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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2019-04-17 10:35:35 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-25 11:31:17 +0200
commit51e0f227812ed81a368de54157ebe14396b4be03 (patch)
tree216127d45b587ed6685b798eecd942379b148e1b
parentee496da4c3915de3232b5f5cd20e21ae3e46fe8d (diff)
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@linux.intel.com> Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices") Reported-by: Mulu He <muluhe@codeaurora.org> Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/hwtracing/stm/core.c7
1 files changed, 3 insertions, 4 deletions
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;