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
| ||
|
Date: Sun, 10 May 2015 19:22:17 -0400 (EDT) From: David Miller <davem@...emloft.net> To: nschichan@...ebox.fr Cc: linux@....linux.org.uk, ast@...mgrid.com, daniel@...earbox.net, mgherzan@...il.com, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org Subject: Re: [PATCH] ARM: net: delegate filter to kernel interpreter when imm_offset() return value can't fit into 12bits. From: Nicolas Schichan <nschichan@...ebox.fr> Date: Thu, 7 May 2015 17:14:21 +0200 > The ARM JIT code emits "ldr rX, [pc, #offset]" to access the literal > pool. #offset maximum value is 4095 and if the generated code is too > large, the #offset value can overflow and not point to the expected > slot in the literal pool. Additionally, when overflow occurs, bits of > the overflow can end up changing the destination register of the ldr > instruction. > > Fix that by detecting the overflow in imm_offset() and setting a flag > that is checked for each BPF instructions converted in > build_body(). As of now it can only be detected in the second pass. As > a result the second build_body() call can now fail, so add the > corresponding cleanup code in that case. > > Using multiple literal pools in the JITed code is going to require > lots of intrusive changes to the JIT code (which would better be done > as a feature instead of fix), just delegating to the kernel BPF > interpreter in that case is a more straight forward, minimal fix and > easy to backport. > > Signed-off-by: Nicolas Schichan <nschichan@...ebox.fr> Applied, thanks Nicolas. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists