This is a note to let you know that I've just added the patch titled
fanotify: record either old name new name or both for FAN_RENAME
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
fanotify-record-either-old-name-new-name-or-both-for.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit eca1cf3e628ef0bf4d14f3a8821b7554e60292e4
Author: Amir Goldstein <amir73il@xxxxxxxxx>
Date: Mon Nov 29 22:15:35 2021 +0200
fanotify: record either old name new name or both for FAN_RENAME
[ Upstream commit 2bfbcccde6e7a787feabad4645f628f963fe0663 ]
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@xxxxxxxxx
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
[JK: Modified code to pass around only mask of mark types matching
generated event]
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index db81eab905442..14bc0f12cc9f3 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -284,8 +284,9 @@ static int fanotify_get_response(struct fsnotify_group *group,
*/
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)) {
/*
