Bug 2298195 (CVE-2022-48854)

Summary: CVE-2022-48854 kernel: net: arc_emac: Fix use after free in arc_mdio_probe()
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: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: kernel 5.16.15, kernel 5.17 Doc Type: If docs needed, set a value
Doc Text:
A vulnerability was found in the Linux kernel's ARC EMAC driver, where a use-after-free occurs in the arc_mdio_probe() function, when the bus state is MDIOBUS_ALLOCATED, calling mdiobus_free(bus) deallocates the bus while its name is still accessed, leading to potential memory corruption.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2024-07-16 13:25:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net: arc_emac: Fix use after free in arc_mdio_probe()

If bus->state is equal to MDIOBUS_ALLOCATED, mdiobus_free(bus) will free
the "bus". But bus->name is still used in the next line, which will lead
to a use after free.

We can fix it by putting the name in a local variable and make the
bus->name point to the rodata section "name",then use the name in the
error message without referring to bus to avoid the uaf.