diff mbox

tmpfs: clear S_ISGID when setting posix ACLs

Message ID 1483925688-8233-1-git-send-email-guzheng1@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Gu Zheng Jan. 9, 2017, 1:34 a.m. UTC
This change was missed the tmpfs modification in In CVE-2016-7097
commit 073931017b49 ("posix_acl: Clear SGID bit when setting
file permissions")
It can test by xfstest generic/375, which failed to clear
setgid bit in the following test case on tmpfs:

  touch $testfile
  chown 100:100 $testfile
  chmod 2755 $testfile
  _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile

Signed-off-by: Gu Zheng <guzheng1@huawei.com>
---
 fs/posix_acl.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Jan Kara Jan. 10, 2017, 8:03 a.m. UTC | #1
On Mon 09-01-17 09:34:48, Gu Zheng wrote:
> This change was missed the tmpfs modification in In CVE-2016-7097
> commit 073931017b49 ("posix_acl: Clear SGID bit when setting
> file permissions")
> It can test by xfstest generic/375, which failed to clear
> setgid bit in the following test case on tmpfs:
> 
>   touch $testfile
>   chown 100:100 $testfile
>   chmod 2755 $testfile
>   _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile
> 
> Signed-off-by: Gu Zheng <guzheng1@huawei.com>

Thanks. The patch looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Al, will you please merge it? Thanks!

								Honza

> ---
>  fs/posix_acl.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/posix_acl.c b/fs/posix_acl.c
> index 5955220..d014dff 100644
> --- a/fs/posix_acl.c
> +++ b/fs/posix_acl.c
> @@ -922,11 +922,10 @@ int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
>  	int error;
>  
>  	if (type == ACL_TYPE_ACCESS) {
> -		error = posix_acl_equiv_mode(acl, &inode->i_mode);
> -		if (error < 0)
> -			return 0;
> -		if (error == 0)
> -			acl = NULL;
> +		error = posix_acl_update_mode(inode,
> +				&inode->i_mode, &acl);
> +		if (error)
> +			return error;
>  	}
>  
>  	inode->i_ctime = current_time(inode);
> -- 
> 2.5.0
>
Al Viro Jan. 10, 2017, 8:12 a.m. UTC | #2
On Tue, Jan 10, 2017 at 09:03:01AM +0100, Jan Kara wrote:
> On Mon 09-01-17 09:34:48, Gu Zheng wrote:
> > This change was missed the tmpfs modification in In CVE-2016-7097
> > commit 073931017b49 ("posix_acl: Clear SGID bit when setting
> > file permissions")
> > It can test by xfstest generic/375, which failed to clear
> > setgid bit in the following test case on tmpfs:
> > 
> >   touch $testfile
> >   chown 100:100 $testfile
> >   chmod 2755 $testfile
> >   _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile
> > 
> > Signed-off-by: Gu Zheng <guzheng1@huawei.com>
> 
> Thanks. The patch looks good. You can add:
> 
> Reviewed-by: Jan Kara <jack@suse.cz>
> 
> Al, will you please merge it? Thanks!

Already applied, actually...
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diff mbox

Patch

diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 5955220..d014dff 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -922,11 +922,10 @@  int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 	int error;
 
 	if (type == ACL_TYPE_ACCESS) {
-		error = posix_acl_equiv_mode(acl, &inode->i_mode);
-		if (error < 0)
-			return 0;
-		if (error == 0)
-			acl = NULL;
+		error = posix_acl_update_mode(inode,
+				&inode->i_mode, &acl);
+		if (error)
+			return error;
 	}
 
 	inode->i_ctime = current_time(inode);