Messages in this thread | | | Date | Mon, 30 Apr 2018 11:05:42 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v5 6/6] x86/microcode/AMD: Check the equivalence table size when scanning it |
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On Mon, Apr 23, 2018 at 11:34:11PM +0200, Maciej S. Szmigiero wrote: > Currently, the code scanning the CPU equivalence table read from a > microcode container file assumes that it actually contains a terminating > zero entry. > Let's check also the size of this table to make sure that we don't read > past it in case it actually doesn't.
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> @@ -697,6 +706,7 @@ static unsigned int install_equiv_cpu_table(const u8 *buf, size_t buf_size) > } > > memcpy(equiv_cpu_table, buf + CONTAINER_HDR_SZ, equiv_tbl_len); > + equiv_cpu_table_entries = equiv_tbl_len / sizeof(struct equiv_cpu_entry); > > return equiv_tbl_len;
Instead of adding yet another global var which needs handling too, and touching so many places, just do all checks and preparations in install_equiv_cpu_table() so that the rest of the code can get what it expects: terminating zero entry and proper size.
Thx.
-- Regards/Gruss, Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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