[kernel] CVE-XXXX-XXXX potential memory corruption in vhost/scsi driver (rhbz 1189864 1192079)

[Josh Boyer]

commit c438599162b0da1365ac1ea1a03e16586fc47e77
Author: Josh Boyer <jwboyer at fedoraproject.org>
Date:   Mon Feb 16 14:32:42 2015 -0500

    CVE-XXXX-XXXX potential memory corruption in vhost/scsi driver (rhbz 1189864 1192079)

 kernel.spec                                  |    7 +++
 vhost-scsi-potential-memory-corruption.patch |   53 ++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 0 deletions(-)
---
diff --git a/kernel.spec b/kernel.spec
index 78e8c3b..0907b47 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -620,6 +620,9 @@ Patch26134: perf-tools-Define-_GNU_SOURCE-on-pthread_attr_setaff.patch
 #CVE-2015-1593 rhbz 1192519 1192520
 Patch26135: ASLR-fix-stack-randomization-on-64-bit-systems.patch
 
+#CVE-XXXX-XXXX rhbz 1189864 1192079
+Patch26136: vhost-scsi-potential-memory-corruption.patch
+
 # git clone ssh://git.fedorahosted.org/git/kernel-arm64.git, git diff master...devel
 Patch30000: kernel-arm64.patch
 
@@ -1349,6 +1352,9 @@ ApplyPatch perf-tools-Define-_GNU_SOURCE-on-pthread_attr_setaff.patch
 #CVE-2015-1593 rhbz 1192519 1192520
 ApplyPatch ASLR-fix-stack-randomization-on-64-bit-systems.patch
 
+#CVE-XXXX-XXXX rhbz 1189864 1192079
+ApplyPatch vhost-scsi-potential-memory-corruption.patch
+
 %if 0%{?aarch64patches}
 ApplyPatch kernel-arm64.patch
 %ifnarch aarch64 # this is stupid, but i want to notice before secondary koji does.
@@ -2216,6 +2222,7 @@ fi
 #                                    ||     ||
 %changelog
 * Mon Feb 16 2015 Josh Boyer <jwboyer at fedoraproject.org>
+- CVE-XXXX-XXXX potential memory corruption in vhost/scsi driver (rhbz 1189864 1192079)
 - CVE-2015-1593 stack ASLR integer overflow (rhbz 1192519 1192520)
 
 * Mon Feb 16 2015 Peter Robinson <pbrobinson at fedoraproject.org>
diff --git a/vhost-scsi-potential-memory-corruption.patch b/vhost-scsi-potential-memory-corruption.patch
new file mode 100644
index 0000000..08a75a5
--- /dev/null
+++ b/vhost-scsi-potential-memory-corruption.patch
@@ -0,0 +1,53 @@
+From: Dan Carpenter <dan.carpenter at oracle.com>
+Date: Thu, 5 Feb 2015 10:37:33 +0300
+Subject: [PATCH] vhost/scsi: potential memory corruption
+
+This code in vhost_scsi_make_tpg() is confusing because we limit "tpgt"
+to UINT_MAX but the data type of "tpg->tport_tpgt" and that is a u16.
+
+I looked at the context and it turns out that in
+vhost_scsi_set_endpoint(), "tpg->tport_tpgt" is used as an offset into
+the vs_tpg[] array which has VHOST_SCSI_MAX_TARGET (256) elements so
+anything higher than 255 then it is invalid.  I have made that the limit
+now.
+
+In vhost_scsi_send_evt() we mask away values higher than 255, but now
+that the limit has changed, we don't need the mask.
+
+Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
+Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
+---
+ drivers/vhost/scsi.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
+index dc78d87e0fc2..d27cfb20776f 100644
+--- a/drivers/vhost/scsi.c
++++ b/drivers/vhost/scsi.c
+@@ -1253,7 +1253,7 @@ tcm_vhost_send_evt(struct vhost_scsi *vs,
+ 		 * lun[4-7] need to be zero according to virtio-scsi spec.
+ 		 */
+ 		evt->event.lun[0] = 0x01;
+-		evt->event.lun[1] = tpg->tport_tpgt & 0xFF;
++		evt->event.lun[1] = tpg->tport_tpgt;
+ 		if (lun->unpacked_lun >= 256)
+ 			evt->event.lun[2] = lun->unpacked_lun >> 8 | 0x40 ;
+ 		evt->event.lun[3] = lun->unpacked_lun & 0xFF;
+@@ -2124,12 +2124,12 @@ tcm_vhost_make_tpg(struct se_wwn *wwn,
+ 			struct tcm_vhost_tport, tport_wwn);
+ 
+ 	struct tcm_vhost_tpg *tpg;
+-	unsigned long tpgt;
++	u16 tpgt;
+ 	int ret;
+ 
+ 	if (strstr(name, "tpgt_") != name)
+ 		return ERR_PTR(-EINVAL);
+-	if (kstrtoul(name + 5, 10, &tpgt) || tpgt > UINT_MAX)
++	if (kstrtou16(name + 5, 10, &tpgt) || tpgt >= VHOST_SCSI_MAX_TARGET)
+ 		return ERR_PTR(-EINVAL);
+ 
+ 	tpg = kzalloc(sizeof(struct tcm_vhost_tpg), GFP_KERNEL);
+-- 
+2.1.0
+