Messages in this thread | | | Date | Mon, 7 Aug 2023 22:57:46 +0200 | From | Borislav Petkov <> | Subject | Re: potential null pointer dereference in setup_cpuid_table |
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On Thu, Jul 27, 2023 at 03:22:42PM +0100, Colin King (gmail) wrote: > Hi, > > Static analysis with cppcheck found a potential null pointer dereference in > function setup_cpuid_table in arch/x86/kernel/sev-shared.c as follows: > > if (!cc_info || !cc_info->cpuid_phys || cc_info->cpuid_len < > PAGE_SIZE) > sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID); > > cpuid_table_fw = (const struct snp_cpuid_table > *)cc_info->cpuid_phys; > > > cc_info is being null checked, so it's potentially null,
You mean, it is not null if the check passes?
> however, the assignment to cpuid_table_fw is dereferencing cc_info. > Either cc_info is never null and the null check is redundant, or there > is a potential null pointer dereference.
I'm not sure what you're asking. It is checked for !NULL in the if clause.
Or are you missing the fact that sev_es_terminate() actually terminates the guest so that if it is NULL, it won't ever be dereferenced?
Or am I missing something?
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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