From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------
commit 66081a72517a131430dcf986775f3268aafcb546 upstream.
The warning check for duplicate sysfs entries can cause a buffer overflow
when printing the warning, as strcat() doesn't check buffer sizes.
Use strlcat() instead.
Since strlcat() doesn't return a pointer to the passed buffer, unlike
strcat(), I had to convert the nested concatenation in sysfs_add_one() to
an admittedly more obscure comma operator construct, to avoid emitting code
for the concatenation if CONFIG_BUG is disabled.
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
fs/sysfs/dir.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 590717861c7a..37d7153d3f72 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -400,20 +400,18 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
/**
* sysfs_pathname - return full path to sysfs dirent
* @sd: sysfs_dirent whose path we want
- * @path: caller allocated buffer
+ * @path: caller allocated buffer of size PATH_MAX
*
* Gives the name "/" to the sysfs_root entry; any path returned
* is relative to wherever sysfs is mounted.
- *
- * XXX: does no error checking on @path size
*/
static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
{
if (sd->s_parent) {
sysfs_pathname(sd->s_parent, path);
- strcat(path, "/");
+ strlcat(path, "/", PATH_MAX);
}
- strcat(path, sd->s_name);
+ strlcat(path, sd->s_name, PATH_MAX);
return path;
}
@@ -446,9 +444,11 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
char *path = kzalloc(PATH_MAX, GFP_KERNEL);
WARN(1, KERN_WARNING
"sysfs: cannot create duplicate filename '%s'\n",
- (path == NULL) ? sd->s_name :
- strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
- sd->s_name));
+ (path == NULL) ? sd->s_name
+ : (sysfs_pathname(acxt->parent_sd, path),
+ strlcat(path, "/", PATH_MAX),
+ strlcat(path, sd->s_name, PATH_MAX),
+ path));
kfree(path);
}
--
1.8.5.2
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html