When converting an inline directory to a regular one, f2fs is leaking
uninitialized memory to disk because it doesn't initialize the entire
directory block. Fix this by zero-initializing the block.
This bug was introduced by commit 4ec17d688d ("f2fs: avoid unneeded
initializing when converting inline dentry"), which didn't consider the
security implications of leaking uninitialized memory to disk.
This was found by running xfstest generic/435 on a KMSAN-enabled kernel.
Fixes: 4ec17d688d ("f2fs: avoid unneeded initializing when converting inline dentry")
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
9a5571cff4