fat: Fix possible null deref in fat_cache_add()

Reported-by: <dame_eugene@mail.ru> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
git-mirror · Apr 12, 2011 · 7003092 · 7003092
1 parent 384f5c9
commit 7003092
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/fs/fat/cache.c b/fs/fat/cache.c
@@ -151,6 +151,13 @@ static void fat_cache_add(struct inode *inode, struct fat_cache_id *new)
 			spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
 
 			tmp = fat_cache_alloc(inode);
+			if (!tmp) {
+				spin_lock(&MSDOS_I(inode)->cache_lru_lock);
+				MSDOS_I(inode)->nr_caches--;
+				spin_unlock(&MSDOS_I(inode)->cache_lru_lock);
+				return;
+			}
+
 			spin_lock(&MSDOS_I(inode)->cache_lru_lock);
 			cache = fat_cache_merge(inode, new);
 			if (cache != NULL) {