AZL-103928
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-103928.json
- JSON Data
- https://api.osv.dev/v1/vulns/AZL-103928
- Upstream
- Published
- 2026-09-24T17:17:10Z
- Modified
- 2026-09-25T14:16:08Z
- Summary
- CVE-2026-93783 affecting package kernel 6.6.157.1-1
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: validate skb length in rfcomm_recv_frame
rfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences hdr->addr and hdr->ctrl without validating skb->len first. A truncated frame with skb->len less than the minimum header size causes an out-of-bounds read of uninitialized memory. Additionally, a zero-length frame causes skb->len-- to underflow to UINT_MAX, making skb_tail_pointer() read far past the buffer.
Commit 23882b828c3c ("Bluetooth: RFCOMM: validate skb length in MCC handlers") fixed the same class of missing-length-check bugs in the MCC sub-handlers, but the top-level rfcomm_recv_frame() was left unfixed. KMSAN reports:
BUG: KMSAN: uninit-value in rfcomm_run ... Uninit was created at: __alloc_skb+0x474/0xb60 vhci_write+0xe9/0x870
Fix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1 (the minimum frame must have a 3-byte header and a 1-byte FCS).
- References