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authorSzymon Heidrich <szymon.heidrich@gmail.com>2023-01-03 10:17:09 +0100
committerDavid S. Miller <davem@davemloft.net>2023-01-03 09:24:41 +0000
commitc7dd13805f8b8fc1ce3b6d40f6aff47e66b72ad2 (patch)
treea262f5859ecf01608d6af5f44328bbe3f2b35a72
parent7dc61838541928895abae6d2355258e02a251bba (diff)
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usb: rndis_host: Secure rndis_query check against int overflow
Variables off and len typed as uint32 in rndis_query function are controlled by incoming RNDIS response message thus their value may be manipulated. Setting off to a unexpectetly large value will cause the sum with len and 8 to overflow and pass the implemented validation step. Consequently the response pointer will be referring to a location past the expected buffer boundaries allowing information leakage e.g. via RNDIS_OID_802_3_PERMANENT_ADDRESS OID. Fixes: ddda08624013 ("USB: rndis_host, various cleanups") Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/usb/rndis_host.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c
index f79333fe1783..7b3739b29c8f 100644
--- a/drivers/net/usb/rndis_host.c
+++ b/drivers/net/usb/rndis_host.c
@@ -255,7 +255,8 @@ static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
off = le32_to_cpu(u.get_c->offset);
len = le32_to_cpu(u.get_c->len);
- if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
+ if (unlikely((off > CONTROL_BUFFER_SIZE - 8) ||
+ (len > CONTROL_BUFFER_SIZE - 8 - off)))
goto response_error;
if (*reply_len != -1 && len != *reply_len)