From 32852a81bccd9e3d1953b894966393d1b546576d Mon Sep 17 00:00:00 2001 From: Xi Wang Date: Sat, 14 Jan 2012 22:20:59 -0500 Subject: ceph: fix length validation in parse_reply_info() "len" is read from network and thus needs validation. Otherwise, given a bogus "len" value, p+len could be an out-of-bounds pointer, which is used in further parsing. Signed-off-by: Xi Wang Signed-off-by: Sage Weil --- fs/ceph/mds_client.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/ceph/mds_client.c') diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 6203d805eb45..be1415fcaac8 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -262,6 +262,7 @@ static int parse_reply_info(struct ceph_msg *msg, /* trace */ ceph_decode_32_safe(&p, end, len, bad); if (len > 0) { + ceph_decode_need(&p, end, len, bad); err = parse_reply_info_trace(&p, p+len, info, features); if (err < 0) goto out_bad; @@ -270,6 +271,7 @@ static int parse_reply_info(struct ceph_msg *msg, /* extra */ ceph_decode_32_safe(&p, end, len, bad); if (len > 0) { + ceph_decode_need(&p, end, len, bad); err = parse_reply_info_extra(&p, p+len, info, features); if (err < 0) goto out_bad; -- cgit v1.2.3 From d8fb02abdc39f92a1066313e2b17047876afa8f9 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 12 Jan 2012 17:48:10 -0800 Subject: ceph: create a new session lock to avoid lock inversion Lockdep was reporting a possible circular lock dependency in dentry_lease_is_valid(). That function needs to sample the session's s_cap_gen and and s_cap_ttl fields coherently, but needs to do so while holding a dentry lock. The s_cap_lock field was being used to protect the two fields, but that can't be taken while holding a lock on a dentry within the session. In most cases, the s_cap_gen and s_cap_ttl fields only get operated on separately. But in three cases they need to be updated together. Implement a new lock to protect the spots updating both fields atomically is required. Signed-off-by: Alex Elder Reviewed-by: Sage Weil --- fs/ceph/mds_client.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs/ceph/mds_client.c') diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index be1415fcaac8..a4fdf9397a90 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -400,9 +400,11 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc, s->s_con.peer_name.type = CEPH_ENTITY_TYPE_MDS; s->s_con.peer_name.num = cpu_to_le64(mds); - spin_lock_init(&s->s_cap_lock); + spin_lock_init(&s->s_gen_ttl_lock); s->s_cap_gen = 0; s->s_cap_ttl = 0; + + spin_lock_init(&s->s_cap_lock); s->s_renew_requested = 0; s->s_renew_seq = 0; INIT_LIST_HEAD(&s->s_caps); @@ -2328,10 +2330,10 @@ static void handle_session(struct ceph_mds_session *session, case CEPH_SESSION_STALE: pr_info("mds%d caps went stale, renewing\n", session->s_mds); - spin_lock(&session->s_cap_lock); + spin_lock(&session->s_gen_ttl_lock); session->s_cap_gen++; session->s_cap_ttl = 0; - spin_unlock(&session->s_cap_lock); + spin_unlock(&session->s_gen_ttl_lock); send_renew_caps(mdsc, session); break; -- cgit v1.2.3