mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 12:28:41 +08:00
ceph: fix potential use-after-free bug when trimming caps
When trimming the caps and just after the 'session->s_cap_lock' is released in ceph_iterate_session_caps() the cap maybe removed by another thread, and when using the stale cap memory in the callbacks it will trigger use-after-free crash. We need to check the existence of the cap just after the 'ci->i_ceph_lock' being acquired. And do nothing if it's already removed. Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/43272 Signed-off-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Luís Henriques <lhenriques@suse.de> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Xiubo Li
Ilya Dryomov
parent
7d41870d65
commit
aaf67de788
@ -431,7 +431,7 @@ void ceph_reservation_status(struct ceph_fs_client *fsc,
|
||||
*
|
||||
* Called with i_ceph_lock held.
|
||||
*/
|
||||
static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
|
||||
struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
|
||||
{
|
||||
struct ceph_cap *cap;
|
||||
struct rb_node *n = ci->i_caps.rb_node;
|
||||
|
||||
@ -248,14 +248,20 @@ static int metrics_caps_show(struct seq_file *s, void *p)
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int caps_show_cb(struct inode *inode, struct ceph_cap *cap, void *p)
|
||||
static int caps_show_cb(struct inode *inode, int mds, void *p)
|
||||
{
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
struct seq_file *s = p;
|
||||
struct ceph_cap *cap;
|
||||
|
||||
seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode),
|
||||
cap->session->s_mds,
|
||||
ceph_cap_string(cap->issued),
|
||||
ceph_cap_string(cap->implemented));
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
cap = __get_cap_for_mds(ci, mds);
|
||||
if (cap)
|
||||
seq_printf(s, "0x%-17llx%-3d%-17s%-17s\n", ceph_ino(inode),
|
||||
cap->session->s_mds,
|
||||
ceph_cap_string(cap->issued),
|
||||
ceph_cap_string(cap->implemented));
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
@ -1632,8 +1632,8 @@ static void cleanup_session_requests(struct ceph_mds_client *mdsc,
|
||||
* Caller must hold session s_mutex.
|
||||
*/
|
||||
int ceph_iterate_session_caps(struct ceph_mds_session *session,
|
||||
int (*cb)(struct inode *, struct ceph_cap *,
|
||||
void *), void *arg)
|
||||
int (*cb)(struct inode *, int mds, void *),
|
||||
void *arg)
|
||||
{
|
||||
struct list_head *p;
|
||||
struct ceph_cap *cap;
|
||||
@ -1645,6 +1645,8 @@ int ceph_iterate_session_caps(struct ceph_mds_session *session,
|
||||
spin_lock(&session->s_cap_lock);
|
||||
p = session->s_caps.next;
|
||||
while (p != &session->s_caps) {
|
||||
int mds;
|
||||
|
||||
cap = list_entry(p, struct ceph_cap, session_caps);
|
||||
inode = igrab(&cap->ci->netfs.inode);
|
||||
if (!inode) {
|
||||
@ -1652,6 +1654,7 @@ int ceph_iterate_session_caps(struct ceph_mds_session *session,
|
||||
continue;
|
||||
}
|
||||
session->s_cap_iterator = cap;
|
||||
mds = cap->mds;
|
||||
spin_unlock(&session->s_cap_lock);
|
||||
|
||||
if (last_inode) {
|
||||
@ -1663,7 +1666,7 @@ int ceph_iterate_session_caps(struct ceph_mds_session *session,
|
||||
old_cap = NULL;
|
||||
}
|
||||
|
||||
ret = cb(inode, cap, arg);
|
||||
ret = cb(inode, mds, arg);
|
||||
last_inode = inode;
|
||||
|
||||
spin_lock(&session->s_cap_lock);
|
||||
@ -1696,20 +1699,25 @@ out:
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
|
||||
void *arg)
|
||||
static int remove_session_caps_cb(struct inode *inode, int mds, void *arg)
|
||||
{
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
bool invalidate = false;
|
||||
int iputs;
|
||||
struct ceph_cap *cap;
|
||||
int iputs = 0;
|
||||
|
||||
dout("removing cap %p, ci is %p, inode is %p\n",
|
||||
cap, ci, &ci->netfs.inode);
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
iputs = ceph_purge_inode_cap(inode, cap, &invalidate);
|
||||
cap = __get_cap_for_mds(ci, mds);
|
||||
if (cap) {
|
||||
dout(" removing cap %p, ci is %p, inode is %p\n",
|
||||
cap, ci, &ci->netfs.inode);
|
||||
|
||||
iputs = ceph_purge_inode_cap(inode, cap, &invalidate);
|
||||
}
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
|
||||
wake_up_all(&ci->i_cap_wq);
|
||||
if (cap)
|
||||
wake_up_all(&ci->i_cap_wq);
|
||||
if (invalidate)
|
||||
ceph_queue_invalidate(inode);
|
||||
while (iputs--)
|
||||
@ -1780,8 +1788,7 @@ enum {
|
||||
*
|
||||
* caller must hold s_mutex.
|
||||
*/
|
||||
static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
|
||||
void *arg)
|
||||
static int wake_up_session_cb(struct inode *inode, int mds, void *arg)
|
||||
{
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
unsigned long ev = (unsigned long)arg;
|
||||
@ -1792,12 +1799,14 @@ static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
|
||||
ci->i_requested_max_size = 0;
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
} else if (ev == RENEWCAPS) {
|
||||
if (cap->cap_gen < atomic_read(&cap->session->s_cap_gen)) {
|
||||
/* mds did not re-issue stale cap */
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
struct ceph_cap *cap;
|
||||
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
cap = __get_cap_for_mds(ci, mds);
|
||||
/* mds did not re-issue stale cap */
|
||||
if (cap && cap->cap_gen < atomic_read(&cap->session->s_cap_gen))
|
||||
cap->issued = cap->implemented = CEPH_CAP_PIN;
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
}
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
} else if (ev == FORCE_RO) {
|
||||
}
|
||||
wake_up_all(&ci->i_cap_wq);
|
||||
@ -1959,16 +1968,22 @@ out:
|
||||
* Yes, this is a bit sloppy. Our only real goal here is to respond to
|
||||
* memory pressure from the MDS, though, so it needn't be perfect.
|
||||
*/
|
||||
static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
|
||||
static int trim_caps_cb(struct inode *inode, int mds, void *arg)
|
||||
{
|
||||
int *remaining = arg;
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
int used, wanted, oissued, mine;
|
||||
struct ceph_cap *cap;
|
||||
|
||||
if (*remaining <= 0)
|
||||
return -1;
|
||||
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
cap = __get_cap_for_mds(ci, mds);
|
||||
if (!cap) {
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
return 0;
|
||||
}
|
||||
mine = cap->issued | cap->implemented;
|
||||
used = __ceph_caps_used(ci);
|
||||
wanted = __ceph_caps_file_wanted(ci);
|
||||
@ -3911,26 +3926,22 @@ out_unlock:
|
||||
/*
|
||||
* Encode information about a cap for a reconnect with the MDS.
|
||||
*/
|
||||
static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
|
||||
void *arg)
|
||||
static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
|
||||
{
|
||||
union {
|
||||
struct ceph_mds_cap_reconnect v2;
|
||||
struct ceph_mds_cap_reconnect_v1 v1;
|
||||
} rec;
|
||||
struct ceph_inode_info *ci = cap->ci;
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
struct ceph_reconnect_state *recon_state = arg;
|
||||
struct ceph_pagelist *pagelist = recon_state->pagelist;
|
||||
struct dentry *dentry;
|
||||
struct ceph_cap *cap;
|
||||
char *path;
|
||||
int pathlen = 0, err;
|
||||
int pathlen = 0, err = 0;
|
||||
u64 pathbase;
|
||||
u64 snap_follows;
|
||||
|
||||
dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
|
||||
inode, ceph_vinop(inode), cap, cap->cap_id,
|
||||
ceph_cap_string(cap->issued));
|
||||
|
||||
dentry = d_find_primary(inode);
|
||||
if (dentry) {
|
||||
/* set pathbase to parent dir when msg_version >= 2 */
|
||||
@ -3947,6 +3958,15 @@ static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
|
||||
}
|
||||
|
||||
spin_lock(&ci->i_ceph_lock);
|
||||
cap = __get_cap_for_mds(ci, mds);
|
||||
if (!cap) {
|
||||
spin_unlock(&ci->i_ceph_lock);
|
||||
goto out_err;
|
||||
}
|
||||
dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
|
||||
inode, ceph_vinop(inode), cap, cap->cap_id,
|
||||
ceph_cap_string(cap->issued));
|
||||
|
||||
cap->seq = 0; /* reset cap seq */
|
||||
cap->issue_seq = 0; /* and issue_seq */
|
||||
cap->mseq = 0; /* and migrate_seq */
|
||||
|
||||
@ -541,8 +541,7 @@ extern void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
|
||||
extern void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc);
|
||||
extern void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr);
|
||||
extern int ceph_iterate_session_caps(struct ceph_mds_session *session,
|
||||
int (*cb)(struct inode *,
|
||||
struct ceph_cap *, void *),
|
||||
int (*cb)(struct inode *, int mds, void *),
|
||||
void *arg);
|
||||
extern void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc);
|
||||
|
||||
|
||||
@ -1192,6 +1192,8 @@ extern void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
|
||||
struct ceph_mds_session *session);
|
||||
void ceph_kick_flushing_inode_caps(struct ceph_mds_session *session,
|
||||
struct ceph_inode_info *ci);
|
||||
extern struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci,
|
||||
int mds);
|
||||
extern struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci,
|
||||
int mds);
|
||||
extern void ceph_take_cap_refs(struct ceph_inode_info *ci, int caps,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user