[8/8] nfsd: Fix misuse of strlcpy
diff mbox series

Message ID b51141d12de77eb22101e81f9eb2c9cc44104d7a.1562283944.git.joe@perches.com
State New
Headers show
Series
  • treewide: correct misuses of strscpy/strlcpy
Related show

Commit Message

Joe Perches July 4, 2019, 11:57 p.m. UTC
Probable cut&paste typo - use the correct field size.

Signed-off-by: Joe Perches <joe@perches.com>
---
 fs/nfsd/nfs4idmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

J. Bruce Fields July 9, 2019, 3:14 a.m. UTC | #1
On Thu, Jul 04, 2019 at 04:57:48PM -0700, Joe Perches wrote:
> Probable cut&paste typo - use the correct field size.

Huh, that's been there forever, I wonder why we haven't seen crashes?
Oh, I see, name and authname both have the same size.

Anyway, makes sense, thanks.  Will apply for 5.3.

(Unless someone else is getting this; I didn't get copied on the rest of
the series.)

--b.

> 
> Signed-off-by: Joe Perches <joe@perches.com>
> ---
>  fs/nfsd/nfs4idmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
> index 2961016097ac..d1f285245af8 100644
> --- a/fs/nfsd/nfs4idmap.c
> +++ b/fs/nfsd/nfs4idmap.c
> @@ -83,7 +83,7 @@ ent_init(struct cache_head *cnew, struct cache_head *citm)
>  	new->type = itm->type;
>  
>  	strlcpy(new->name, itm->name, sizeof(new->name));
> -	strlcpy(new->authname, itm->authname, sizeof(new->name));
> +	strlcpy(new->authname, itm->authname, sizeof(new->authname));
>  }
>  
>  static void
> -- 
> 2.15.0
Joe Perches July 9, 2019, 5:40 a.m. UTC | #2
On Mon, 2019-07-08 at 23:14 -0400, J. Bruce Fields wrote:
> On Thu, Jul 04, 2019 at 04:57:48PM -0700, Joe Perches wrote:
> > Probable cut&paste typo - use the correct field size.
> 
> Huh, that's been there forever, I wonder why we haven't seen crashes?
> Oh, I see, name and authname both have the same size.
> 
> Anyway, makes sense, thanks.  Will apply for 5.3.
> 
> (Unless someone else is getting this; I didn't get copied on the rest of
> the series.)

It's generally hard to cc everyone on treewide fixes like this.

There's no good mechanism I know of.
vger mailing lists reject emails with too many addressees.

Do you have an opinion on adding the stracpy macro which
could avoid many of these defects?

---
 include/linux/string.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/linux/string.h b/include/linux/string.h
index 4deb11f7976b..ef01bd6f19df 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -35,6 +35,22 @@ ssize_t strscpy(char *, const char *, size_t);
 /* Wraps calls to strscpy()/memset(), no arch specific code required */
 ssize_t strscpy_pad(char *dest, const char *src, size_t count);
 
+#define stracpy(to, from)					\
+({								\
+	size_t size = ARRAY_SIZE(to);				\
+	BUILD_BUG_ON(!__same_type(typeof(*to), char));		\
+								\
+	strscpy(to, from, size);				\
+})
+
+#define stracpy_pad(to, from)					\
+({								\
+	size_t size = ARRAY_SIZE(to);				\
+	BUILD_BUG_ON(!__same_type(typeof(*to), char));		\
+								\
+	strscpy_pad(to, from, size);				\
+})
+
 #ifndef __HAVE_ARCH_STRCAT
 extern char * strcat(char *, const char *);
 #endif
J. Bruce Fields July 9, 2019, 11:33 p.m. UTC | #3
On Mon, Jul 08, 2019 at 10:40:50PM -0700, Joe Perches wrote:
> On Mon, 2019-07-08 at 23:14 -0400, J. Bruce Fields wrote:
> > On Thu, Jul 04, 2019 at 04:57:48PM -0700, Joe Perches wrote:
> > > Probable cut&paste typo - use the correct field size.
> > 
> > Huh, that's been there forever, I wonder why we haven't seen crashes?
> > Oh, I see, name and authname both have the same size.
> > 
> > Anyway, makes sense, thanks.  Will apply for 5.3.
> > 
> > (Unless someone else is getting this; I didn't get copied on the rest of
> > the series.)
> 
> It's generally hard to cc everyone on treewide fixes like this.
> 
> There's no good mechanism I know of.
> vger mailing lists reject emails with too many addressees.

Yeah.  I guess what I don't understand is why this patch is part of a
series at all.  It makes me wonder if there's some dependency I missed
or if the 0/8 mail actually asked somebody else to apply it.

Whatever, I guess I'm being silly, it clearly stands alone.  Applying
for 5.3.

> Do you have an opinion on adding the stracpy macro which
> could avoid many of these defects?

I don't have an opinion.

--b.


> ---
>  include/linux/string.h | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/include/linux/string.h b/include/linux/string.h
> index 4deb11f7976b..ef01bd6f19df 100644
> --- a/include/linux/string.h
> +++ b/include/linux/string.h
> @@ -35,6 +35,22 @@ ssize_t strscpy(char *, const char *, size_t);
>  /* Wraps calls to strscpy()/memset(), no arch specific code required */
>  ssize_t strscpy_pad(char *dest, const char *src, size_t count);
>  
> +#define stracpy(to, from)					\
> +({								\
> +	size_t size = ARRAY_SIZE(to);				\
> +	BUILD_BUG_ON(!__same_type(typeof(*to), char));		\
> +								\
> +	strscpy(to, from, size);				\
> +})
> +
> +#define stracpy_pad(to, from)					\
> +({								\
> +	size_t size = ARRAY_SIZE(to);				\
> +	BUILD_BUG_ON(!__same_type(typeof(*to), char));		\
> +								\
> +	strscpy_pad(to, from, size);				\
> +})
> +
>  #ifndef __HAVE_ARCH_STRCAT
>  extern char * strcat(char *, const char *);
>  #endif
> 
>

Patch
diff mbox series

diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 2961016097ac..d1f285245af8 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -83,7 +83,7 @@  ent_init(struct cache_head *cnew, struct cache_head *citm)
 	new->type = itm->type;
 
 	strlcpy(new->name, itm->name, sizeof(new->name));
-	strlcpy(new->authname, itm->authname, sizeof(new->name));
+	strlcpy(new->authname, itm->authname, sizeof(new->authname));
 }
 
 static void