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authorDan Rosenberg <drosenberg@vsecurity.com>2010-09-27 12:30:28 -0400
committerAndi Kleen <ak@linux.intel.com>2010-12-14 23:40:18 +0100
commiteb015d662b1831e61ce9610da234565f8349311b (patch)
treef07493e5e2e1da26a628c7b4a2d2c8cc10dea154
parent6efba844d4ad8783c46ee2477344bfd87f737325 (diff)
Fix pktcdvd ioctl dev_minor range check
Upstream 252a52aa4fa22a668f019e55b3aac3ff71ec1c29 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"). Signed-off-by: Dan Rosenberg <dan.j.rosenberg@gmail.com> [ Rather than add a cast, just make the function take the right type -Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andi Kleen <ak@linux.intel.com>
-rw-r--r--drivers/block/pktcdvd.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 8a549db2aa78..8403fd54cadb 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2368,7 +2368,7 @@ static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
pkt_shrink_pktlist(pd);
}
-static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
+static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
{
if (dev_minor >= MAX_WRITERS)
return NULL;