CVE-2026-63797

In the Linux kernel, the following vulnerability has been resolved:

rpmsg: char: Fix use-after-free on probe error path

rpmsgchrdevprobe() stores the newly allocated eptdev in the default endpoint's priv pointer before calling rpmsgchrdeveptdevadd(). If rpmsgchrdeveptdevadd() then fails, its error path frees eptdev while the default endpoint may still dispatch callbacks with the stale priv pointer.

Avoid publishing eptdev through the default endpoint until rpmsgchrdeveptdevadd() succeeds. Messages received before the priv pointer is published should be ignored by rpmsgeptcb(). Flow-control updates can hit rpmsgeptflowcb() in the same window, so make both callbacks return success when priv is NULL.