2019-04-15 18:00:07

by Wenwen Wang

Subject: [PATCH v2] udf: fix an uninitialized read bug and remove dead code

In udf_lookup(), the pointer 'fi' is a local variable initialized by the
return value of the function call udf_find_entry(). However, if the macro
'UDF_RECOVERY' is defined, this variable will become uninitialized if the
else branch is not taken, which can potentially cause incorrect results in
the following execution.

To fix this issue, this patch drops the whole code in the ifdef
'UDF_RECOVERY' region, as it is dead code.

Signed-off-by: Wenwen Wang <[email protected]>
---
fs/udf/namei.c | 15 ---------------
1 file changed, 15 deletions(-)

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 58cc241..77b6d89 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -304,21 +304,6 @@ static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
if (dentry->d_name.len > UDF_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);

-#ifdef UDF_RECOVERY
- /* temporary shorthand for specifying files by inode number */
- if (!strncmp(dentry->d_name.name, ".B=", 3)) {
- struct kernel_lb_addr lb = {
- .logicalBlockNum = 0,
- .partitionReferenceNum =
- simple_strtoul(dentry->d_name.name + 3,
- NULL, 0),
- };
- inode = udf_iget(dir->i_sb, lb);
- if (IS_ERR(inode))
- return inode;
- } else
-#endif /* UDF_RECOVERY */
-
fi = udf_find_entry(dir, &dentry->d_name, &fibh, &cfi);
if (IS_ERR(fi))
return ERR_CAST(fi);
--
2.7.4

2019-04-17 11:16:49

by Jan Kara

Subject: Re: [PATCH v2] udf: fix an uninitialized read bug and remove dead code

On Mon 15-04-19 12:58:06, Wenwen Wang wrote:
> In udf_lookup(), the pointer 'fi' is a local variable initialized by the
> return value of the function call udf_find_entry(). However, if the macro
> 'UDF_RECOVERY' is defined, this variable will become uninitialized if the
> else branch is not taken, which can potentially cause incorrect results in
> the following execution.
>
> To fix this issue, this patch drops the whole code in the ifdef
> 'UDF_RECOVERY' region, as it is dead code.
>
> Signed-off-by: Wenwen Wang <[email protected]>

Thanks for the patch. I've added it to my tree.

Honza

> ---
> fs/udf/namei.c | 15 ---------------
> 1 file changed, 15 deletions(-)
>
> diff --git a/fs/udf/namei.c b/fs/udf/namei.c
> index 58cc241..77b6d89 100644
> --- a/fs/udf/namei.c
> +++ b/fs/udf/namei.c
> @@ -304,21 +304,6 @@ static struct dentry *udf_lookup(struct inode *dir, struct dentry *dentry,
> if (dentry->d_name.len > UDF_NAME_LEN)
> return ERR_PTR(-ENAMETOOLONG);
>
> -#ifdef UDF_RECOVERY
> - /* temporary shorthand for specifying files by inode number */
> - if (!strncmp(dentry->d_name.name, ".B=", 3)) {
> - struct kernel_lb_addr lb = {
> - .logicalBlockNum = 0,
> - .partitionReferenceNum =
> - simple_strtoul(dentry->d_name.name + 3,
> - NULL, 0),
> - };
> - inode = udf_iget(dir->i_sb, lb);
> - if (IS_ERR(inode))
> - return inode;
> - } else
> -#endif /* UDF_RECOVERY */
> -
> fi = udf_find_entry(dir, &dentry->d_name, &fibh, &cfi);
> if (IS_ERR(fi))
> return ERR_CAST(fi);
> --
> 2.7.4
>
>
--
Jan Kara <[email protected]>
SUSE Labs, CR