staging: rtl8723bs: fix out-of-bounds read in rtw_get_ie() parser

The Information Element (IE) parser rtw_get_ie() trusted the length
byte of each IE without validating that the IE body (len bytes after
the 2-byte header) fits inside the remaining frame buffer. A malformed
frame can advertise an IE length larger than the available data, causing
the parser to increment its pointer beyond the buffer end. This results
in out-of-bounds reads or, depending on the pattern, an infinite loop.

Fix by validating that (offset + 2 + len) does not exceed the limit
before accepting the IE or advancing to the next element.

This prevents OOB reads and ensures the parser terminates safely on
malformed frames.

Signed-off-by: Navaneeth K <knavaneeth786@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Navaneeth K
2025-11-20 16:23:52 +00:00
committed by Greg Kroah-Hartman
parent 1520007aa3
commit 154828bf95

View File

@@ -138,22 +138,24 @@ u8 *rtw_get_ie(u8 *pbuf, signed int index, signed int *len, signed int limit)
signed int tmp, i;
u8 *p;
if (limit < 1)
if (limit < 2)
return NULL;
p = pbuf;
i = 0;
*len = 0;
while (1) {
while (i + 2 <= limit) {
tmp = *(p + 1);
if (i + 2 + tmp > limit)
break;
if (*p == index) {
*len = *(p + 1);
*len = tmp;
return p;
}
tmp = *(p + 1);
p += (tmp + 2);
i += (tmp + 2);
if (i >= limit)
break;
}
return NULL;
}