In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read in rtw_restruct_wmm_ie() rtw_restruct_wmm_ie() scans in_ie for a WMM IE with: while (i < in_len) { ... if (i + 5 < in_len && in_…

Overview

In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix OOB read in rtw_restruct_wmm_ie()

rtw_restruct_wmm_ie() scans in_ie for a WMM IE with:

while (i < in_len) {
	...
	if (i + 5 < in_len && in_ie[i] == 0xDD && ...) {
		...
		break;
	}
	i += (in_ie[i + 1] + 2); /* to the next IE element */
}

When the "i + 5 < in_len" match check fails simply because i is within 5 bytes of the end of the buffer (i.e. no WMM IE was found near the tail of in_ie), execution falls through to "i += (in_ie[i + 1] + 2)", which reads in_ie[i + 1]. If i == in_len

• 1 at that point, this is a 1-byte out-of-bounds read of an attacker-influenced IE buffer built from association/scan data.

Commit a75281626fc8f ("staging: rtl8723bs: fix potential out-of-bounds read in rtw_restruct_wmm_ie") added the "i + 5 < in_len" guard to the match condition itself, but did not add an equivalent guard before the fallthrough advance, so the same class of OOB read remained reachable through the non-matching path.

Add an explicit bounds check before advancing to the next IE.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.