drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl
authorDan Carpenter <dan.carpenter@oracle.com>
Tue, 14 May 2019 22:47:03 +0000 (15:47 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 16 May 2019 17:43:47 +0000 (19:43 +0200)
commit71e29a15b4babddba1a6faab6d98d2dcce1cd0ff
treefb3bdc66b13ddafff02152bfcd364747536ef7a4
parentb51cbe62e859ab198f8a9077d2c9d2b7ad767a5b
drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl

commit 6a024330650e24556b8a18cc654ad00cfecf6c6c upstream.

The "param.count" value is a u64 thatcomes from the user.  The code
later in the function assumes that param.count is at least one and if
it's not then it leads to an Oops when we dereference the ZERO_SIZE_PTR.

Also the addition can have an integer overflow which would lead us to
allocate a smaller "pages" array than required.  I can't immediately
tell what the possible run times implications are, but it's safest to
prevent the overflow.

Link: http://lkml.kernel.org/r/20181218082129.GE32567@kadam
Fixes: 6db7199407ca ("drivers/virt: introduce Freescale hypervisor management driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/virt/fsl_hypervisor.c