From: J. Bruce Fields Date: Sat, 1 May 2010 16:56:06 +0000 (-0400) Subject: nfsd4: fix bare destroy_session null dereference X-Git-Tag: cont_sys_log_2~3^2~16 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=5d4cec2f2fdbb3d830fa014226d0d965df548bad nfsd4: fix bare destroy_session null dereference It's legal to send a DESTROY_SESSION outside any session (as the only operation in a compound), in which case cstate->session will be NULL; check for that case. While we're at it, move these checks into a separate helper function. Signed-off-by: J. Bruce Fields --- diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index f05a327..835d6ce 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -1352,6 +1352,13 @@ static bool nfsd4_last_compound_op(struct svc_rqst *rqstp) return argp->opcnt == resp->opcnt; } +static bool nfsd4_compound_in_session(struct nfsd4_session *session, struct nfs4_sessionid *sid) +{ + if (!session) + return 0; + return !memcmp(sid, &session->se_sessionid, sizeof(*sid)); +} + __be32 nfsd4_destroy_session(struct svc_rqst *r, struct nfsd4_compound_state *cstate, @@ -1367,8 +1374,7 @@ nfsd4_destroy_session(struct svc_rqst *r, * - Do we need to clear any callback info from previous session? */ - if (!memcmp(&sessionid->sessionid, &cstate->session->se_sessionid, - sizeof(struct nfs4_sessionid))) { + if (nfsd4_compound_in_session(cstate->session, &sessionid->sessionid)) { if (!nfsd4_last_compound_op(r)) return nfserr_not_only_op; }