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authorHenry Ptasinski <hptasinski@google.com>2020-09-19 03:12:11 +0300
committerDavid S. Miller <davem@davemloft.net>2020-09-21 00:15:12 +0300
commitfe81d9f6182d1160e625894eecb3d7ff0222cac5 (patch)
tree4ea97ca4097a651dc3e032b95363b44261f0375a
parentb6e11785cf957f4f4dd7da7f5a1f41ca4f1ea913 (diff)
downloadlinux-fe81d9f6182d1160e625894eecb3d7ff0222cac5.tar.xz
net: sctp: Fix IPv6 ancestor_size calc in sctp_copy_descendant
When calculating ancestor_size with IPv6 enabled, simply using sizeof(struct ipv6_pinfo) doesn't account for extra bytes needed for alignment in the struct sctp6_sock. On x86, there aren't any extra bytes, but on ARM the ipv6_pinfo structure is aligned on an 8-byte boundary so there were 4 pad bytes that were omitted from the ancestor_size calculation. This would lead to corruption of the pd_lobby pointers, causing an oops when trying to free the sctp structure on socket close. Fixes: 636d25d557d1 ("sctp: not copy sctp_sock pd_lobby in sctp_copy_descendant") Signed-off-by: Henry Ptasinski <hptasinski@google.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/sctp/structs.h8
-rw-r--r--net/sctp/socket.c9
2 files changed, 8 insertions, 9 deletions
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index b33f1aefad09..0bdff38eb4bb 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -226,12 +226,14 @@ struct sctp_sock {
data_ready_signalled:1;
atomic_t pd_mode;
+
+ /* Fields after this point will be skipped on copies, like on accept
+ * and peeloff operations
+ */
+
/* Receive to here while partial delivery is in effect. */
struct sk_buff_head pd_lobby;
- /* These must be the last fields, as they will skipped on copies,
- * like on accept and peeloff operations
- */
struct list_head auto_asconf_list;
int do_auto_asconf;
};
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 836615f71a7d..53d0a4161df3 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -9220,13 +9220,10 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
static inline void sctp_copy_descendant(struct sock *sk_to,
const struct sock *sk_from)
{
- int ancestor_size = sizeof(struct inet_sock) +
- sizeof(struct sctp_sock) -
- offsetof(struct sctp_sock, pd_lobby);
-
- if (sk_from->sk_family == PF_INET6)
- ancestor_size += sizeof(struct ipv6_pinfo);
+ size_t ancestor_size = sizeof(struct inet_sock);
+ ancestor_size += sk_from->sk_prot->obj_size;
+ ancestor_size -= offsetof(struct sctp_sock, pd_lobby);
__inet_sk_copy_descendant(sk_to, sk_from, ancestor_size);
}