From: Alexander Potapenko <glider@google.com>
Date: Fri, 18 May 2018 14:23:18 +0000 (+0200)
Subject: scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ad2518320bc440ed3db072e2444a1bb226a9cf7a;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

scsi: sg: allocate with __GFP_ZERO in sg_build_indirect()

commit a45b599ad808c3c982fdcdc12b0b8611c2f92824 upstream.

This shall help avoid copying uninitialized memory to the userspace when
calling ioctl(fd, SG_IO) with an empty command.

Reported-by: syzbot+7d26fc1eea198488deab@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index f61b37109e5c..0f81d739f9e9 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1893,7 +1893,7 @@ retry:
 		num = (rem_sz > scatter_elem_sz_prev) ?
 			scatter_elem_sz_prev : rem_sz;
 
-		schp->pages[k] = alloc_pages(gfp_mask, order);
+		schp->pages[k] = alloc_pages(gfp_mask | __GFP_ZERO, order);
 		if (!schp->pages[k])
 			goto out;