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authorAmir Goldstein <amir73il@gmail.com>2021-11-29 22:15:35 +0200
committerJan Kara <jack@suse.cz>2021-12-15 15:55:53 +0100
commit2bfbcccde6e7a787feabad4645f628f963fe0663 (patch)
tree277e92c0ad85d9ed876a0167d3d0de9360b0aa2b /fs/notify
parent3982534ba5ce45e890b2f5ef5e7372c1accd14c7 (diff)
fanotify: record either old name new name or both for FAN_RENAME
We do not want to report the dirfid+name of a directory whose inode/sb are not watched, because watcher may not have permissions to see the directory content. Use an internal iter_info to indicate to fanotify_alloc_event() which marks of this group are watching FAN_RENAME, so it can decide if we need to record only the old parent+name, new parent+name or both. Link: https://lore.kernel.org/r/20211129201537.1932819-10-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> [JK: Modified code to pass around only mask of mark types matching generated event] Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/fanotify/fanotify.c59
1 files changed, 44 insertions, 15 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index db81eab90544..14bc0f12cc9f 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -284,8 +284,9 @@ out:
*/
static u32 fanotify_group_event_mask(struct fsnotify_group *group,
struct fsnotify_iter_info *iter_info,
- u32 event_mask, const void *data,
- int data_type, struct inode *dir)
+ u32 *match_mask, u32 event_mask,
+ const void *data, int data_type,
+ struct inode *dir)
{
__u32 marks_mask = 0, marks_ignored_mask = 0;
__u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS |
@@ -335,6 +336,9 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
continue;
marks_mask |= mark->mask;
+
+ /* Record the mark types of this group that matched the event */
+ *match_mask |= 1U << type;
}
test_mask = event_mask & marks_mask & ~marks_ignored_mask;
@@ -701,11 +705,11 @@ static struct fanotify_event *fanotify_alloc_error_event(
return &fee->fae;
}
-static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
- u32 mask, const void *data,
- int data_type, struct inode *dir,
- const struct qstr *file_name,
- __kernel_fsid_t *fsid)
+static struct fanotify_event *fanotify_alloc_event(
+ struct fsnotify_group *group,
+ u32 mask, const void *data, int data_type,
+ struct inode *dir, const struct qstr *file_name,
+ __kernel_fsid_t *fsid, u32 match_mask)
{
struct fanotify_event *event = NULL;
gfp_t gfp = GFP_KERNEL_ACCOUNT;
@@ -753,13 +757,36 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
}
/*
- * In the special case of FAN_RENAME event, we record both
- * old and new parent+name.
+ * In the special case of FAN_RENAME event, use the match_mask
+ * to determine if we need to report only the old parent+name,
+ * only the new parent+name or both.
* 'dirid' and 'file_name' are the old parent+name and
* 'moved' has the new parent+name.
*/
- if (mask & FAN_RENAME)
- moved = fsnotify_data_dentry(data, data_type);
+ if (mask & FAN_RENAME) {
+ bool report_old, report_new;
+
+ if (WARN_ON_ONCE(!match_mask))
+ return NULL;
+
+ /* Report both old and new parent+name if sb watching */
+ report_old = report_new =
+ match_mask & (1U << FSNOTIFY_ITER_TYPE_SB);
+ report_old |=
+ match_mask & (1U << FSNOTIFY_ITER_TYPE_INODE);
+ report_new |=
+ match_mask & (1U << FSNOTIFY_ITER_TYPE_INODE2);
+
+ if (!report_old) {
+ /* Do not report old parent+name */
+ dirid = NULL;
+ file_name = NULL;
+ }
+ if (report_new) {
+ /* Report new parent+name */
+ moved = fsnotify_data_dentry(data, data_type);
+ }
+ }
}
/*
@@ -872,6 +899,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
struct fanotify_event *event;
struct fsnotify_event *fsn_event;
__kernel_fsid_t fsid = {};
+ u32 match_mask = 0;
BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
@@ -897,12 +925,13 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 20);
- mask = fanotify_group_event_mask(group, iter_info, mask, data,
- data_type, dir);
+ mask = fanotify_group_event_mask(group, iter_info, &match_mask,
+ mask, data, data_type, dir);
if (!mask)
return 0;
- pr_debug("%s: group=%p mask=%x\n", __func__, group, mask);
+ pr_debug("%s: group=%p mask=%x report_mask=%x\n", __func__,
+ group, mask, match_mask);
if (fanotify_is_perm_event(mask)) {
/*
@@ -921,7 +950,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
}
event = fanotify_alloc_event(group, mask, data, data_type, dir,
- file_name, &fsid);
+ file_name, &fsid, match_mask);
ret = -ENOMEM;
if (unlikely(!event)) {
/*