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-next>] [day] [month] [year] [list]
Message-ID: <4B6D8ED2.5060107@nctritech.com>
Date:	Sat, 06 Feb 2010 10:46:26 -0500
From:	"Jody@...tech" <jody@...ritech.com>
To:	linux-kernel@...r.kernel.org
Subject: [PATCH] hda-intel: Avoid divide by zero crash

On my AMD780V chipset, hda_intel.c can crash the kernel with a divide by 
zero
for as-yet unknown reasons. A simple check for zero prevents it, though
the problem that causes it remains. Since the workaround is harmless and
won't affect anyone except victims of this bug, it should be safe; 
moreover,
because this crash can be triggered by a user-mode application, there are
denial of service implications on the systems affected by the bug without
the patch.
Signed-off-by: Jody Bruchon <jody@...ritech.com>
--- linux-2.6.33-rc6/sound/pci/hda/hda_intel.c  2010-01-29 
16:57:50.000000000 -0500
+++ linux-2.6.33-rc6-fix/sound/pci/hda/hda_intel.c      2010-02-06 
09:44:10.028348166 -0500
@@ -1878,6 +1878,12 @@

         if (!bdl_pos_adj[chip->dev_index])
                 return 1; /* no delayed ack */
+       if (azx_dev->period_bytes == 0) {
+               printk(KERN_WARNING
+                       "hda-intel: Divide by zero was avoided "
+                       "in azx_dev->period_bytes.\n");
+               return 0;
+       }
         if (pos % azx_dev->period_bytes > azx_dev->period_bytes / 2)
                 return 0; /* NG - it's below the period boundary */
         return 1; /* OK, it's fine */

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ