| Message ID | fd6ffb43-ed43-14cd-b286-6ab4b199155b@linux.intel.com |
|---|---|
| State | Not Applicable |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | Introduce CAP_SYS_PERFMON to secure system performance monitoring and observability | expand |
On Mon, Dec 16, 2019 at 2:15 AM, Alexey Budankov <alexey.budankov@linux.intel.com> wrote: > > Open access to perf_events monitoring for CAP_SYS_PERFMON privileged > processes. > For backward compatibility reasons access to perf_events subsystem remains > open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage > for secure perf_events monitoring is discouraged with respect to > CAP_SYS_PERFMON capability. > > Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> > --- > include/linux/perf_event.h | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index > 34c7c6910026..52313d2cc343 100644 > --- a/include/linux/perf_event.h > +++ b/include/linux/perf_event.h > @@ -1285,7 +1285,8 @@ static inline int perf_is_paranoid(void) > > static inline int perf_allow_kernel(struct perf_event_attr *attr) { > - if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN)) > + if (sysctl_perf_event_paranoid > 1 && > + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) > return -EACCES; > > return security_perf_event_open(attr, PERF_SECURITY_KERNEL); @@ > -1293,7 +1294,8 @@ static inline int perf_allow_kernel(struct > perf_event_attr *attr) > > static inline int perf_allow_cpu(struct perf_event_attr *attr) { > - if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN)) > + if (sysctl_perf_event_paranoid > 0 && > + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) > return -EACCES; > > return security_perf_event_open(attr, PERF_SECURITY_CPU); @@ - > 1301,7 +1303,8 @@ static inline int perf_allow_cpu(struct perf_event_attr > *attr) > > static inline int perf_allow_tracepoint(struct perf_event_attr *attr) { > - if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN)) > + if (sysctl_perf_event_paranoid > -1 && > + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) > return -EPERM; > > return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT); > -- > 2.20.1 Thanks. I like the idea of CAP_SYS_PERFMON that does not require CAP_SYS_ADMIN. It makes granting users ability to run perf a bit safer. I see a lot of "(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN)" constructs now. Maybe wrapping it in an " inline bool perfmon_capable()" defined somewhere (like in /include/linux/capability.h)? - Igor
On 16.12.2019 19:12, Lubashev, Igor wrote: > On Mon, Dec 16, 2019 at 2:15 AM, Alexey Budankov <alexey.budankov@linux.intel.com> wrote: >> >> Open access to perf_events monitoring for CAP_SYS_PERFMON privileged >> processes. >> For backward compatibility reasons access to perf_events subsystem remains >> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage >> for secure perf_events monitoring is discouraged with respect to >> CAP_SYS_PERFMON capability. >> >> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> >> --- >> include/linux/perf_event.h | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index >> 34c7c6910026..52313d2cc343 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -1285,7 +1285,8 @@ static inline int perf_is_paranoid(void) >> >> static inline int perf_allow_kernel(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > 1 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EACCES; >> >> return security_perf_event_open(attr, PERF_SECURITY_KERNEL); @@ >> -1293,7 +1294,8 @@ static inline int perf_allow_kernel(struct >> perf_event_attr *attr) >> >> static inline int perf_allow_cpu(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > 0 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EACCES; >> >> return security_perf_event_open(attr, PERF_SECURITY_CPU); @@ - >> 1301,7 +1303,8 @@ static inline int perf_allow_cpu(struct perf_event_attr >> *attr) >> >> static inline int perf_allow_tracepoint(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > -1 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EPERM; >> >> return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT); >> -- >> 2.20.1 > > Thanks. I like the idea of CAP_SYS_PERFMON that does not require CAP_SYS_ADMIN. It makes granting users ability to run perf a bit safer. > > I see a lot of "(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN)" constructs now. Maybe wrapping it in an " inline bool perfmon_capable()" defined somewhere (like in /include/linux/capability.h)? Yes, it makes sense. Thanks, Alexey > > - Igor >
On 16.12.2019 19:12, Lubashev, Igor wrote: > On Mon, Dec 16, 2019 at 2:15 AM, Alexey Budankov <alexey.budankov@linux.intel.com> wrote: >> >> Open access to perf_events monitoring for CAP_SYS_PERFMON privileged >> processes. >> For backward compatibility reasons access to perf_events subsystem remains >> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage >> for secure perf_events monitoring is discouraged with respect to >> CAP_SYS_PERFMON capability. >> >> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> >> --- >> include/linux/perf_event.h | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index >> 34c7c6910026..52313d2cc343 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -1285,7 +1285,8 @@ static inline int perf_is_paranoid(void) >> >> static inline int perf_allow_kernel(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > 1 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EACCES; >> >> return security_perf_event_open(attr, PERF_SECURITY_KERNEL); @@ >> -1293,7 +1294,8 @@ static inline int perf_allow_kernel(struct >> perf_event_attr *attr) >> >> static inline int perf_allow_cpu(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > 0 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EACCES; >> >> return security_perf_event_open(attr, PERF_SECURITY_CPU); @@ - >> 1301,7 +1303,8 @@ static inline int perf_allow_cpu(struct perf_event_attr >> *attr) >> >> static inline int perf_allow_tracepoint(struct perf_event_attr *attr) { >> - if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN)) >> + if (sysctl_perf_event_paranoid > -1 && >> + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) >> return -EPERM; >> >> return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT); >> -- >> 2.20.1 > > Thanks. I like the idea of CAP_SYS_PERFMON that does not require CAP_SYS_ADMIN. It makes granting users ability to run perf a bit safer. > > I see a lot of "(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN)" constructs now. Maybe wrapping it in an " inline bool perfmon_capable()" defined somewhere (like in /include/linux/capability.h)? Sounds reasonable, thanks! ~Alexey > > - Igor >
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 34c7c6910026..52313d2cc343 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1285,7 +1285,8 @@ static inline int perf_is_paranoid(void) static inline int perf_allow_kernel(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > 1 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > 1 && + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) return -EACCES; return security_perf_event_open(attr, PERF_SECURITY_KERNEL); @@ -1293,7 +1294,8 @@ static inline int perf_allow_kernel(struct perf_event_attr *attr) static inline int perf_allow_cpu(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > 0 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > 0 && + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) return -EACCES; return security_perf_event_open(attr, PERF_SECURITY_CPU); @@ -1301,7 +1303,8 @@ static inline int perf_allow_cpu(struct perf_event_attr *attr) static inline int perf_allow_tracepoint(struct perf_event_attr *attr) { - if (sysctl_perf_event_paranoid > -1 && !capable(CAP_SYS_ADMIN)) + if (sysctl_perf_event_paranoid > -1 && + !(capable(CAP_SYS_PERFMON) || capable(CAP_SYS_ADMIN))) return -EPERM; return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT);
Open access to perf_events monitoring for CAP_SYS_PERFMON privileged processes. For backward compatibility reasons access to perf_events subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure perf_events monitoring is discouraged with respect to CAP_SYS_PERFMON capability. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> --- include/linux/perf_event.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)