5.15-stable review patch. If anyone has any objections, please let me know.
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From: Amir Goldstein amir73il@gmail.com
[ 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@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 Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/notify/fanotify/fanotify.c | 59 ++++++++++++++++++++++++++--------- 1 file changed, 44 insertions(+), 15 deletions(-)
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)) { /*