HIGH Introduced in 4.12
rtl8723bs WmmIE OOB
CVE-2026-90016
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
KernelScan AI4.3MEDIUM
01Description
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.
02KernelScan AI Analysis
Risk summary
A 1-byte out-of-bounds read in the rtl8723bs WiFi driver's Information Element parser can be triggered by a nearby attacker sending crafted WiFi frames with malformed IEs. The bug affects devices using the Realtek RTL8723BS SDIO WiFi chip, common on Atom and ARM boards. Impact is limited to a small information leak with no integrity or availability impact.
Vulnerability analysis
The WiFi driver's Information Element parser scans received frame data for WMM IEs but fails to check that enough bytes remain before reading the length field used to advance to the next element. When the scan position reaches the last byte of the buffer without finding a match, the code reads one byte past the end of the buffer. The fix adds an explicit bounds check before the advance, breaking out of the loop when fewer than two bytes remain. The vulnerable code path processes WiFi association and scan response data, so an attacker within wireless range of a device using this specific Realtek SDIO WiFi chip can trigger the out-of-bounds read by sending crafted WiFi frames with malformed Information Elements.
Lifecycle
03Fix Versions
| Branch | Introduced | Fixed in | Patch commit |
|---|---|---|---|
| 6.12 | 4.12 | 6.12.112 | e63b72c5d733 |
| 6.18 | 4.12 | 6.18.52 | 4420cc71841b |
| 6.6 | 4.12 | 6.6.160 | 716850842d2f |
| 7.2 | 4.12 | 7.2.5 | fd19b8895f8a |
| mainline | 4.12 | 7.3 | 28a289beaf22 |
| cip/6.12 | 4.12 | 6.12.112-cip33 | e63b72c5d733 |
04CIP Kernels
State of the newest release of each Civil Infrastructure Platform SLTS tree, from CIP's own fix records.
| CIP tree | State |
|---|---|
| cip/6.12 | Fixed in 6.12.112-cip33 |
| cip/6.1 | Affected — no CIP fix yet (latest 6.1.189-cip61) |
| cip/6.1-rt | Affected — no CIP fix yet (latest 6.1.189-cip61-rt32) |
| cip/5.10 | Affected — no CIP fix yet (latest 5.10.271-cip78) |
| cip/5.10-rt | Affected — no CIP fix yet (latest 5.10.268-cip77-rt34) |
| cip/4.19 | Affected — no CIP fix yet (latest 4.19.325-cip136) |
| cip/4.19-rt | Affected — no CIP fix yet (latest 4.19.325-cip136-rt50) |