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| author | Jan Kara <jack@suse.cz> | 2014-01-28 18:53:22 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2014-01-29 13:57:10 +0100 |
| commit | 83c0e1b442b488571f4fef4a91c2fe52eed6c705 (patch) | |
| tree | b29a85223f2e5e166f075266edb1bf2e0ef5cf57 /fs/notify/fanotify | |
| parent | 13116dfd13c8c9d60ea04ece13419af2de8e2e37 (diff) | |
| download | linux-stable-83c0e1b442b488571f4fef4a91c2fe52eed6c705.tar.gz linux-stable-83c0e1b442b488571f4fef4a91c2fe52eed6c705.tar.bz2 linux-stable-83c0e1b442b488571f4fef4a91c2fe52eed6c705.zip | |
fsnotify: Do not return merged event from fsnotify_add_notify_event()
The event returned from fsnotify_add_notify_event() cannot ever be used
safely as the event may be freed by the time the function returns (after
dropping notification_mutex). So change the prototype to just return
whether the event was added or merged into some existing event.
Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/notify/fanotify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index cc78e2fbc8e4..c7e5e8f54748 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -28,8 +28,7 @@ static bool should_merge(struct fsnotify_event *old_fsn, } /* and the list better be locked by something too! */ -static struct fsnotify_event *fanotify_merge(struct list_head *list, - struct fsnotify_event *event) +static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) { struct fsnotify_event *test_event; bool do_merge = false; @@ -43,7 +42,7 @@ static struct fsnotify_event *fanotify_merge(struct list_head *list, * one we should check for permission response. */ if (event->mask & FAN_ALL_PERM_EVENTS) - return NULL; + return 0; #endif list_for_each_entry_reverse(test_event, list, list) { @@ -54,10 +53,10 @@ static struct fsnotify_event *fanotify_merge(struct list_head *list, } if (!do_merge) - return NULL; + return 0; test_event->mask |= event->mask; - return test_event; + return 1; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS @@ -153,7 +152,6 @@ static int fanotify_handle_event(struct fsnotify_group *group, int ret = 0; struct fanotify_event_info *event; struct fsnotify_event *fsn_event; - struct fsnotify_event *notify_fsn_event; BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS); BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY); @@ -192,13 +190,11 @@ static int fanotify_handle_event(struct fsnotify_group *group, event->response = 0; #endif - notify_fsn_event = fsnotify_add_notify_event(group, fsn_event, - fanotify_merge); - if (notify_fsn_event) { + ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge); + if (ret) { /* Our event wasn't used in the end. Free it. */ fsnotify_destroy_event(group, fsn_event); - if (IS_ERR(notify_fsn_event)) - return PTR_ERR(notify_fsn_event); + ret = 0; } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS |