From 9cca110cf8bb0653b423dba7a7c4cc23ccf91b28 Mon Sep 17 00:00:00 2001 From: Alon Zahavi Date: Mon, 15 Aug 2022 14:07:12 +0300 Subject: [PATCH] fs/ntfs3: Fix attr_punch_hole() null pointer derenference commit 6d5c9e79b726cc473d40e9cb60976dbe8e669624 upstream. 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 Co-developed-by: Tal Lossos Signed-off-by: Tal Lossos Signed-off-by: Konstantin Komarov Signed-off-by: Greg Kroah-Hartman --- 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 42af83b..321d55b 100644 --- a/fs/ntfs3/attrib.c +++ b/fs/ntfs3/attrib.c @@ -1967,7 +1967,7 @@ 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) -- 2.7.4