Bug 2424858 (CVE-2025-68362)

Summary: CVE-2025-68362 kernel: wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187_rx_cb()
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: rhel-process-autobot, watson-tool-maintainers
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-12-24 11:01:30 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: rtl818x: rtl8187: Fix potential buffer underflow in rtl8187_rx_cb()

The rtl8187_rx_cb() calculates the rx descriptor header address
by subtracting its size from the skb tail pointer.
However, it does not validate if the received packet
(skb->len from urb->actual_length) is large enough to contain this
header.

If a truncated packet is received, this will lead to a buffer
underflow, reading memory before the start of the skb data area,
and causing a kernel panic.

Add length checks for both rtl8187 and rtl8187b descriptor headers
before attempting to access them, dropping the packet cleanly if the
check fails.
Comment 1 Vipul Nair 2025-12-24 13:05:55 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122458-CVE-2025-68362-e4d6@gregkh/T