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
| ||
|
Message-ID: <202209271423.EA345AD@keescook> Date: Tue, 27 Sep 2022 14:23:59 -0700 From: Kees Cook <keescook@...omium.org> To: Wei Liu <wei.liu@...nel.org> Cc: "K. Y. Srinivasan" <kys@...rosoft.com>, "Gustavo A. R. Silva" <gustavoars@...nel.org>, Haiyang Zhang <haiyangz@...rosoft.com>, Stephen Hemminger <sthemmin@...rosoft.com>, Dexuan Cui <decui@...rosoft.com>, linux-hyperv@...r.kernel.org, Nathan Chancellor <nathan@...nel.org>, linux-kernel@...r.kernel.org, linux-hardening@...r.kernel.org Subject: Re: [PATCH] Drivers: hv: vmbus: Split memcpy of flex-array On Sat, Sep 24, 2022 at 10:34:12AM +0000, Wei Liu wrote: > Hi Kees > > On Fri, Sep 23, 2022 at 09:22:55PM -0700, Kees Cook wrote: > > On Fri, Sep 23, 2022 at 10:42:38PM -0500, Gustavo A. R. Silva wrote: > > > On Fri, Sep 23, 2022 at 08:07:41PM -0700, Kees Cook wrote: > > > > To work around a misbehavior of the compiler's ability to see into > > > > composite flexible array structs (as detailed in the coming memcpy() > > > > hardening series[1]), split the memcpy() of the header and the payload > > > > so no false positive run-time overflow warning will be generated. As it > > > > turns out, this appears to actually reduce the text size: > > > > Er, actually, I can't read/math. ;) It _does_ grow the text size. (That's > > 2_3_ not 22 at the start of the text size...) On examination, it appears > > to unroll the already inlined memcpy further. > > Can you provide an updated commit message? No need to resend. Since I got more testing from Nathan (and the original warning message), I figured a full v2 respin would easier. Now sent. :) Thanks! -Kees -- Kees Cook
Powered by blists - more mailing lists