From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Wed, 20 Mar 2019 15:41:09 +0000 (+0100)
Subject: 4.4-stable patches
X-Git-Tag: v3.18.137~79
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=336d90fbc825988a2a78a1dd86c4b78d78837dbc;p=thirdparty%2Fkernel%2Fstable-queue.git

4.4-stable patches

added patches:
	stm-class-prevent-division-by-zero.patch
---

diff --git a/queue-4.4/series b/queue-4.4/series
index ec2c9b898e5..8c44423f4a7 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -174,3 +174,4 @@ phonet-fix-building-with-clang.patch
 mac80211_hwsim-propagate-genlmsg_reply-return-code.patch
 net-set-static-variable-an-initial-value-in-atl2_pro.patch
 tmpfs-fix-uninitialized-return-value-in-shmem_link.patch
+stm-class-prevent-division-by-zero.patch
diff --git a/queue-4.4/stm-class-prevent-division-by-zero.patch b/queue-4.4/stm-class-prevent-division-by-zero.patch
new file mode 100644
index 00000000000..068c886e35b
--- /dev/null
+++ b/queue-4.4/stm-class-prevent-division-by-zero.patch
@@ -0,0 +1,48 @@
+From bf7cbaae0831252b416f375ca9b1027ecd4642dd Mon Sep 17 00:00:00 2001
+From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Date: Thu, 21 Feb 2019 14:19:17 +0200
+Subject: stm class: Prevent division by zero
+
+From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
+
+commit bf7cbaae0831252b416f375ca9b1027ecd4642dd upstream.
+
+Using STP_POLICY_ID_SET ioctl command with dummy_stm device, or any STM
+device that supplies zero mmio channel size, will trigger a division by
+zero bug in the kernel.
+
+Prevent this by disallowing channel widths other than 1 for such devices.
+
+Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
+Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices")
+CC: stable@vger.kernel.org # v4.4+
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/hwtracing/stm/core.c |    8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+--- a/drivers/hwtracing/stm/core.c
++++ b/drivers/hwtracing/stm/core.c
+@@ -477,7 +477,7 @@ static int stm_char_policy_set_ioctl(str
+ {
+ 	struct stm_device *stm = stmf->stm;
+ 	struct stp_policy_id *id;
+-	int ret = -EINVAL;
++	int ret = -EINVAL, wlimit = 1;
+ 	u32 size;
+ 
+ 	if (stmf->output.nr_chans)
+@@ -505,8 +505,10 @@ static int stm_char_policy_set_ioctl(str
+ 	if (id->__reserved_0 || id->__reserved_1)
+ 		goto err_free;
+ 
+-	if (id->width < 1 ||
+-	    id->width > PAGE_SIZE / stm->data->sw_mmiosz)
++	if (stm->data->sw_mmiosz)
++		wlimit = PAGE_SIZE / stm->data->sw_mmiosz;
++
++	if (id->width < 1 || id->width > wlimit)
+ 		goto err_free;
+ 
+ 	ret = stm_file_assign(stmf, id->id, id->width);