mwifiex: Fix possible buffer overflows in mwifiex_cmd_append_vsie_tlv()

[ Upstream commit b70261a288ea4d2f4ac7cd04be08a9f0f2de4f4d ]

mwifiex_cmd_append_vsie_tlv() calls memcpy() without checking
the destination size may trigger a buffer overflower,
which a local user could use to cause denial of service
or the execution of arbitrary code.
Fix it by putting the length check before calling memcpy().

Signed-off-by: Qing Xu <m1s5p6688@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index 39b78dc..e7c8972 100644 (file)
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -2568,6 +2568,13 @@ mwifiex_cmd_append_vsie_tlv(struct mwifiex_private *priv,
                        vs_param_set->header.len =
                                cpu_to_le16((((u16) priv->vs_ie[id].ie[1])
                                & 0x00FF) + 2);
+                       if (le16_to_cpu(vs_param_set->header.len) >
+                               MWIFIEX_MAX_VSIE_LEN) {
+                               mwifiex_dbg(priv->adapter, ERROR,
+                                           "Invalid param length!\n");
+                               break;
+                       }
+
                        memcpy(vs_param_set->ie, priv->vs_ie[id].ie,
                               le16_to_cpu(vs_param_set->header.len));
                        *buffer += le16_to_cpu(vs_param_set->header.len) +