[PATCH] bna: ethtool: Avoid reading past end of buffer

[PATCH] bna: ethtool: Avoid reading past end of buffer

[Loic]

Hello,

Please picked up this patch for linux 4.4 and 4.9.
Compiled/tested without problem.

Thank.

[ Upstream commit 4dc69c1c1fff2f587f8e737e70b4a4e7565a5c94 ]

From: Kees Cook <keescook@chromium.org>
Date: Fri, 5 May 2017 15:30:23 -0700
Subject: [PATCH] bna: ethtool: Avoid reading past end of buffer

Using memcpy() from a string that is shorter than the length copied means
the destination buffer is being filled with arbitrary data from the kernel
rodata segment. Instead, use strncpy() which will fill the trailing bytes
with zeros.

This was found with the future CONFIG_FORTIFY_SOURCE feature.

Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/brocade/bna/bnad_ethtool.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/brocade/bna/bnad_ethtool.c b/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
index 286593922139e..31032de5843b1 100644
--- a/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
+++ b/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
@@ -547,8 +547,8 @@ bnad_get_strings(struct net_device *netdev, u32 stringset, u8 *string)
 		for (i = 0; i < BNAD_ETHTOOL_STATS_NUM; i++) {
 			BUG_ON(!(strlen(bnad_net_stats_strings[i]) <
 				   ETH_GSTRING_LEN));
-			memcpy(string, bnad_net_stats_strings[i],
-			       ETH_GSTRING_LEN);
+			strncpy(string, bnad_net_stats_strings[i],
+				ETH_GSTRING_LEN);
 			string += ETH_GSTRING_LEN;
 		}
 		bmap = bna_tx_rid_mask(&bnad->bna);

Re: [PATCH] bna: ethtool: Avoid reading past end of buffer

[Sasha Levin]

On Fri, Nov 09, 2018 at 01:52:57PM +0100, Loic wrote:
>Hello,
>
>Please picked up this patch for linux 4.4 and 4.9.
>Compiled/tested without problem.
>
>Thank.
>
>[ Upstream commit 4dc69c1c1fff2f587f8e737e70b4a4e7565a5c94 ]
>
>From: Kees Cook <keescook@chromium.org>
>Date: Fri, 5 May 2017 15:30:23 -0700
>Subject: [PATCH] bna: ethtool: Avoid reading past end of buffer
>
>Using memcpy() from a string that is shorter than the length copied means
>the destination buffer is being filled with arbitrary data from the kernel
>rodata segment. Instead, use strncpy() which will fill the trailing bytes
>with zeros.
>
>This was found with the future CONFIG_FORTIFY_SOURCE feature.
>
>Cc: Daniel Micay <danielmicay@gmail.com>
>Signed-off-by: Kees Cook <keescook@chromium.org>
>Signed-off-by: David S. Miller <davem@davemloft.net>

Queued for 4.9 and 4.4, thank you.

--
Thanks,
Sasha

Re: [PATCH] bna: ethtool: Avoid reading past end of buffer

[David Miller]

From: Kees Cook <keescook@chromium.org>
Date: Fri, 5 May 2017 15:30:23 -0700

> Using memcpy() from a string that is shorter than the length copied means
> the destination buffer is being filled with arbitrary data from the kernel
> rodata segment. Instead, use strncpy() which will fill the trailing bytes
> with zeros.
> 
> This was found with the future CONFIG_FORTIFY_SOURCE feature.
> 
> Cc: Daniel Micay <danielmicay@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Applied.

[PATCH] bna: ethtool: Avoid reading past end of buffer

[Kees Cook]

Using memcpy() from a string that is shorter than the length copied means
the destination buffer is being filled with arbitrary data from the kernel
rodata segment. Instead, use strncpy() which will fill the trailing bytes
with zeros.

This was found with the future CONFIG_FORTIFY_SOURCE feature.

Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/ethernet/brocade/bna/bnad_ethtool.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/brocade/bna/bnad_ethtool.c b/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
index 286593922139..31032de5843b 100644
--- a/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
+++ b/drivers/net/ethernet/brocade/bna/bnad_ethtool.c
@@ -547,8 +547,8 @@ bnad_get_strings(struct net_device *netdev, u32 stringset, u8 *string)
 		for (i = 0; i < BNAD_ETHTOOL_STATS_NUM; i++) {
 			BUG_ON(!(strlen(bnad_net_stats_strings[i]) <
 				   ETH_GSTRING_LEN));
-			memcpy(string, bnad_net_stats_strings[i],
-			       ETH_GSTRING_LEN);
+			strncpy(string, bnad_net_stats_strings[i],
+				ETH_GSTRING_LEN);
 			string += ETH_GSTRING_LEN;
 		}
 		bmap = bna_tx_rid_mask(&bnad->bna);
-- 
2.7.4


-- 
Kees Cook
Pixel Security