From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: gregkh@linuxfoundation.org
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 10/15] coresight: etb10: Fix possible NULL ptr dereference in etb_enable_perf()
Date: Fri, 27 Nov 2020 10:52:51 -0700 [thread overview]
Message-ID: <20201127175256.1092685-11-mathieu.poirier@linaro.org> (raw)
In-Reply-To: <20201127175256.1092685-1-mathieu.poirier@linaro.org>
From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
There was a report of NULL pointer dereference in ETF enable
path for perf CS mode with PID monitoring. It is almost 100%
reproducible when the process to monitor is something very
active such as chrome and with ETF as the sink, not ETR.
But code path shows that ETB has a similar path as ETF, so
there could be possible NULL pointer dereference crash in
ETB as well. Currently in a bid to find the pid, the owner
is dereferenced via task_pid_nr() call in etb_enable_perf()
and with owner being NULL, we can get a NULL pointer
dereference, so have a similar fix as ETF where we cache PID
in alloc_buffer() callback which is called as the part of
etm_setup_aux().
Cc: stable@vger.kernel.org
Fixes: 75d7dbd38824 ("coresight: etb10: Add support for CPU-wide trace scenarios")
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-etb10.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 248cc82c838e..1b320ab581ca 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -176,6 +176,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
unsigned long flags;
struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct perf_output_handle *handle = data;
+ struct cs_buffers *buf = etm_perf_sink_config(handle);
spin_lock_irqsave(&drvdata->spinlock, flags);
@@ -186,7 +187,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
}
/* Get a handle on the pid of the process to monitor */
- pid = task_pid_nr(handle->event->owner);
+ pid = buf->pid;
if (drvdata->pid != -1 && drvdata->pid != pid) {
ret = -EBUSY;
@@ -383,6 +384,7 @@ static void *etb_alloc_buffer(struct coresight_device *csdev,
if (!buf)
return NULL;
+ buf->pid = task_pid_nr(event->owner);
buf->snapshot = overwrite;
buf->nr_pages = nr_pages;
buf->data_pages = pages;
--
2.25.1
next prev parent reply other threads:[~2020-11-27 17:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-27 17:52 [PATCH 00/15] coresight: Patches for v5.11 Mathieu Poirier
2020-11-27 17:52 ` [PATCH 01/15] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up Mathieu Poirier
2020-11-27 17:52 ` [PATCH 02/15] coresight: core: Remove unneeded semicolon Mathieu Poirier
2020-11-27 17:52 ` [PATCH 03/15] coresight: etm4x: Fix accesses to TRCVMIDCTLR1 Mathieu Poirier
2020-11-27 17:52 ` [PATCH 04/15] coresight: etm4x: Fix accesses to TRCCIDCTLR1 Mathieu Poirier
2020-11-27 17:52 ` [PATCH 05/15] coresight: etm4x: Update TRCIDR3.NUMPROCS handling to match v4.2 Mathieu Poirier
2020-11-27 17:52 ` [PATCH 06/15] coresight: etm4x: Fix accesses to TRCPROCSELR Mathieu Poirier
2020-11-27 17:52 ` [PATCH 07/15] coresight: etm4x: Handle TRCVIPCSSCTLR accesses Mathieu Poirier
2020-11-27 17:52 ` [PATCH 08/15] coresight: Remove unnecessary THIS_MODULE of funnel and replicator driver Mathieu Poirier
2020-11-27 17:52 ` [PATCH 09/15] coresight: tmc-etf: Fix NULL ptr dereference in tmc_enable_etf_sink_perf() Mathieu Poirier
2020-11-27 17:52 ` Mathieu Poirier [this message]
2020-11-27 17:52 ` [PATCH 11/15] coresight: tmc-etr: Assign boolean values to a bool variable Mathieu Poirier
2020-11-27 17:52 ` [PATCH 12/15] coresight: tmc-etr: Check if page is valid before dma_map_page() Mathieu Poirier
2020-11-27 17:52 ` [PATCH 13/15] coresight: Fix W=1 warnings in core framework Mathieu Poirier
2020-11-27 17:52 ` [PATCH 14/15] coresight-tpiu: Fix W=1 warning in TPIU driver Mathieu Poirier
2020-11-27 17:52 ` [PATCH 15/15] coresight-stm: Fix W=1 warning in STM driver Mathieu Poirier
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