2024-03-09 21:48:43

by Kees Cook

Subject: [PATCH] exec: Simplify remove_arg_zero() error path

We don't need the "out" label any more, so remove "ret" and return
directly on error.

Signed-off-by: Kees Cook <[email protected]>
---
Cc: Eric Biederman <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
fs/exec.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 715e1a8aa4f0..e7d9d6ad980b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1720,7 +1720,6 @@ static int prepare_binprm(struct linux_binprm *bprm)
*/
int remove_arg_zero(struct linux_binprm *bprm)
{
- int ret = 0;
unsigned long offset;
char *kaddr;
struct page *page;
@@ -1731,10 +1730,8 @@ int remove_arg_zero(struct linux_binprm *bprm)
do {
offset = bprm->p & ~PAGE_MASK;
page = get_arg_page(bprm, bprm->p, 0);
- if (!page) {
- ret = -EFAULT;
- goto out;
- }
+ if (!page)
+ return -EFAULT;
kaddr = kmap_local_page(page);

for (; offset < PAGE_SIZE && kaddr[offset];
@@ -1748,8 +1745,7 @@ int remove_arg_zero(struct linux_binprm *bprm)
bprm->p++;
bprm->argc--;

-out:
- return ret;
+ return 0;
}
EXPORT_SYMBOL(remove_arg_zero);

--
2.34.1

2024-03-11 16:29:45

by Jan Kara

Subject: Re: [PATCH] exec: Simplify remove_arg_zero() error path

On Sat 09-03-24 13:48:30, Kees Cook wrote:
> We don't need the "out" label any more, so remove "ret" and return
> directly on error.
>
> Signed-off-by: Kees Cook <[email protected]>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> Cc: Eric Biederman <[email protected]>
> Cc: Alexander Viro <[email protected]>
> Cc: Christian Brauner <[email protected]>
> Cc: Jan Kara <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> fs/exec.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/fs/exec.c b/fs/exec.c
> index 715e1a8aa4f0..e7d9d6ad980b 100644
> --- a/fs/exec.c
> +++ b/fs/exec.c
> @@ -1720,7 +1720,6 @@ static int prepare_binprm(struct linux_binprm *bprm)
> */
> int remove_arg_zero(struct linux_binprm *bprm)
> {
> - int ret = 0;
> unsigned long offset;
> char *kaddr;
> struct page *page;
> @@ -1731,10 +1730,8 @@ int remove_arg_zero(struct linux_binprm *bprm)
> do {
> offset = bprm->p & ~PAGE_MASK;
> page = get_arg_page(bprm, bprm->p, 0);
> - if (!page) {
> - ret = -EFAULT;
> - goto out;
> - }
> + if (!page)
> + return -EFAULT;
> kaddr = kmap_local_page(page);
>
> for (; offset < PAGE_SIZE && kaddr[offset];
> @@ -1748,8 +1745,7 @@ int remove_arg_zero(struct linux_binprm *bprm)
> bprm->p++;
> bprm->argc--;
>
> -out:
> - return ret;
> + return 0;
> }
> EXPORT_SYMBOL(remove_arg_zero);
>
> --
> 2.34.1
>
--
Jan Kara <[email protected]>
SUSE Labs, CR