UBIFS: Fix potential integer overflow in allocation

commit 353748a359f1821ee934afc579cf04572406b420 upstream.

There is potential for the size and len fields in ubifs_data_node to be
too large causing either a negative value for the length fields or an
integer overflow leading to an incorrect memory allocation. Likewise,
when the len field is small, an integer underflow may occur.

Signed-off-by: Silvio Cesare <silvio.cesare@gmail.com>
Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
index 7d764e3..504658f 100644 (file)
--- a/fs/ubifs/journal.c
+++ b/fs/ubifs/journal.c
@@ -1265,7 +1265,7 @@ static int recomp_data_node(const struct ubifs_info *c,
        int err, len, compr_type, out_len;
 
        out_len = le32_to_cpu(dn->size);
-       buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
+       buf = kmalloc_array(out_len, WORST_COMPR_FACTOR, GFP_NOFS);
        if (!buf)
                return -ENOMEM;