CVE-2026-53255Bluetooth: MGMT: validate advertising TLV before type checks

Official description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: validate advertising TLV before type checks tlv_data_is_valid() reads each advertising data field length from data[i], then inspects data[i + 1] for managed EIR types before checking that the current field still fits inside the supplied buffer. A malformed field whose length byte is the last byte of the buffer can therefore make the parser read one byte past the advertising data. KASAN reported the following when a malformed MGMT_OP_ADD_ADVERTISING request reached that path: BUG: KASAN: vmalloc-out-of-bounds in tlv_data_is_valid() Read of size 1 Call trace: tlv_data_is_valid() add_advertising() hci_mgmt_cmd() hci_sock_sendmsg() Move the existing element-length check before any type-octet inspection so each non-empty element is proven to contain its type byte before the parser looks at data[i + 1].

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/13ad995071a06570668dd8daab3616c247c72080
• https://git.kernel.org/stable/c/06fcbd79c3c360a50f9be9d370769bbd738d0976
• https://git.kernel.org/stable/c/f7093ac233c1e7f51d125534f46067772a113175
• https://git.kernel.org/stable/c/74c08e4db35a476c3462aeb65846f955be732626
• https://git.kernel.org/stable/c/18fea1cb0c2599752e908c8217490f73ddd33e00
• https://git.kernel.org/stable/c/1a3c8ffbb469859b076445af44bdfa6a711d483e
• https://git.kernel.org/stable/c/2a3f3ed9e198ae23c15859ace2f9ca6cfdc35b57
• https://git.kernel.org/stable/c/de23fb62259aa01d294f77238ae3b835eb674413
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html