < 0)) { + kfree(ipc.opt); return err; - + } if (ipc.opt) free = 1; connected = 0; -- cgit