From owner-freebsd-bugs@FreeBSD.ORG Thu Apr 19 20:20:13 2012 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 66086106564A for ; Thu, 19 Apr 2012 20:20:13 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 503A08FC0A for ; Thu, 19 Apr 2012 20:20:13 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.5/8.14.5) with ESMTP id q3JKKCLe002313 for ; Thu, 19 Apr 2012 20:20:12 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.5/8.14.5/Submit) id q3JKKCIv002312; Thu, 19 Apr 2012 20:20:12 GMT (envelope-from gnats) Date: Thu, 19 Apr 2012 20:20:12 GMT Message-Id: <201204192020.q3JKKCIv002312@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: Andreas Longwitz Cc: Subject: Re: kern/155658: [amr] [patch] amr_ioctl(): call of malloc() causes memory corruption and panic X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Andreas Longwitz List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Apr 2012 20:20:13 -0000 The following reply was made to PR kern/155658; it has been noted by GNATS. From: Andreas Longwitz To: John Baldwin Cc: bug-followup@freebsd.org, scottl@freebsd.org Subject: Re: kern/155658: [amr] [patch] amr_ioctl(): call of malloc() causes memory corruption and panic Date: Thu, 19 Apr 2012 22:12:50 +0200 John, I did several tests with your patch in 8.2 and everything works fine, if I use the binary version of megarc with the patch included described in ports/137938. The original megarc sends amr_ioctl's with length 12868 (e.g. the first ioctl of the command "megarc -ctlrinfo -a0") and your patch calls the controller with real_length=16384, but the controller returns 25412 Bytes. This happens all the time on nearly every megarc command, I think this is a program error in megarc, he uses user_cmd=0xa104 with buffer length 12868, but the firmware of the controller replies with 25412 bytes. So we have memory corruption of 25412 - 16384 = 9026 bytes. The patch in ports/137938 changes the lenght field in megarc from 12868 to 25412 to avoid this problem. A line like if( len == 12868 ) len = 25412; would solve this problem in the driver. I did not find any other static problems of this type. Another story are dynamic problems. When the controller is very busy, I see sometimes 1KB bytes returned from the controller, when lenght is much lower. This problem is handled by your patch in all cases. Andreas Longwitz