Bug 2502226 (CVE-2026-63797)

Summary: CVE-2026-63797 kernel: rpmsg: char: Fix use-after-free on probe error path
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's rpmsg character device. This vulnerability, a use-after-free, occurs during the probe process when an internal pointer to a device endpoint (eptdev) is prematurely stored. If an error occurs during the device's addition, the eptdev memory is freed, but the system may still attempt to access this freed memory. This could lead to system instability or potentially allow an attacker to execute arbitrary code.
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Description OSIDB Bzimport 2026-07-19 13:02:49 UTC 
In the Linux kernel, the following vulnerability has been resolved:

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

rpmsg_chrdev_probe() stores the newly allocated eptdev in the default
endpoint's priv pointer before calling rpmsg_chrdev_eptdev_add(). If
rpmsg_chrdev_eptdev_add() 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
rpmsg_chrdev_eptdev_add() succeeds. Messages received before the priv
pointer is published should be ignored by rpmsg_ept_cb(). Flow-control
updates can hit rpmsg_ept_flow_cb() in the same window, so make both
callbacks return success when priv is NULL.
Comment 1 Keith Grant 2026-07-20 14:47:39 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071900-CVE-2026-63797-44ec@gregkh/T