From: Eric Farman Date: Tue, 2 Jul 2019 18:09:28 +0000 (+0200) Subject: vfio-ccw: Fix the conversion of Format-0 CCWs to Format-1 X-Git-Tag: v5.3-rc1~216^2~3^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c382cbc6dbf513d73cf896ad43a3789ad42c2e2f;p=linux.git vfio-ccw: Fix the conversion of Format-0 CCWs to Format-1 When processing Format-0 CCWs, we use the "len" variable as the number of CCWs to convert to Format-1. But that variable contains zero here, and is not a meaningful CCW count until ccwchain_calc_length() returns. Since that routine requires and expects Format-1 CCWs to identify the chaining behavior, the format conversion must be done first. Convert the 2KB we copied even if it's more than we need. Fixes: 7f8e89a8f2fd ("vfio-ccw: Factor out the ccw0-to-ccw1 transition") Reported-by: Farhan Ali Signed-off-by: Eric Farman Reviewed-by: Cornelia Huck Message-Id: <20190702180928.18113-1-farman@linux.ibm.com> Signed-off-by: Cornelia Huck --- diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index a7b9dfd5b464..1d4c893ead23 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -431,7 +431,7 @@ static int ccwchain_handle_ccw(u32 cda, struct channel_program *cp) /* Convert any Format-0 CCWs to Format-1 */ if (!cp->orb.cmd.fmt) - convert_ccw0_to_ccw1(cp->guest_cp, len); + convert_ccw0_to_ccw1(cp->guest_cp, CCWCHAIN_LEN_MAX); /* Count the CCWs in the current chain */ len = ccwchain_calc_length(cda, cp);