linux-kernel - Re: [PATCH v2 1/3] x86/uprobes: Fix not using prefixes.nbytes for loop over prefixes.bytes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20201203170140.GM3059@zn.tnic>
Date:   Thu, 3 Dec 2020 18:01:40 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Tom Lendacky <thomas.lendacky@....com>
Cc:     Masami Hiramatsu <mhiramat@...nel.org>, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        "H . Peter Anvin" <hpa@...or.com>, Joerg Roedel <jroedel@...e.de>,
        "Gustavo A . R . Silva" <gustavoars@...nel.org>,
        Jann Horn <jannh@...gle.com>,
        Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
        Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/3] x86/uprobes: Fix not using prefixes.nbytes for
 loop over prefixes.bytes

On Thu, Dec 03, 2020 at 05:54:20PM +0100, Borislav Petkov wrote:
> On Thu, Dec 03, 2020 at 10:45:48AM -0600, Tom Lendacky wrote:
> > Since this is based on the array size, can
> > 
> > 	idx < NUM_LEGACY_PREFIXES
> > 
> > be replaced with:
> > 
> > 	idx < ARRAY_SIZE(insn->prefixes.bytes)
> 
> Actually, this needs another change:
> 
> struct insn_field {
>         union {
>                 insn_value_t value;
>                 insn_byte_t bytes[NUM_LEGACY_PREFIXES];

Blergh, spoke too soon. All those struct insn members are struct
insn_field.

insn.prefixes should probably be a separate array of explicit size
NUM_LEGACY_PREFIXES, not that insn_byte_t bytes[] gets enlarged in the
future for whatever reason, while the max legacy prefixes count will
remain 4.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette