Upon TUNSETSNDBUF, macvtap reads the requested sndbuf size into a local variable u. commit 39ec7de7092b ("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 <da...@davemloft.net> Fixes: 39ec7de7092b ("macvtap: fix uninitialized access on TUNSETIFF") Reported-by: Mark A. Peloquin Bisected-by: Matthew Rosato <mjros...@linux.vnet.ibm.com> Reported-by: Christian Borntraeger <borntrae...@de.ibm.com> Signed-off-by: Michael S. Tsirkin <m...@redhat.com> --- This patch probably makes sense on stable. drivers/net/macvtap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index edd7734..248478c 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -1111,10 +1111,10 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd, return 0; case TUNSETSNDBUF: - if (get_user(u, up)) + if (get_user(s, sp)) return -EFAULT; - q->sk.sk_sndbuf = u; + q->sk.sk_sndbuf = s; return 0; case TUNGETVNETHDRSZ: -- MST -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html