+ drivers-block-pktcdvdc-prevent-arbitrary-kernel-reads-in-ioctl.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     drivers/block/pktcdvd.c: prevent arbitrary kernel reads in ioctl
has been added to the -mm tree.  Its filename is
     drivers-block-pktcdvdc-prevent-arbitrary-kernel-reads-in-ioctl.patch

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------------------------------------------------------
Subject: drivers/block/pktcdvd.c: prevent arbitrary kernel reads in ioctl
From: Dan Rosenberg <drosenberg@vsecurity.com>

The PKT_CTRL_CMD_STATUS device ioctl retrieves a pointer to a
pktcdvd_device from the global pkt_devs array.  The index into this array
is provided directly by the user and is a signed integer, so the
comparison to ensure that it falls within the bounds of this array will
fail when provided with a negative index.

This can be used to read arbitrary kernel memory or cause a crash due to
an invalid pointer dereference.  This can be exploited by users with
permission to open /dev/pktcdvd/control (on many distributions, this is
readable by group "cdrom").  This patch fixes it.

Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/block/pktcdvd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN drivers/block/pktcdvd.c~drivers-block-pktcdvdc-prevent-arbitrary-kernel-reads-in-ioctl drivers/block/pktcdvd.c
--- a/drivers/block/pktcdvd.c~drivers-block-pktcdvdc-prevent-arbitrary-kernel-reads-in-ioctl
+++ a/drivers/block/pktcdvd.c
@@ -2370,7 +2370,7 @@ static void pkt_release_dev(struct pktcd
 
 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
 {
-	if (dev_minor >= MAX_WRITERS)
+	if ((unsigned int)dev_minor >= MAX_WRITERS)
 		return NULL;
 	return pkt_devs[dev_minor];
 }
_

Patches currently in -mm which might be from drosenberg@vsecurity.com are

origin.patch
sys_semctl-fix-kernel-stack-leakage.patch
drivers-block-pktcdvdc-prevent-arbitrary-kernel-reads-in-ioctl.patch
drivers-serial-serial_corec-prevent-reading-uninitialized-stack-memory.patch