[PATCH 3.13.y-ckt 011/156] USB: usbfs: don't leak kernel data in siginfo

From: Kamal Mostafa
Date: Tue Apr 07 2015 - 19:38:36 EST

3.13.11-ckt19 -stable review patch. If anyone has any objections, please let me know.


From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.

When a signal is delivered, the information in the siginfo structure
is copied to userspace. Good security practice dicatates that the
unused fields in this structure should be initialized to 0 so that
random kernel stack data isn't exposed to the user. This patch adds
such an initialization to the two places where usbfs raises signals.

Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Dave Mielke <dave@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
drivers/usb/core/devio.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 74185cc..4c2c65b 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -501,6 +501,7 @@ static void async_completed(struct urb *urb)
as->status = urb->status;
signr = as->signr;
if (signr) {
+ memset(&sinfo, 0, sizeof(sinfo));
sinfo.si_signo = as->signr;
sinfo.si_errno = as->status;
sinfo.si_code = SI_ASYNCIO;
@@ -2227,6 +2228,7 @@ static void usbdev_remove(struct usb_device *udev)
if (ps->discsignr) {
+ memset(&sinfo, 0, sizeof(sinfo));
sinfo.si_signo = ps->discsignr;
sinfo.si_errno = EPIPE;
sinfo.si_code = SI_ASYNCIO;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/