diff options
| author | NeilBrown <neilb@suse.de> | 2007-04-17 12:01:41 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-05-01 17:05:53 -0700 |
| commit | bd8622520f56b6a0d453ab895ca3272328bf66d0 (patch) | |
| tree | 7552a53b360d685b272e08070013c9607441a486 /net | |
| parent | d2bc7047d6c512fb412acd5a2c150d266e5080cd (diff) | |
knfsd: Use a spinlock to protect sk_info_authunix
sk_info_authunix is not being protected properly so the object that
it points to can be cache_put twice, leading to corruption.
We borrow svsk->sk_defer_lock to provide the protection. We should probably
rename that lock to have a more generic name - later.
Thanks to Gabriel for reporting this.
Cc: Greg Banks <gnb@melbourne.sgi.com>
Cc: Gabriel Barazer <gabriel@oxeva.fr>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/svcauth_unix.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c index 0d1e8fb83b9..a568f9f541b 100644 --- a/net/sunrpc/svcauth_unix.c +++ b/net/sunrpc/svcauth_unix.c @@ -383,7 +383,10 @@ void svcauth_unix_purge(void) static inline struct ip_map * ip_map_cached_get(struct svc_rqst *rqstp) { - struct ip_map *ipm = rqstp->rq_sock->sk_info_authunix; + struct ip_map *ipm; + struct svc_sock *svsk = rqstp->rq_sock; + spin_lock_bh(&svsk->sk_defer_lock); + ipm = svsk->sk_info_authunix; if (ipm != NULL) { if (!cache_valid(&ipm->h)) { /* @@ -391,12 +394,14 @@ ip_map_cached_get(struct svc_rqst *rqstp) * remembered, e.g. by a second mount from the * same IP address. */ - rqstp->rq_sock->sk_info_authunix = NULL; + svsk->sk_info_authunix = NULL; + spin_unlock_bh(&svsk->sk_defer_lock); cache_put(&ipm->h, &ip_map_cache); return NULL; } cache_get(&ipm->h); } + spin_unlock_bh(&svsk->sk_defer_lock); return ipm; } @@ -405,9 +410,15 @@ ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm) { struct svc_sock *svsk = rqstp->rq_sock; - if (svsk->sk_sock->type == SOCK_STREAM && svsk->sk_info_authunix == NULL) - svsk->sk_info_authunix = ipm; /* newly cached, keep the reference */ - else + spin_lock_bh(&svsk->sk_defer_lock); + if (svsk->sk_sock->type == SOCK_STREAM && + svsk->sk_info_authunix == NULL) { + /* newly cached, keep the reference */ + svsk->sk_info_authunix = ipm; + ipm = NULL; + } + spin_unlock_bh(&svsk->sk_defer_lock); + if (ipm) cache_put(&ipm->h, &ip_map_cache); } |