linux-kernel - [PATCH 3.4 033/146] scsi: storvsc: Fix a bug in copy_from_bounce

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1442307861-32031-33-git-send-email-lizf@kernel.org>
Date:	Tue, 15 Sep 2015 17:02:28 +0800
From:	lizf@...nel.org
To:	stable@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	James Bottomley <JBottomley@...n.com>,
	Zefan Li <lizefan@...wei.com>
Subject: [PATCH 3.4 033/146] scsi: storvsc: Fix a bug in copy_from_bounce_buffer()

From: "K. Y. Srinivasan" <kys@...rosoft.com>

3.4.109-rc1 review patch.  If anyone has any objections, please let me know.

------------------


commit 8de580742fee8bc34d116f57a20b22b9a5f08403 upstream.

We may exit this function without properly freeing up the maapings
we may have acquired. Fix the bug.

Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
Reviewed-by: Long Li <longli@...rosoft.com>
Signed-off-by: James Bottomley <JBottomley@...n.com>
Signed-off-by: Zefan Li <lizefan@...wei.com>
---
 drivers/scsi/storvsc_drv.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index a0df0fb..4ae7769 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -610,21 +610,22 @@ static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 			if (bounce_sgl[j].length == PAGE_SIZE) {
 				/* full..move to next entry */
 				sg_kunmap_atomic(bounce_addr);
+				bounce_addr = 0;
 				j++;
+			}
 
-				/* if we need to use another bounce buffer */
-				if (srclen || i != orig_sgl_count - 1)
-					bounce_addr = sg_kmap_atomic(bounce_sgl,j);
+			/* if we need to use another bounce buffer */
+			if (srclen && bounce_addr == 0)
+				bounce_addr = sg_kmap_atomic(bounce_sgl, j);
 
-			} else if (srclen == 0 && i == orig_sgl_count - 1) {
-				/* unmap the last bounce that is < PAGE_SIZE */
-				sg_kunmap_atomic(bounce_addr);
-			}
 		}
 
 		sg_kunmap_atomic(src_addr - orig_sgl[i].offset);
 	}
 
+	if (bounce_addr)
+		sg_kunmap_atomic(bounce_addr);
+
 	local_irq_restore(flags);
 
 	return total_copied;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/