Fw: [kernel/f13/master] Fix CVE-2010-3080: /dev/sequencer open failure is not handled correctly

[Chuck Ebbert]

Begin forwarded message:

Date: Wed, 15 Sep 2010 02:18:35 +0000 (UTC)
From: Chuck Ebbert <cebbert at fedoraproject.org>
To: kernel-owner at fedoraproject.org, scm-commits at lists.fedoraproject.org
Subject: [kernel/f13/master] Fix CVE-2010-3080: /dev/sequencer open failure is not handled correctly


commit 5bfd09461d7205c2b9fb83f97b00ae3e1ed19058
Author: Chuck Ebbert <cebbert at redhat.com>
Date:   Tue Sep 14 22:17:35 2010 -0400

    Fix CVE-2010-3080: /dev/sequencer open failure is not handled correctly

 ...le-free-at-error-path-of-snd_seq_oss_open.patch |   53 ++++++++++++++++++++
 kernel.spec                                        |    9 +++
 2 files changed, 62 insertions(+), 0 deletions(-)
---
diff --git a/alsa-seq-oss-fix-double-free-at-error-path-of-snd_seq_oss_open.patch b/alsa-seq-oss-fix-double-free-at-error-path-of-snd_seq_oss_open.patch
new file mode 100644
index 0000000..73e65ec
--- /dev/null
+++ b/alsa-seq-oss-fix-double-free-at-error-path-of-snd_seq_oss_open.patch
@@ -0,0 +1,53 @@
+From: Takashi Iwai <tiwai at suse.de>
+Date: Mon, 6 Sep 2010 07:13:45 +0000 (+0200)
+Subject: ALSA: seq/oss - Fix double-free at error path of snd_seq_oss_open()
+X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=27f7ad53829f79e799a253285318bff79ece15bd
+
+ALSA: seq/oss - Fix double-free at error path of snd_seq_oss_open()
+
+The error handling in snd_seq_oss_open() has several bad codes that
+do dereferecing released pointers and double-free of kmalloc'ed data.
+The object dp is release in free_devinfo() that is called via
+private_free callback.  The rest shouldn't touch this object any more.
+
+The patch changes delete_port() to call kfree() in any case, and gets
+rid of unnecessary calls of destructors in snd_seq_oss_open().
+
+Fixes CVE-2010-3080.
+
+Reported-and-tested-by: Tavis Ormandy <taviso at cmpxchg8b.com>
+Cc: <stable at kernel.org>
+Signed-off-by: Takashi Iwai <tiwai at suse.de>
+---
+
+diff --git a/sound/core/seq/oss/seq_oss_init.c b/sound/core/seq/oss/seq_oss_init.c
+index 6857122..69cd7b3 100644
+--- a/sound/core/seq/oss/seq_oss_init.c
++++ b/sound/core/seq/oss/seq_oss_init.c
+@@ -281,13 +281,10 @@ snd_seq_oss_open(struct file *file, int level)
+ 	return 0;
+ 
+  _error:
+-	snd_seq_oss_writeq_delete(dp->writeq);
+-	snd_seq_oss_readq_delete(dp->readq);
+ 	snd_seq_oss_synth_cleanup(dp);
+ 	snd_seq_oss_midi_cleanup(dp);
+-	delete_port(dp);
+ 	delete_seq_queue(dp->queue);
+-	kfree(dp);
++	delete_port(dp);
+ 
+ 	return rc;
+ }
+@@ -350,8 +347,10 @@ create_port(struct seq_oss_devinfo *dp)
+ static int
+ delete_port(struct seq_oss_devinfo *dp)
+ {
+-	if (dp->port < 0)
++	if (dp->port < 0) {
++		kfree(dp);
+ 		return 0;
++	}
+ 
+ 	debug_printk(("delete_port %i\n", dp->port));
+ 	return snd_seq_event_port_detach(dp->cseq, dp->port);
diff --git a/kernel.spec b/kernel.spec
index 90e84f7..15b40a2 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -802,6 +802,9 @@ Patch12540: execve-improve-interactivity-with-large-arguments.patch
 Patch12541: execve-make-responsive-to-sigkill-with-large-arguments.patch
 Patch12542: setup_arg_pages-diagnose-excessive-argument-size.patch
 
+# CVE-2010-3080
+Patch12550: alsa-seq-oss-fix-double-free-at-error-path-of-snd_seq_oss_open.patch
+
 %endif
 
 BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root
@@ -1513,6 +1516,9 @@ ApplyPatch execve-improve-interactivity-with-large-arguments.patch
 ApplyPatch execve-make-responsive-to-sigkill-with-large-arguments.patch
 ApplyPatch setup_arg_pages-diagnose-excessive-argument-size.patch
 
+# CVE-2010-3080
+ApplyPatch alsa-seq-oss-fix-double-free-at-error-path-of-snd_seq_oss_open.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2135,6 +2141,9 @@ fi
 
 %changelog
 * Tue Sep 14 2010 Chuck Ebbert <cebbert at redhat.com> 2.6.34.7-57
+- Fix CVE-2010-3080: /dev/sequencer open failure is not handled correctly
+
+* Tue Sep 14 2010 Chuck Ebbert <cebbert at redhat.com>
 - Fix bug added in 2.6.34.6-53
 
 * Tue Sep 14 2010 Chuck Ebbert <cebbert at redhat.com>