[PATCH AUTOSEL 6.0 07/44] wifi: airo: do not assign -1 to unsigned char

From: Sasha Levin
Date: Fri Nov 18 2022 - 21:12:24 EST


From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>

[ 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>
---
drivers/net/wireless/cisco/airo.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/cisco/airo.c b/drivers/net/wireless/cisco/airo.c
index 10daef81c355..fb2c35bd73bb 100644
--- a/drivers/net/wireless/cisco/airo.c
+++ b/drivers/net/wireless/cisco/airo.c
@@ -5232,7 +5232,7 @@ 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 };
@@ -5283,7 +5283,7 @@ 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;

@@ -5311,12 +5311,22 @@ 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;
}
}
--
2.35.1