2023-08-13 08:39:41

by Manas Ghandat

Subject: [PATCH v4] ntfs : fix shift-out-of-bounds in ntfs_iget

Currently there is not check for ni->itype.compressed.block_size when
a->data.non_resident.compression_unit is present and NInoSparse(ni) is
true. Added the required check to calculation of block size.

Signed-off-by: Manas Ghandat <[email protected]>
Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=4768a8f039aa677897d0
Fix-commit-ID: upstream f40ddce88593482919761f74910f42f4b84c004b
---
V3 -> V4: Fix description
V2 -> V3: Fix patching issue.
V1 -> V2: Cleaned up coding style.

fs/ntfs/inode.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 6c3f38d66579..a657322874ed 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -1077,6 +1077,15 @@ static int ntfs_read_locked_inode(struct inode *vi)
goto unm_err_out;
}
if (a->data.non_resident.compression_unit) {
+ if (a->data.non_resident.compression_unit +
+ vol->cluster_size_bits > 32) {
+ ntfs_error(vi->i_sb,
+ "Found non-standard compression unit (%u). Cannot handle this.",
+ a->data.non_resident.compression_unit
+ );
+ err = -EOPNOTSUPP;
+ goto unm_err_out;
+ }
ni->itype.compressed.block_size = 1U <<
(a->data.non_resident.
compression_unit +
--
2.37.2

2023-08-14 06:22:35

by Namjae Jeon

Subject: Re: [PATCH v4] ntfs : fix shift-out-of-bounds in ntfs_iget

2023-08-13 14:59 GMT+09:00, Manas Ghandat <[email protected]>:
Hi,
> Currently there is not check for ni->itype.compressed.block_size when
> a->data.non_resident.compression_unit is present and NInoSparse(ni) is
> true. Added the required check to calculation of block size.
>
> Signed-off-by: Manas Ghandat <[email protected]>
> Reported-by: [email protected]
> Closes: https://syzkaller.appspot.com/bug?extid=4768a8f039aa677897d0
> Fix-commit-ID: upstream f40ddce88593482919761f74910f42f4b84c004b
> ---
> V3 -> V4: Fix description
> V2 -> V3: Fix patching issue.
> V1 -> V2: Cleaned up coding style.
>
> fs/ntfs/inode.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
> index 6c3f38d66579..a657322874ed 100644
> --- a/fs/ntfs/inode.c
> +++ b/fs/ntfs/inode.c
> @@ -1077,6 +1077,15 @@ static int ntfs_read_locked_inode(struct inode *vi)
> goto unm_err_out;
> }
> if (a->data.non_resident.compression_unit) {
> + if (a->data.non_resident.compression_unit +
> + vol->cluster_size_bits > 32) {
> + ntfs_error(vi->i_sb,
> + "Found non-standard compression unit (%u). Cannot handle this.",
> + a->data.non_resident.compression_unit
> + );
> + err = -EOPNOTSUPP;
> + goto unm_err_out;
> + }
compression_unit seems to be used when the ntfs inode is compressed.
And it should be either 0 or 4 value. So, I think we can set related
compression block variables of ntfs inode only when ni is
NInoCompressed like this... Anton, Am I missing something ?

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index efe0602b4e51..e5a7d81d575b 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -1076,7 +1076,8 @@ static int ntfs_read_locked_inode(struct inode *vi)
err = -EOPNOTSUPP;
goto unm_err_out;
}
- if (a->data.non_resident.compression_unit) {
+ if (NInoCompressed(ni) &&
+ a->data.non_resident.compression_unit) {
ni->itype.compressed.block_size = 1U <<
(a->data.non_resident.
compression_unit +

> ni->itype.compressed.block_size = 1U <<
> (a->data.non_resident.
> compression_unit +
> --
> 2.37.2
>
>