Re: [PATCH 2/2] fs/sysctl: remove redundant link check in proc_sys_link_fill_cache()

From: Danilo Krummrich
Date: Tue Feb 27 2018 - 18:01:20 EST


On 2018-02-27 23:59, Kees Cook wrote:
On Tue, Feb 27, 2018 at 2:43 PM, Danilo Krummrich
<danilokrummrich@xxxxxxxxxxxxx> wrote:
proc_sys_link_fill_cache() does not need to check whether we're
called for a link - it's already done by scan().

Signed-off-by: Danilo Krummrich <danilokrummrich@xxxxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index a0b6c647835e..7e7d9facb842 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -707,17 +707,16 @@ static bool proc_sys_link_fill_cache(struct file *file,
struct ctl_table *table)
{
bool ret = true;
+ int err = 0;
head = sysctl_head_grab(head);

if (IS_ERR(head))
return false;

- if (S_ISLNK(table->mode)) {
- /* It is not an error if we can not follow the link ignore it */
- int err = sysctl_follow_link(&head, &table);
- if (err)
- goto out;
- }
+ /* It is not an error if we can not follow the link ignore it */
+ sysctl_follow_link(&head, &table);

Shouldn't this be err = sysctl_follow_link... ? Otherwise I don't see
where err is used.

-Kees

Of course, thanks.
+ if (err)
+ goto out;

ret = proc_sys_fill_cache(file, ctx, head, table);
out:
--
2.14.1