From 260a9ad9446723d4063ed802989758852809714d Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 14 Apr 2021 11:29:55 +0300
Subject: [PATCH] ipw2x00: potential buffer overflow in libipw_wx_set_encodeext()
Git-commit: 260a9ad9446723d4063ed802989758852809714d
Patch-mainline: v5.13-rc1
References: git-fixes

The "ext->key_len" is a u16 that comes from the user.  If it's over
SCM_KEY_LEN (32) that could lead to memory corruption.

Fixes: e0d369d1d969 ("[PATCH] ieee82011: Added WE-18 support to default wireless extension handler")
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stanislav Yakovlev <stas.yakovlev@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/YHaoA1i+8uT4ir4h@mwanda
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/intel/ipw2x00/libipw_wx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_wx.c b/drivers/net/wireless/intel/ipw2x00/libipw_wx.c
index a0cf78c418ac..903de34028ef 100644
--- a/drivers/net/wireless/intel/ipw2x00/libipw_wx.c
+++ b/drivers/net/wireless/intel/ipw2x00/libipw_wx.c
@@ -633,8 +633,10 @@ int libipw_wx_set_encodeext(struct libipw_device *ieee,
 	}
 
 	if (ext->alg != IW_ENCODE_ALG_NONE) {
-		memcpy(sec.keys[idx], ext->key, ext->key_len);
-		sec.key_sizes[idx] = ext->key_len;
+		int key_len = clamp_val(ext->key_len, 0, SCM_KEY_LEN);
+
+		memcpy(sec.keys[idx], ext->key, key_len);
+		sec.key_sizes[idx] = key_len;
 		sec.flags |= (1 << idx);
 		if (ext->alg == IW_ENCODE_ALG_WEP) {
 			sec.encode_alg[idx] = SEC_ALG_WEP;
-- 
2.26.2