From 6d5c9e79b726cc473d40e9cb60976dbe8e669624 Mon Sep 17 00:00:00 2001
From: Alon Zahavi <zahavi.alon@gmail.com>
Date: Mon, 15 Aug 2022 14:07:12 +0300
Subject: [PATCH] fs/ntfs3: Fix attr_punch_hole() null pointer derenference
The bug occours due to a misuse of `attr` variable instead of `attr_b`.
`attr` is being initialized as NULL, then being derenfernced
as `attr->res.data_size`.
This bug causes a crash of the ntfs3 driver itself,
If compiled directly to the kernel, it crashes the whole system.
Signed-off-by: Alon Zahavi <zahavi.alon@gmail.com>
Co-developed-by: Tal Lossos <tallossos@gmail.com>
Signed-off-by: Tal Lossos <tallossos@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
fs/ntfs3/attrib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 578c2bcfb1d93..63169529b52c4 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -2038,7 +2038,7 @@ int attr_punch_hole(struct ntfs_inode *ni, u64 vbo, u64 bytes, u32 *frame_size)
return -ENOENT;
if (!attr_b->non_res) {
- u32 data_size = le32_to_cpu(attr->res.data_size);
+ u32 data_size = le32_to_cpu(attr_b->res.data_size);
u32 from, to;
if (vbo > data_size)
--
2.30.2