staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()

Summary

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr() rtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from a wireless management frame. For each candidate attribute it only checks that the fixed 4-byte attribute header (2-byte ID + 2-byte length) fits inside the IE: if (attr_ptr + 4 > wps_ie + wps_ielen) break; u16 attr_id = get_unaligned_be16(attr_ptr); u16 attr_data_len = get_unaligned_be16(attr_ptr + 2); u16 attr_len = attr_data_len + 4; attr_data_len (and therefore attr_len) is read directly from the wire and is never checked against the remaining bytes in the IE before being used as the size of: memcpy(buf_attr, attr_ptr, attr_len); Since attr_len is fully attacker controlled (0 to 65535+4), this is both a heap OOB read of wps_ie, and, more seriously, a stack buffer overflow at several call sites where buf_attr is a single-byte stack variable, e.g. rtw_get_wps_attr_content()'s callers passing WPS_ATTR_SELECTED_REGISTRAR into a stack "u8 sr"/"u8 selected_registrar" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c, drivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a beacon or probe response processed during scanning can therefore smash the stack of the parsing thread. rtw_get_wps_attr_content() itself has no independent length check and simply trusts the attr_len it gets back from rtw_get_wps_attr(), so fixing the bound here also fixes that caller. The "attr_ptr + 4 > wps_ie + wps_ielen" header check above was added by commit 1463ca3ec6601 ("staging: rtl8723bs: fix OOB reads in rtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()"), which bounded the fixed header but never extended the check to cover the variable-length attribute data that follows it. Add that missing check before attr_len is used as a memcpy() length or accepted as a match.

Timeline

1. Sep 16, 2026, 10:33 AM UTCCVE published
2. Oct 19, 2026, 8:56 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in 931640dfcb8cfa08f6cfb46229716d8072356420; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in 3a6457ebf39080b87c712657fdb38f34a24fc3ff; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in fd5e24ea8373347d0352f153a66e8647337d1b10; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in a53d1ac9ce63db07943b2b2248111003851fb00f; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in ff61aa3289355dafa811550a1764691cd1f5d33b; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in 34f51d196c43a42046d229de5e79025d5ca553ca; From 554c0a3abf216c991c5ebddcdb2c08689ecd290b · fixed in 99aa998dec83ba180822f70e6d48a514fc81c20d

• Linux Linux

  4.12

• KernelLinux

  From 4.12.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 7