From: Leo Yan <leo.yan@linaro.org> To: Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, James Clark <james.clark@arm.com>, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace Date: Sun, 31 Oct 2021 22:42:12 +0800 [thread overview] Message-ID: <20211031144214.237879-3-leo.yan@linaro.org> (raw) In-Reply-To: <20211031144214.237879-1-leo.yan@linaro.org> As commented in the function ctxid_pid_store(), it can cause the PID values mismatching between context ID tracing and PID allocated in a non-root namespace, and it can leak kernel information. For this reason, when a process runs in non-root PID namespace, the driver doesn't allow contextID tracing and returns failure when access contextID related sysfs nodes. VMID works for virtual contextID when the kernel runs in EL2 mode with VHE; on the other hand, the driver doesn't prevent users from accessing it when programs run in the non-root namespace. Thus this can lead to same issues with contextID described above. This patch imposes the checking on VMID related sysfs knobs, it returns failure if current process runs in non-root PID namespace. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- .../coresight/coresight-etm4x-sysfs.c | 28 +++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index e4c8c44d04ef..e218281703b0 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2111,6 +2111,13 @@ static ssize_t vmid_val_show(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + spin_lock(&drvdata->spinlock); val = (unsigned long)config->vmid_val[config->vmid_idx]; spin_unlock(&drvdata->spinlock); @@ -2125,6 +2132,13 @@ static ssize_t vmid_val_store(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + /* * only implemented when vmid tracing is enabled, i.e. at least one * vmid comparator is implemented and at least 8 bit vmid size @@ -2148,6 +2162,13 @@ static ssize_t vmid_masks_show(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + spin_lock(&drvdata->spinlock); val1 = config->vmid_mask0; val2 = config->vmid_mask1; @@ -2165,6 +2186,13 @@ static ssize_t vmid_masks_store(struct device *dev, struct etmv4_config *config = &drvdata->config; int nr_inputs; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + /* * only implemented when vmid tracing is enabled, i.e. at least one * vmid comparator is implemented and at least 8 bit vmid size -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Leo Yan <leo.yan@linaro.org> To: Mathieu Poirier <mathieu.poirier@linaro.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, Mike Leach <mike.leach@linaro.org>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, James Clark <james.clark@arm.com>, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace Date: Sun, 31 Oct 2021 22:42:12 +0800 [thread overview] Message-ID: <20211031144214.237879-3-leo.yan@linaro.org> (raw) In-Reply-To: <20211031144214.237879-1-leo.yan@linaro.org> As commented in the function ctxid_pid_store(), it can cause the PID values mismatching between context ID tracing and PID allocated in a non-root namespace, and it can leak kernel information. For this reason, when a process runs in non-root PID namespace, the driver doesn't allow contextID tracing and returns failure when access contextID related sysfs nodes. VMID works for virtual contextID when the kernel runs in EL2 mode with VHE; on the other hand, the driver doesn't prevent users from accessing it when programs run in the non-root namespace. Thus this can lead to same issues with contextID described above. This patch imposes the checking on VMID related sysfs knobs, it returns failure if current process runs in non-root PID namespace. Signed-off-by: Leo Yan <leo.yan@linaro.org> --- .../coresight/coresight-etm4x-sysfs.c | 28 +++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index e4c8c44d04ef..e218281703b0 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2111,6 +2111,13 @@ static ssize_t vmid_val_show(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + spin_lock(&drvdata->spinlock); val = (unsigned long)config->vmid_val[config->vmid_idx]; spin_unlock(&drvdata->spinlock); @@ -2125,6 +2132,13 @@ static ssize_t vmid_val_store(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + /* * only implemented when vmid tracing is enabled, i.e. at least one * vmid comparator is implemented and at least 8 bit vmid size @@ -2148,6 +2162,13 @@ static ssize_t vmid_masks_show(struct device *dev, struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); struct etmv4_config *config = &drvdata->config; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + spin_lock(&drvdata->spinlock); val1 = config->vmid_mask0; val2 = config->vmid_mask1; @@ -2165,6 +2186,13 @@ static ssize_t vmid_masks_store(struct device *dev, struct etmv4_config *config = &drvdata->config; int nr_inputs; + /* + * Don't use virtual contextID tracing if coming from a PID namespace. + * See comment in ctxid_pid_store(). + */ + if (task_active_pid_ns(current) != &init_pid_ns) + return -EINVAL; + /* * only implemented when vmid tracing is enabled, i.e. at least one * vmid comparator is implemented and at least 8 bit vmid size -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-10-31 14:42 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-10-31 14:42 [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Leo Yan 2021-10-31 14:42 ` Leo Yan 2021-10-31 14:42 ` [PATCH v1 1/4] coresight: etm4x: Add lock for reading virtual context ID comparator Leo Yan 2021-10-31 14:42 ` Leo Yan 2021-11-01 9:49 ` Suzuki K Poulose 2021-11-01 9:49 ` Suzuki K Poulose 2021-11-01 10:59 ` Leo Yan 2021-11-01 10:59 ` Leo Yan 2021-10-31 14:42 ` Leo Yan [this message] 2021-10-31 14:42 ` [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace Leo Yan 2021-11-04 15:07 ` Suzuki K Poulose 2021-11-04 15:07 ` Suzuki K Poulose 2021-11-04 15:24 ` Leo Yan 2021-11-04 15:24 ` Leo Yan 2021-10-31 14:42 ` [PATCH v1 3/4] coresight: etm4x: Don't trace contextID for non-root namespace in perf mode Leo Yan 2021-10-31 14:42 ` Leo Yan 2021-11-16 9:46 ` Suzuki K Poulose 2021-11-16 9:46 ` Suzuki K Poulose 2021-11-17 13:53 ` Leo Yan 2021-11-17 13:53 ` Leo Yan 2021-10-31 14:42 ` [PATCH v1 4/4] coresight: etm3x: " Leo Yan 2021-10-31 14:42 ` Leo Yan 2021-11-16 13:52 ` [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Suzuki K Poulose 2021-11-16 13:52 ` Suzuki K Poulose
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20211031144214.237879-3-leo.yan@linaro.org \ --to=leo.yan@linaro.org \ --cc=alexander.shishkin@linux.intel.com \ --cc=coresight@lists.linaro.org \ --cc=james.clark@arm.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=mathieu.poirier@linaro.org \ --cc=mike.leach@linaro.org \ --cc=suzuki.poulose@arm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.