From: Henry Ptasinski hptasinski@google.com
[ Upstream commit fe81d9f6182d1160e625894eecb3d7ff0222cac5 ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/net/sctp/structs.h | 8 +++++--- net/sctp/socket.c | 9 +++------ 2 files changed, 8 insertions(+), 9 deletions(-)
--- 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; }; --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -9457,13 +9457,10 @@ void sctp_copy_sock(struct sock *newsk, 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); }