CVE-2026-31532can: raw: fix ro->uniq use-after-free in raw_rcv()

Official description

In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. [mkl: applied manually]

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/1de30576a6dfeaaa27ef91fa272e6b9240b6fbd3
• https://git.kernel.org/stable/c/64c8553decf5a5f2417bd54761ea0a832c56c4ca
• https://git.kernel.org/stable/c/3f43f12fde34737fba091b7e3ab391e14ddbb0be
• https://git.kernel.org/stable/c/5e9cfffad898bbeaafd0ea608a6d267362f050fc
• https://git.kernel.org/stable/c/572f0bf536ebc14f6e7da3d21a85cf076de8358e
• https://git.kernel.org/stable/c/1a0f2de81f7fbdc538fc72d7d74609b79bc83cc0
• https://git.kernel.org/stable/c/7201a531b9a5ed892bfda5ded9194ef622de8ffa
• https://git.kernel.org/stable/c/34c1741254ff972e8375faf176678a248826fe3a
• https://git.kernel.org/stable/c/a535a9217ca3f2fccedaafb2fddb4c48f27d36dc
• https://cert-portal.siemens.com/productcert/html/ssa-784472.html