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From:   Peilin Ye <yepeilin.cs@gmail.com>
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        Magnus Karlsson <magnus.karlsson@intel.com>,
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Cc:     Peilin Ye <yepeilin.cs@gmail.com>,
        Dan Carpenter <dan.carpenter@oracle.com>,
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Subject: [Linux-kernel-mentees] [PATCH net] xdp: Prevent kernel-infoleak in xsk_getsockopt()
Date:   Mon, 27 Jul 2020 22:28:59 -0400
Message-Id: <20200728022859.381819-1-yepeilin.cs@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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xsk_getsockopt() is copying uninitialized stack memory to userspace when
`extra_stats` is `false`. Fix it by initializing `stats` with memset().

Cc: stable@vger.kernel.org
Fixes: 8aa5a33578e9 ("xsk: Add new statistics")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
 net/xdp/xsk.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 26e3bba8c204..acf001908a0d 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -844,6 +844,8 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
 		bool extra_stats = true;
 		size_t stats_size;
 
+		memset(&stats, 0, sizeof(stats));
+
 		if (len < sizeof(struct xdp_statistics_v1)) {
 			return -EINVAL;
 		} else if (len < sizeof(stats)) {
-- 
2.25.1