Bug 2395803 (CVE-2025-39810)

Summary: CVE-2025-39810 kernel: bnxt_en: Fix memory corruption when FW resources change during ifdown
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-09-16 14:03:34 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bnxt_en: Fix memory corruption when FW resources change during ifdown

bnxt_set_dflt_rings() assumes that it is always called before any TC has
been created.  So it doesn't take bp->num_tc into account and assumes
that it is always 0 or 1.

In the FW resource or capability change scenario, the FW will return
flags in bnxt_hwrm_if_change() that will cause the driver to
reinitialize and call bnxt_cancel_reservations().  This will lead to
bnxt_init_dflt_ring_mode() calling bnxt_set_dflt_rings() and bp->num_tc
may be greater than 1.  This will cause bp->tx_ring[] to be sized too
small and cause memory corruption in bnxt_alloc_cp_rings().

Fix it by properly scaling the TX rings by bp->num_tc in the code
paths mentioned above.  Add 2 helper functions to determine
bp->tx_nr_rings and bp->tx_nr_rings_per_tc.
Comment 1 Keith Grant 2025-09-16 15:26:15 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025091614-CVE-2025-39810-ed5c@gregkh/T