ntfs3: Fix attr_punch_hole() null pointer derenference

[PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference

Posted by Alon Zahavi 3 years, 7 months ago

From: Alon Zahavi <zahavi.alon@gmail.com>

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>
---
 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 e8c00dda42ad..4e74bc8f01ed 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -1949,7 +1949,7 @@ 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)
-- 
2.25.1

Re: [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference

Posted by SeongJae Park 3 years, 2 months ago

Hello,

On Mon, 15 Aug 2022 14:07:12 +0300 Alon Zahavi <zahavi.alon@gmail.com> wrote:

> From: Alon Zahavi <zahavi.alon@gmail.com>
> 
> 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>

This patch has now merged in mainline as
6d5c9e79b726cc473d40e9cb60976dbe8e669624.  stable@, could you please merge this
in stable kernels?

Fixes: be71b5cba2e64 ("fs/ntfs3: Add attrib operations") # 5.14


Thanks,
SJ

> ---
>  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 e8c00dda42ad..4e74bc8f01ed 100644
> --- a/fs/ntfs3/attrib.c
> +++ b/fs/ntfs3/attrib.c
> @@ -1949,7 +1949,7 @@ 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)
> -- 
> 2.25.1
> 
>

Re: [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference

Posted by Greg KH 3 years, 2 months ago

On Tue, Jan 17, 2023 at 08:21:36PM +0000, SeongJae Park wrote:
> Hello,
> 
> On Mon, 15 Aug 2022 14:07:12 +0300 Alon Zahavi <zahavi.alon@gmail.com> wrote:
> 
> > From: Alon Zahavi <zahavi.alon@gmail.com>
> > 
> > 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>
> 
> This patch has now merged in mainline as
> 6d5c9e79b726cc473d40e9cb60976dbe8e669624.  stable@, could you please merge this
> in stable kernels?
> 
> Fixes: be71b5cba2e64 ("fs/ntfs3: Add attrib operations") # 5.14
> 

Now queued up, thanks.

greg k-h

Re: [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference

Posted by SeongJae Park 3 years, 2 months ago

Hello,

On Mon, 15 Aug 2022 14:07:12 +0300 Alon Zahavi <zahavi.alon@gmail.com> wrote:

> From: Alon Zahavi <zahavi.alon@gmail.com>
>
> 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>

This patch has now merged in mainline as
6d5c9e79b726cc473d40e9cb60976dbe8e669624.  stable@, could you please merge this
in stable kernels?

Fixes: be71b5cba2e64 ("fs/ntfs3: Add attrib operations") # 5.14


Thanks,
SJ

> ---
>  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 e8c00dda42ad..4e74bc8f01ed 100644
> --- a/fs/ntfs3/attrib.c
> +++ b/fs/ntfs3/attrib.c
> @@ -1949,7 +1949,7 @@ 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)
> --
> 2.25.1
>
>

Re: [PATCH] ntfs3: Fix attr_punch_hole() null pointer derenference

Posted by Konstantin Komarov 3 years, 6 months ago


On 8/15/22 14:07, Alon Zahavi wrote:
> From: Alon Zahavi <zahavi.alon@gmail.com>
> 
> 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>
> ---
>   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 e8c00dda42ad..4e74bc8f01ed 100644
> --- a/fs/ntfs3/attrib.c
> +++ b/fs/ntfs3/attrib.c
> @@ -1949,7 +1949,7 @@ 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)

Applied, thanks!