Re: [PATCH] libertas: Avoid reading past end of buffer
From: Joe Perches <joe@perches.com>
Date: 2017-05-10 04:33:26
Also in:
linux-wireless, lkml
Subsystem:
marvell libertas wireless driver, the rest · Maintainer:
Linus Torvalds
On Tue, 2017-05-09 at 16:23 -0700, Kees Cook wrote:
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. Additionally adjust indentation to keep checkpatch.pl happy. This was found with the future CONFIG_FORTIFY_SOURCE feature.
[]
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/wireless/marvell/libertas/mesh.c b/drivers/net/wireless/marvell/libertas/mesh.c
[]
quoted hunk ↗ jump to hunk
@@ -1177,9 +1177,9 @@ void lbs_mesh_ethtool_get_strings(struct net_device *dev, switch (stringset) { case ETH_SS_STATS: for (i = 0; i < MESH_STATS_NUM; i++) { - memcpy(s + i * ETH_GSTRING_LEN, - mesh_stat_strings[i], - ETH_GSTRING_LEN); + strncpy(s + i * ETH_GSTRING_LEN, + mesh_stat_strings[i], + ETH_GSTRING_LEN); }
The better solution is to declare mesh_stat_strings in in the normal way --- drivers/net/wireless/marvell/libertas/mesh.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/marvell/libertas/mesh.c b/drivers/net/wireless/marvell/libertas/mesh.c
index d0c881dd5846..a535e7f48d2d 100644
--- a/drivers/net/wireless/marvell/libertas/mesh.c
+++ b/drivers/net/wireless/marvell/libertas/mesh.c@@ -1108,15 +1108,15 @@ void lbs_mesh_set_txpd(struct lbs_private *priv, * Ethtool related */ -static const char * const mesh_stat_strings[] = { - "drop_duplicate_bcast", - "drop_ttl_zero", - "drop_no_fwd_route", - "drop_no_buffers", - "fwded_unicast_cnt", - "fwded_bcast_cnt", - "drop_blind_table", - "tx_failed_cnt" +static const char mesh_stat_strings[][ETH_GSTRING_LEN] = { + "drop_duplicate_bcast", + "drop_ttl_zero", + "drop_no_fwd_route", + "drop_no_buffers", + "fwded_unicast_cnt", + "fwded_bcast_cnt", + "drop_blind_table", + "tx_failed_cnt", }; void lbs_mesh_ethtool_get_stats(struct net_device *dev,