Bug 2559772 (CVE-2026-99010)

Summary: CVE-2026-99010 kernel: Bluetooth: RFCOMM: free the skb when the DLC has no owner
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's Bluetooth Radio Frequency Communication (RFCOMM) subsystem. When a communication socket is closed while the underlying connection session remains active, incoming data packets are not released from memory. A remote attacker can exploit this vulnerability by continuously transmitting data during socket teardown, causing an unbounded memory leak that results in kernel resource exhaustion and a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-23 13:34:18 UTC
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: free the skb when the DLC has no owner

rfcomm_recv_data() hands the skb to d->data_ready() and returns 0
without freeing it, so the callback owns the skb from that point on.
The tty implementation frees it when the DLC has been detached from its
device:

  static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc,
                                    struct sk_buff *skb)
  {
          struct rfcomm_dev *dev = dlc->owner;

          if (!dev) {
                  kfree_skb(skb);
                  return;
          }

The socket implementation returns without freeing it, and the skb is
leaked.

A connected DLC can have no owner: rfcomm_sock_destruct() clears
d->owner, while the DLC itself stays on the session until it is closed.
Data frames that arrive in that window still find d->state ==
BT_CONNECTED in rfcomm_recv_data() and are handed to the callback, one
leaked skb each.

The leak does not stop on its own either.  The remote runs out of
credits only once RFCOMM_RX_THROTTLED is set, and for a socket the only
place that sets it is rfcomm_sk_data_ready() itself, below the return.
rfcomm_process_dlcs() keeps granting credits, so the remote keeps
sending and the leak keeps growing.

Free the skb, as the tty side does.