Patch "wifi: airo: do not assign -1 to unsigned char" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wifi: airo: do not assign -1 to unsigned char

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wifi-airo-do-not-assign-1-to-unsigned-char.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b0a0ea58e25de08c51f3afb1497ded9f0477a49e
Author: Jason A. Donenfeld <Jason@xxxxxxxxx>
Date:   Mon Oct 24 18:28:43 2022 +0200

    wifi: airo: do not assign -1 to unsigned char
    
    [ Upstream commit e6cb8769452e8236b52134e5cb4a18b8f5986932 ]
    
    With char becoming unsigned by default, and with `char` alone being
    ambiguous and based on architecture, we get a warning when assigning the
    unchecked output of hex_to_bin() to that unsigned char. Mark `key` as a
    `u8`, which matches the struct's type, and then check each call to
    hex_to_bin() before casting.
    
    Cc: Kalle Valo <kvalo@xxxxxxxxxx>
    Cc: linux-wireless@xxxxxxxxxxxxxxx
    Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
    Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221024162843.535921-1-Jason@xxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/cisco/airo.c b/drivers/net/wireless/cisco/airo.c
index 0569f37e9ed5..8c9c6bfbaeee 100644
--- a/drivers/net/wireless/cisco/airo.c
+++ b/drivers/net/wireless/cisco/airo.c
@@ -5236,7 +5236,7 @@ static int get_wep_tx_idx(struct airo_info *ai)
 	return -1;
 }
 
-static int set_wep_key(struct airo_info *ai, u16 index, const char *key,
+static int set_wep_key(struct airo_info *ai, u16 index, const u8 *key,
 		       u16 keylen, int perm, int lock)
 {
 	static const unsigned char macaddr[ETH_ALEN] = { 0x01, 0, 0, 0, 0, 0 };
@@ -5287,7 +5287,7 @@ static void proc_wepkey_on_close(struct inode *inode, struct file *file)
 	struct net_device *dev = PDE_DATA(inode);
 	struct airo_info *ai = dev->ml_priv;
 	int i, rc;
-	char key[16];
+	u8 key[16];
 	u16 index = 0;
 	int j = 0;
 
@@ -5315,12 +5315,22 @@ static void proc_wepkey_on_close(struct inode *inode, struct file *file)
 	}
 
 	for (i = 0; i < 16*3 && data->wbuffer[i+j]; i++) {
+		int val;
+
+		if (i % 3 == 2)
+			continue;
+
+		val = hex_to_bin(data->wbuffer[i+j]);
+		if (val < 0) {
+			airo_print_err(ai->dev->name, "WebKey passed invalid key hex");
+			return;
+		}
 		switch(i%3) {
 		case 0:
-			key[i/3] = hex_to_bin(data->wbuffer[i+j])<<4;
+			key[i/3] = (u8)val << 4;
 			break;
 		case 1:
-			key[i/3] |= hex_to_bin(data->wbuffer[i+j]);
+			key[i/3] |= (u8)val;
 			break;
 		}
 	}