macvtap: fix TUNSETSNDBUF values > 64k

[ Upstream commit 3ea79249e8 ]

Upon TUNSETSNDBUF,  macvtap reads the requested sndbuf size into
a local variable u.
commit 39ec7de709 ("macvtap: fix uninitialized access on
TUNSETIFF") changed its type to u16 (which is the right thing to
do for all other macvtap ioctls), breaking all values > 64k.

The value of TUNSETSNDBUF is actually a signed 32 bit integer, so
the right thing to do is to read it into an int.

Cc: David S. Miller <davem@davemloft.net>
Fixes: 39ec7de709 ("macvtap: fix uninitialized access on TUNSETIFF")
Reported-by: Mark A. Peloquin
Bisected-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by:  Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael S. Tsirkin 2015-09-18 13:41:09 +03:00 • committed by Greg Kroah-Hartman
commit cf9cf6bc25