The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 51e0f227812ed81a368de54157ebe14396b4be03 Mon Sep 17 00:00:00 2001
From: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Date: Wed, 17 Apr 2019 10:35:35 +0300
Subject: [PATCH] stm class: Fix channel bitmap on 32-bit systems
Commit 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace
Module devices") naively calculates the channel bitmap size in 64-bit
chunks regardless of the size of underlying unsigned long, making the
bitmap half as big on a 32-bit system. This leads to an out of bounds
access with the upper half of the bitmap.
Fix this by using BITS_TO_LONGS. While at it, convert to using
struct_size() for the total size calculation of the master struct.
Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices")
Reported-by: Mulu He <muluhe@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index 5b5807cbcf7c..e55b902560de 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -166,11 +166,10 @@ stm_master(struct stm_device *stm, unsigned int idx)
static int stp_master_alloc(struct stm_device *stm, unsigned int idx)
{
struct stp_master *master;
- size_t size;
- size = ALIGN(stm->data->sw_nchannels, 8) / 8;
- size += sizeof(struct stp_master);
- master = kzalloc(size, GFP_ATOMIC);
+ master = kzalloc(struct_size(master, chan_map,
+ BITS_TO_LONGS(stm->data->sw_nchannels)),
+ GFP_ATOMIC);
if (!master)
return -ENOMEM;
