summaryrefslogtreecommitdiffstats
path: root/fs/cachefiles
diff options
context:
space:
mode:
Diffstat (limited to 'fs/cachefiles')
-rw-r--r--fs/cachefiles/daemon.c4
-rw-r--r--fs/cachefiles/internal.h3
-rw-r--r--fs/cachefiles/ondemand.c52
-rw-r--r--fs/cachefiles/xattr.c5
4 files changed, 55 insertions, 9 deletions
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 06cdf1a8a1..89b11336a8 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -366,14 +366,14 @@ static __poll_t cachefiles_daemon_poll(struct file *file,
if (cachefiles_in_ondemand_mode(cache)) {
if (!xa_empty(&cache->reqs)) {
- rcu_read_lock();
+ xas_lock(&xas);
xas_for_each_marked(&xas, req, ULONG_MAX, CACHEFILES_REQ_NEW) {
if (!cachefiles_ondemand_is_reopening_read(req)) {
mask |= EPOLLIN;
break;
}
}
- rcu_read_unlock();
+ xas_unlock(&xas);
}
} else {
if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags))
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 6845a90cdf..7b99bd98de 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -48,6 +48,7 @@ enum cachefiles_object_state {
CACHEFILES_ONDEMAND_OBJSTATE_CLOSE, /* Anonymous fd closed by daemon or initial state */
CACHEFILES_ONDEMAND_OBJSTATE_OPEN, /* Anonymous fd associated with object is available */
CACHEFILES_ONDEMAND_OBJSTATE_REOPENING, /* Object that was closed and is being reopened. */
+ CACHEFILES_ONDEMAND_OBJSTATE_DROPPING, /* Object is being dropped. */
};
struct cachefiles_ondemand_info {
@@ -128,6 +129,7 @@ struct cachefiles_cache {
unsigned long req_id_next;
struct xarray ondemand_ids; /* xarray for ondemand_id allocation */
u32 ondemand_id_next;
+ u32 msg_id_next;
};
static inline bool cachefiles_in_ondemand_mode(struct cachefiles_cache *cache)
@@ -335,6 +337,7 @@ cachefiles_ondemand_set_object_##_state(struct cachefiles_object *object) \
CACHEFILES_OBJECT_STATE_FUNCS(open, OPEN);
CACHEFILES_OBJECT_STATE_FUNCS(close, CLOSE);
CACHEFILES_OBJECT_STATE_FUNCS(reopening, REOPENING);
+CACHEFILES_OBJECT_STATE_FUNCS(dropping, DROPPING);
static inline bool cachefiles_ondemand_is_reopening_read(struct cachefiles_req *req)
{
diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c
index 89f118d68d..7e4874f60d 100644
--- a/fs/cachefiles/ondemand.c
+++ b/fs/cachefiles/ondemand.c
@@ -494,7 +494,8 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
*/
xas_lock(&xas);
- if (test_bit(CACHEFILES_DEAD, &cache->flags)) {
+ if (test_bit(CACHEFILES_DEAD, &cache->flags) ||
+ cachefiles_ondemand_object_is_dropping(object)) {
xas_unlock(&xas);
ret = -EIO;
goto out;
@@ -504,20 +505,32 @@ static int cachefiles_ondemand_send_req(struct cachefiles_object *object,
smp_mb();
if (opcode == CACHEFILES_OP_CLOSE &&
- !cachefiles_ondemand_object_is_open(object)) {
+ !cachefiles_ondemand_object_is_open(object)) {
WARN_ON_ONCE(object->ondemand->ondemand_id == 0);
xas_unlock(&xas);
ret = -EIO;
goto out;
}
- xas.xa_index = 0;
+ /*
+ * Cyclically find a free xas to avoid msg_id reuse that would
+ * cause the daemon to successfully copen a stale msg_id.
+ */
+ xas.xa_index = cache->msg_id_next;
xas_find_marked(&xas, UINT_MAX, XA_FREE_MARK);
+ if (xas.xa_node == XAS_RESTART) {
+ xas.xa_index = 0;
+ xas_find_marked(&xas, cache->msg_id_next - 1, XA_FREE_MARK);
+ }
if (xas.xa_node == XAS_RESTART)
xas_set_err(&xas, -EBUSY);
+
xas_store(&xas, req);
- xas_clear_mark(&xas, XA_FREE_MARK);
- xas_set_mark(&xas, CACHEFILES_REQ_NEW);
+ if (xas_valid(&xas)) {
+ cache->msg_id_next = xas.xa_index + 1;
+ xas_clear_mark(&xas, XA_FREE_MARK);
+ xas_set_mark(&xas, CACHEFILES_REQ_NEW);
+ }
xas_unlock(&xas);
} while (xas_nomem(&xas, GFP_KERNEL));
@@ -535,7 +548,8 @@ out:
* If error occurs after creating the anonymous fd,
* cachefiles_ondemand_fd_release() will set object to close.
*/
- if (opcode == CACHEFILES_OP_OPEN)
+ if (opcode == CACHEFILES_OP_OPEN &&
+ !cachefiles_ondemand_object_is_dropping(object))
cachefiles_ondemand_set_object_close(object);
kfree(req);
return ret;
@@ -634,8 +648,34 @@ int cachefiles_ondemand_init_object(struct cachefiles_object *object)
void cachefiles_ondemand_clean_object(struct cachefiles_object *object)
{
+ unsigned long index;
+ struct cachefiles_req *req;
+ struct cachefiles_cache *cache;
+
+ if (!object->ondemand)
+ return;
+
cachefiles_ondemand_send_req(object, CACHEFILES_OP_CLOSE, 0,
cachefiles_ondemand_init_close_req, NULL);
+
+ if (!object->ondemand->ondemand_id)
+ return;
+
+ /* Cancel all requests for the object that is being dropped. */
+ cache = object->volume->cache;
+ xa_lock(&cache->reqs);
+ cachefiles_ondemand_set_object_dropping(object);
+ xa_for_each(&cache->reqs, index, req) {
+ if (req->object == object) {
+ req->error = -EIO;
+ complete(&req->done);
+ __xa_erase(&cache->reqs, index);
+ }
+ }
+ xa_unlock(&cache->reqs);
+
+ /* Wait for ondemand_object_worker() to finish to avoid UAF. */
+ cancel_work_sync(&object->ondemand->ondemand_work);
}
int cachefiles_ondemand_init_obj_info(struct cachefiles_object *object,
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index bcb6173943..4dd8a993c6 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -110,9 +110,11 @@ int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file
if (xlen == 0)
xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, tlen);
if (xlen != tlen) {
- if (xlen < 0)
+ if (xlen < 0) {
+ ret = xlen;
trace_cachefiles_vfs_error(object, file_inode(file), xlen,
cachefiles_trace_getxattr_error);
+ }
if (xlen == -EIO)
cachefiles_io_error_obj(
object,
@@ -252,6 +254,7 @@ int cachefiles_check_volume_xattr(struct cachefiles_volume *volume)
xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, len);
if (xlen != len) {
if (xlen < 0) {
+ ret = xlen;
trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen,
cachefiles_trace_getxattr_error);
if (xlen == -EIO)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 22:42:41 +0000