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Date:   Wed, 14 Apr 2021 11:29:55 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Stanislav Yakovlev <stas.yakovlev@gmail.com>
Cc:     Kalle Valo <kvalo@codeaurora.org>,
        James Ketrenos <jketreno@linux.intel.com>,
        Jeff Garzik <jgarzik@pobox.com>,
        linux-wireless@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH v2] ipw2x00: potential buffer overflow in
 libipw_wx_set_encodeext()
Message-ID: <YHaoA1i+8uT4ir4h@mwanda>
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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")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: use clamp_val() instead of min_t()

 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;
-- 
2.30.2