2023-01-24 11:16:01

by Denis Arefev

Subject: [PATCH] smackfs: Added check catlen

If the catlen is 0, the memory for the netlbl_lsm_catmap
structure must be allocated anyway, otherwise the check of
such rules is not completed correctly.

Signed-off-by: Denis Arefev <[email protected]>
---
security/smack/smackfs.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 4b58526450d4..d45f4395a6ce 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -830,7 +830,7 @@ static int smk_open_cipso(struct inode *inode, struct file *file)
static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
size_t count, loff_t *ppos, int format)
{
- struct netlbl_lsm_catmap *old_cat;
+ struct netlbl_lsm_catmap *old_cat, *new_cat = NULL;
struct smack_known *skp;
struct netlbl_lsm_secattr ncats;
char mapcatset[SMK_CIPSOLEN];
@@ -917,8 +917,19 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,

smack_catset_bit(cat, mapcatset);
}
-
- rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
+ ncats.flags = 0;
+ if (catlen == 0) {
+ ncats.attr.mls.cat = NULL;
+ ncats.attr.mls.lvl = maplevel;
+ new_cat = netlbl_catmap_alloc(GFP_ATOMIC);
+ if (new_cat)
+ new_cat->next = ncats.attr.mls.cat;
+ ncats.attr.mls.cat = new_cat;
+ skp->smk_netlabel.flags &= ~(1U << 3);
+ rc = 0;
+ } else {
+ rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
+ }
if (rc >= 0) {
old_cat = skp->smk_netlabel.attr.mls.cat;
skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat;
--
2.25.1

2023-01-30 17:48:14

by Casey Schaufler

Subject: Re: [PATCH] smackfs: Added check catlen

On 1/24/2023 2:50 AM, Denis Arefev wrote:
> If the catlen is 0, the memory for the netlbl_lsm_catmap
> structure must be allocated anyway, otherwise the check of
> such rules is not completed correctly.
>
> Signed-off-by: Denis Arefev <[email protected]>

Added to smack-next. Thank you.

> ---
> security/smack/smackfs.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
> index 4b58526450d4..d45f4395a6ce 100644
> --- a/security/smack/smackfs.c
> +++ b/security/smack/smackfs.c
> @@ -830,7 +830,7 @@ static int smk_open_cipso(struct inode *inode, struct file *file)
> static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
> size_t count, loff_t *ppos, int format)
> {
> - struct netlbl_lsm_catmap *old_cat;
> + struct netlbl_lsm_catmap *old_cat, *new_cat = NULL;
> struct smack_known *skp;
> struct netlbl_lsm_secattr ncats;
> char mapcatset[SMK_CIPSOLEN];
> @@ -917,8 +917,19 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
>
> smack_catset_bit(cat, mapcatset);
> }
> -
> - rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
> + ncats.flags = 0;
> + if (catlen == 0) {
> + ncats.attr.mls.cat = NULL;
> + ncats.attr.mls.lvl = maplevel;
> + new_cat = netlbl_catmap_alloc(GFP_ATOMIC);
> + if (new_cat)
> + new_cat->next = ncats.attr.mls.cat;
> + ncats.attr.mls.cat = new_cat;
> + skp->smk_netlabel.flags &= ~(1U << 3);
> + rc = 0;
> + } else {
> + rc = smk_netlbl_mls(maplevel, mapcatset, &ncats, SMK_CIPSOLEN);
> + }
> if (rc >= 0) {
> old_cat = skp->smk_netlabel.attr.mls.cat;
> skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat;