From 293035479942400a7fe8e4f72465d4e4e466b91a Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Sun, 16 Sep 2007 16:02:12 -0700 Subject: [SCTP]: Add RCU synchronization around sctp_localaddr_list sctp_localaddr_list is modified dynamically via NETDEV_UP and NETDEV_DOWN events, but there is not synchronization between writer (even handler) and readers. As a result, the readers can access an entry that has been freed and crash the sytem. Signed-off-by: Vlad Yasevich Acked-by: Paul E. McKenney Acked-by: Sridhar Samdurala Signed-off-by: David S. Miller --- include/net/sctp/sctp.h | 1 + include/net/sctp/structs.h | 6 ++++++ 2 files changed, 7 insertions(+) (limited to 'include') diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index d529045c1679..c9cc00c85782 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -123,6 +123,7 @@ * sctp/protocol.c */ extern struct sock *sctp_get_ctl_sock(void); +extern void sctp_local_addr_free(struct rcu_head *head); extern int sctp_copy_local_addr_list(struct sctp_bind_addr *, sctp_scope_t, gfp_t gfp, int flags); diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index c0d5848c33dc..a89e36197afb 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -207,6 +207,9 @@ extern struct sctp_globals { * It is a list of sctp_sockaddr_entry. */ struct list_head local_addr_list; + + /* Lock that protects the local_addr_list writers */ + spinlock_t addr_list_lock; /* Flag to indicate if addip is enabled. */ int addip_enable; @@ -242,6 +245,7 @@ extern struct sctp_globals { #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) #define sctp_port_hashtable (sctp_globals.port_hashtable) #define sctp_local_addr_list (sctp_globals.local_addr_list) +#define sctp_local_addr_lock (sctp_globals.addr_list_lock) #define sctp_addip_enable (sctp_globals.addip_enable) #define sctp_prsctp_enable (sctp_globals.prsctp_enable) @@ -737,8 +741,10 @@ const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); /* This is a structure for holding either an IPv6 or an IPv4 address. */ struct sctp_sockaddr_entry { struct list_head list; + struct rcu_head rcu; union sctp_addr a; __u8 use_as_src; + __u8 valid; }; typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); -- cgit v1.2.3