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>
diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index ae8200f..1cc7038e 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -151,6 +151,13 @@
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) {