Hi Shimoda-san,
On Wed, Jul 31, 2019 at 11:58 AM Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com wrote:
From: Geert Uytterhoeven, Sent: Wednesday, July 31, 2019 6:27 PM On Wed, Jul 31, 2019 at 11:04 AM Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com wrote:
Since the role_store() uses strncmp(), it's possible to refer out-of-memory if the sysfs data size is smaller than strlen("host"). This patch fixes it by using sysfs_streq() instead of strncmp().
Reported-by: Pavel Machek pavel@denx.de Fixes: 9bb86777fb71 ("phy: rcar-gen3-usb2: add sysfs for usb role swap") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com
Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be
Thank you for your review!
Just a record. The role_store() doesn't need to check the count because the sysfs_streq() checks the first argument is NULL or not.
Is that wat you mean? sysfs_streq() doesn't seem to check for NULL pointers.
Oops, sorry for unclear. I meant a NULL-terminated string, not NULL pointer.
OK.
Isn't the real reason that sysfs (kernfs) guarantees that the passed buffer is NUL-terminated?
I doesn't check in detail, but I assume so.
I have checked that recently, so it is OK.
Gr{oetje,eeting}s,
Geert