Re: [PATCH] ima: Replacing deprecated strlcpy with strscpy ~~~~~~~~~ Replace

Reply-To: 
In-Reply-To: [off-list ref]

On Fri, Feb 19, 2021 at 02:10:38PM +0530, Palash Oswal wrote:

The strlcpy() function is unsafe in that the source buffer length
is unbounded or possibly be non NULL terminated. This can cause
memory over-reads, crashes, etc.

Link: https://github.com/KSPP/linux/issues/89
Signed-off-by: Palash Oswal <redacted>

The long description does not explain what the commit does, and
does not include any details about deprecation of strlcpy(), which
at least I'm not aware of.

I don't think *length* ever is NULL terminated. The first sentence
is somewhat weird. Also strlcpy() does have a bounds check.

Generally, the description and reasoning is sloppy to say the
least.

/Jarkko

Apologies for the in-accurate description. This patch is covered under
the patch-set by Romain Perier ( https://lkml.org/lkml/2021/2/22/739 )
and can be disregarded.

Best Regards,
Palash

On Fri, Feb 19, 2021 at 11:09 PM Jarkko Sakkinen [off-list ref] wrote:

Reply-To:
In-Reply-To: [off-list ref]

On Fri, Feb 19, 2021 at 02:10:38PM +0530, Palash Oswal wrote:

quoted

The strlcpy() function is unsafe in that the source buffer length
is unbounded or possibly be non NULL terminated. This can cause
memory over-reads, crashes, etc.

Link: https://github.com/KSPP/linux/issues/89
Signed-off-by: Palash Oswal <redacted>

The long description does not explain what the commit does, and
does not include any details about deprecation of strlcpy(), which
at least I'm not aware of.

I don't think *length* ever is NULL terminated. The first sentence
is somewhat weird. Also strlcpy() does have a bounds check.

Generally, the description and reasoning is sloppy to say the
least.

/Jarkko

quoted

---
 security/integrity/ima/ima_api.c    | 2 +-
 security/integrity/ima/ima_policy.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 1dd70dc68ffd..2f3b8257181d 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c

@@ -399,7 +399,7 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf)
      }

      if (!pathname) {
-             strlcpy(namebuf, path->dentry->d_name.name, NAME_MAX);
+             strscpy(namebuf, path->dentry->d_name.name, NAME_MAX);
              pathname = namebuf;
      }

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index 9b45d064a87d..010839aef6ba 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c

@@ -791,7 +791,7 @@ static int __init ima_init_arch_policy(void)
              char rule[255];
              int result;

-             result = strlcpy(rule, *rules, sizeof(rule));
+             strscpy(rule, *rules, sizeof(rule));

              INIT_LIST_HEAD(&arch_policy_entry[i].list);
              result = ima_parse_rule(rule, &arch_policy_entry[i]);

base-commit: f6692213b5045dc461ce0858fb18cf46f328c202
--
2.27.0