Bug 2420277 (CVE-2023-53817)

Summary: CVE-2023-53817 kernel: crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-12-09 01:05:20 UTC 
In the Linux kernel, the following vulnerability has been resolved:

crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui()

During NVMeTCP Authentication a controller can trigger a kernel
oops by specifying the 8192 bit Diffie Hellman group and passing
a correctly sized, but zeroed Diffie Hellamn value.
mpi_cmp_ui() was detecting this if the second parameter was 0,
but 1 is passed from dh_is_pubkey_valid(). This causes the null
pointer u->d to be dereferenced towards the end of mpi_cmp_ui()
Comment 1 Alexander B 2025-12-10 05:01:05 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120945-CVE-2023-53817-49a5@gregkh/T