CVE-2026-90251

CVE CVE-2026-90251EUVD EUVD-2026-81844Veröffentlicht 2026-09-17T16:07:52.000Z

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MSFT: validate evt_prefix_len against the response length read_supported_features() only checks that the response covers the fixed part of struct msft_rp_read_supported_features, which is 11 bytes: if (skb->len < sizeof(*rp)) { bt_dev_err(hdev, "MSFT supported features length mismatch"); goto failed; } evt_prefix[] is a flexible array member and rp->evt_prefix_len is an unvalidated u8 taken straight out of that response, so msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len, GFP_KERNEL); copies up to 255 bytes from a reply that may have carried none of them. What is copied is data the controller never sent, and it is then used to match incoming vendor events in msft_vendor_evt(). This is not an out-of-bounds access. An skb data allocation always has at least SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) bytes past the payload, which is more than the 255 byte maximum, so the read stays inside the allocation and KASAN does not report it. It is still a read of bytes the host was never given, with the length fully controlled by the controller. Reject a response that is too short for the prefix it declares. Verified with an emulated controller over /dev/vhci on a KASAN kernel, with vhci made to advertise an MSFT opcode the way btintel, btqca, btmtk and btrtl do unconditionally. A reply of exactly 11 bytes declaring evt_prefix_len = 255 reaches kmemdup and copies 255 bytes ("skb->len=11 evt_prefix_len=255", with the copied buffer dumped); since the reply ends at the fixed part, all 255 come from past the end of the response. No KASAN report is produced, as expected from the allocation slack described above. With this patch the response is rejected with "MSFT event prefix length mismatch" and msft->evt_prefix is left unset.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <620c2631cff490d14d0b9d56f185cc745806d6d7; patch: 7.2.6; patch: 6.6.157; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <dce783a10e70f013410f5b583a29fc3286899629; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <21f539c59ed330b671d75fd119c5f659ff92fbd1; patch: 6.1.188; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <0079e1a944634ab2dc1c7cdec1144486d096407e; patch: 6.18.52; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <63562cfaea8a650fdb31ee8de21c32e3600be642; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <52b1b3b4d403cbda1b70ce2385e1a71f166a87ba; 5.8; patch: 0; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <7c2658023d839b651368a5b8b781bf9a817647cb; patch: 7.3-rc1; 145373cb1b1fcdba2059e945d0aa2613af2e84d1 <e804d54a5a99d99250490e68093eff7190472e6f; patch: 6.12.110; patch: 5.10.270; patch: 5.15.221

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.