diff options
| author | Xiaoqi Zhuang <xiaoqi.zhuang@oss.qualcomm.com> | 2025-10-21 16:45:25 +0800 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2025-11-05 16:06:06 +0000 |
| commit | 35501ac3c7d40a7bb9568c2f89d6b56beaf9bed3 (patch) | |
| tree | 7969d342abee77dda459e6296dd915c82c442ee9 | |
| parent | dcb6fa37fd7bc9c3d2b066329b0d27dedf8becaa (diff) | |
coresight: ETR: Fix ETR buffer use-after-free issue
When ETR is enabled as CS_MODE_SYSFS, if the buffer size is changed
and enabled again, currently sysfs_buf will point to the newly
allocated memory(buf_new) and free the old memory(buf_old). But the
etr_buf that is being used by the ETR remains pointed to buf_old, not
updated to buf_new. In this case, it will result in a memory
use-after-free issue.
Fix this by checking ETR's mode before updating and releasing buf_old,
if the mode is CS_MODE_SYSFS, then skip updating and releasing it.
Fixes: bd2767ec3df2 ("coresight: Fix run time warnings while reusing ETR buffer")
Signed-off-by: Xiaoqi Zhuang <xiaoqi.zhuang@oss.qualcomm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20251021-fix_etr_issue-v3-1-99a2d066fee2@oss.qualcomm.com
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index b07fcdb3fe1a..800be06598c1 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1250,6 +1250,13 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev) * with the lock released. */ raw_spin_lock_irqsave(&drvdata->spinlock, flags); + + /* + * If the ETR is already enabled, continue with the existing buffer. + */ + if (coresight_get_mode(csdev) == CS_MODE_SYSFS) + goto out; + sysfs_buf = READ_ONCE(drvdata->sysfs_buf); if (!sysfs_buf || (sysfs_buf->size != drvdata->size)) { raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); |