| Message ID | a4c5da70-b6d1-b133-9b64-34e164834b03@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce CAP_PERFMON to secure system performance monitoring and observability | expand |
On 2/5/20 12:30 PM, Alexey Budankov wrote: > > Introduce CAP_PERFMON capability designed to secure system performance > monitoring and observability operations so that CAP_PERFMON would assist > CAP_SYS_ADMIN capability in its governing role for performance monitoring > and observability subsystems. > > CAP_PERFMON hardens system security and integrity during performance > monitoring and observability operations by decreasing attack surface that > is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access > to system performance monitoring and observability operations under CAP_PERFMON > capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes > chances to misuse the credentials and makes the operation more secure. > Thus, CAP_PERFMON implements the principal of least privilege for performance > monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle > of least privilege: A security design principle that states that a process > or program be granted only those privileges (e.g., capabilities) necessary > to accomplish its legitimate function, and only for the time that such > privileges are actually required) > > CAP_PERFMON meets the demand to secure system performance monitoring and > observability operations for adoption in security sensitive, restricted, > multiuser production environments (e.g. HPC clusters, cloud and virtual compute > environments), where root or CAP_SYS_ADMIN credentials are not available to > mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. > > CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance > monitoring and observability operations and balances amount of CAP_SYS_ADMIN > credentials following the recommendations in the capabilities man page [1] > for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel > developers, below." For backward compatibility reasons access to system > performance monitoring and observability subsystems of the kernel remains > open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability > usage for secure system performance monitoring and observability operations > is discouraged with respect to the designed CAP_PERFMON capability. > > Although the software running under CAP_PERFMON can not ensure avoidance > of related hardware issues, the software can still mitigate these issues > following the official hardware issues mitigation procedure [2]. The bugs > in the software itself can be fixed following the standard kernel development > process [3] to maintain and harden security of system performance monitoring > and observability operations. > > [1] http://man7.org/linux/man-pages/man7/capabilities.7.html > [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html > [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html > > Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> This will require a small update to the selinux-testsuite to correctly reflect the new capability requirements, but that's easy enough. Acked-by: Stephen Smalley <sds@tycho.nsa.gov> > --- > include/linux/capability.h | 4 ++++ > include/uapi/linux/capability.h | 8 +++++++- > security/selinux/include/classmap.h | 4 ++-- > 3 files changed, 13 insertions(+), 3 deletions(-) > > diff --git a/include/linux/capability.h b/include/linux/capability.h > index ecce0f43c73a..027d7e4a853b 100644 > --- a/include/linux/capability.h > +++ b/include/linux/capability.h > @@ -251,6 +251,10 @@ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct > extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); > extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); > extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); > +static inline bool perfmon_capable(void) > +{ > + return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN); > +} > > /* audit system wants to get cap info from files as well */ > extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); > diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h > index 240fdb9a60f6..8b416e5f3afa 100644 > --- a/include/uapi/linux/capability.h > +++ b/include/uapi/linux/capability.h > @@ -366,8 +366,14 @@ struct vfs_ns_cap_data { > > #define CAP_AUDIT_READ 37 > > +/* > + * Allow system performance and observability privileged operations > + * using perf_events, i915_perf and other kernel subsystems > + */ > + > +#define CAP_PERFMON 38 > > -#define CAP_LAST_CAP CAP_AUDIT_READ > +#define CAP_LAST_CAP CAP_PERFMON > > #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) > > diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h > index 7db24855e12d..c599b0c2b0e7 100644 > --- a/security/selinux/include/classmap.h > +++ b/security/selinux/include/classmap.h > @@ -27,9 +27,9 @@ > "audit_control", "setfcap" > > #define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \ > - "wake_alarm", "block_suspend", "audit_read" > + "wake_alarm", "block_suspend", "audit_read", "perfmon" > > -#if CAP_LAST_CAP > CAP_AUDIT_READ > +#if CAP_LAST_CAP > CAP_PERFMON > #error New capability defined, please update COMMON_CAP2_PERMS. > #endif > >
On 06.02.2020 21:23, Stephen Smalley wrote: > On 2/5/20 12:30 PM, Alexey Budankov wrote: >> >> Introduce CAP_PERFMON capability designed to secure system performance >> monitoring and observability operations so that CAP_PERFMON would assist >> CAP_SYS_ADMIN capability in its governing role for performance monitoring >> and observability subsystems. >> >> CAP_PERFMON hardens system security and integrity during performance >> monitoring and observability operations by decreasing attack surface that >> is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access >> to system performance monitoring and observability operations under CAP_PERFMON >> capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes >> chances to misuse the credentials and makes the operation more secure. >> Thus, CAP_PERFMON implements the principal of least privilege for performance >> monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle >> of least privilege: A security design principle that states that a process >> or program be granted only those privileges (e.g., capabilities) necessary >> to accomplish its legitimate function, and only for the time that such >> privileges are actually required) >> >> CAP_PERFMON meets the demand to secure system performance monitoring and >> observability operations for adoption in security sensitive, restricted, >> multiuser production environments (e.g. HPC clusters, cloud and virtual compute >> environments), where root or CAP_SYS_ADMIN credentials are not available to >> mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. >> >> CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance >> monitoring and observability operations and balances amount of CAP_SYS_ADMIN >> credentials following the recommendations in the capabilities man page [1] >> for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel >> developers, below." For backward compatibility reasons access to system >> performance monitoring and observability subsystems of the kernel remains >> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability >> usage for secure system performance monitoring and observability operations >> is discouraged with respect to the designed CAP_PERFMON capability. >> >> Although the software running under CAP_PERFMON can not ensure avoidance >> of related hardware issues, the software can still mitigate these issues >> following the official hardware issues mitigation procedure [2]. The bugs >> in the software itself can be fixed following the standard kernel development >> process [3] to maintain and harden security of system performance monitoring >> and observability operations. >> >> [1] http://man7.org/linux/man-pages/man7/capabilities.7.html >> [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html >> [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html >> >> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> > > This will require a small update to the selinux-testsuite to correctly reflect the new capability requirements, but that's easy enough. Is the suite a part of the kernel sources or something else? ~Alexey > > Acked-by: Stephen Smalley <sds@tycho.nsa.gov> > >> --- >> include/linux/capability.h | 4 ++++ >> include/uapi/linux/capability.h | 8 +++++++- >> security/selinux/include/classmap.h | 4 ++-- >> 3 files changed, 13 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/capability.h b/include/linux/capability.h >> index ecce0f43c73a..027d7e4a853b 100644 >> --- a/include/linux/capability.h >> +++ b/include/linux/capability.h >> @@ -251,6 +251,10 @@ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct >> extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); >> extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); >> extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); >> +static inline bool perfmon_capable(void) >> +{ >> + return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN); >> +} >> /* audit system wants to get cap info from files as well */ >> extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); >> diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h >> index 240fdb9a60f6..8b416e5f3afa 100644 >> --- a/include/uapi/linux/capability.h >> +++ b/include/uapi/linux/capability.h >> @@ -366,8 +366,14 @@ struct vfs_ns_cap_data { >> #define CAP_AUDIT_READ 37 >> +/* >> + * Allow system performance and observability privileged operations >> + * using perf_events, i915_perf and other kernel subsystems >> + */ >> + >> +#define CAP_PERFMON 38 >> -#define CAP_LAST_CAP CAP_AUDIT_READ >> +#define CAP_LAST_CAP CAP_PERFMON >> #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) >> diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h >> index 7db24855e12d..c599b0c2b0e7 100644 >> --- a/security/selinux/include/classmap.h >> +++ b/security/selinux/include/classmap.h >> @@ -27,9 +27,9 @@ >> "audit_control", "setfcap" >> #define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \ >> - "wake_alarm", "block_suspend", "audit_read" >> + "wake_alarm", "block_suspend", "audit_read", "perfmon" >> -#if CAP_LAST_CAP > CAP_AUDIT_READ >> +#if CAP_LAST_CAP > CAP_PERFMON >> #error New capability defined, please update COMMON_CAP2_PERMS. >> #endif >> >
On 2/6/20 1:26 PM, Alexey Budankov wrote: > > On 06.02.2020 21:23, Stephen Smalley wrote: >> On 2/5/20 12:30 PM, Alexey Budankov wrote: >>> >>> Introduce CAP_PERFMON capability designed to secure system performance >>> monitoring and observability operations so that CAP_PERFMON would assist >>> CAP_SYS_ADMIN capability in its governing role for performance monitoring >>> and observability subsystems. >>> >>> CAP_PERFMON hardens system security and integrity during performance >>> monitoring and observability operations by decreasing attack surface that >>> is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access >>> to system performance monitoring and observability operations under CAP_PERFMON >>> capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes >>> chances to misuse the credentials and makes the operation more secure. >>> Thus, CAP_PERFMON implements the principal of least privilege for performance >>> monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle >>> of least privilege: A security design principle that states that a process >>> or program be granted only those privileges (e.g., capabilities) necessary >>> to accomplish its legitimate function, and only for the time that such >>> privileges are actually required) >>> >>> CAP_PERFMON meets the demand to secure system performance monitoring and >>> observability operations for adoption in security sensitive, restricted, >>> multiuser production environments (e.g. HPC clusters, cloud and virtual compute >>> environments), where root or CAP_SYS_ADMIN credentials are not available to >>> mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. >>> >>> CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance >>> monitoring and observability operations and balances amount of CAP_SYS_ADMIN >>> credentials following the recommendations in the capabilities man page [1] >>> for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel >>> developers, below." For backward compatibility reasons access to system >>> performance monitoring and observability subsystems of the kernel remains >>> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability >>> usage for secure system performance monitoring and observability operations >>> is discouraged with respect to the designed CAP_PERFMON capability. >>> >>> Although the software running under CAP_PERFMON can not ensure avoidance >>> of related hardware issues, the software can still mitigate these issues >>> following the official hardware issues mitigation procedure [2]. The bugs >>> in the software itself can be fixed following the standard kernel development >>> process [3] to maintain and harden security of system performance monitoring >>> and observability operations. >>> >>> [1] http://man7.org/linux/man-pages/man7/capabilities.7.html >>> [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html >>> [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html >>> >>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> >> >> This will require a small update to the selinux-testsuite to correctly reflect the new capability requirements, but that's easy enough. > > Is the suite a part of the kernel sources or something else? It is external, https://github.com/SELinuxProject/selinux-testsuite I wasn't suggesting that your patch be blocked on updating the testsuite, just noting that it will need to be done.
On 06.02.2020 21:30, Stephen Smalley wrote: > On 2/6/20 1:26 PM, Alexey Budankov wrote: >> >> On 06.02.2020 21:23, Stephen Smalley wrote: >>> On 2/5/20 12:30 PM, Alexey Budankov wrote: >>>> >>>> Introduce CAP_PERFMON capability designed to secure system performance >>>> monitoring and observability operations so that CAP_PERFMON would assist >>>> CAP_SYS_ADMIN capability in its governing role for performance monitoring >>>> and observability subsystems. >>>> >>>> CAP_PERFMON hardens system security and integrity during performance >>>> monitoring and observability operations by decreasing attack surface that >>>> is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access >>>> to system performance monitoring and observability operations under CAP_PERFMON >>>> capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes >>>> chances to misuse the credentials and makes the operation more secure. >>>> Thus, CAP_PERFMON implements the principal of least privilege for performance >>>> monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle >>>> of least privilege: A security design principle that states that a process >>>> or program be granted only those privileges (e.g., capabilities) necessary >>>> to accomplish its legitimate function, and only for the time that such >>>> privileges are actually required) >>>> >>>> CAP_PERFMON meets the demand to secure system performance monitoring and >>>> observability operations for adoption in security sensitive, restricted, >>>> multiuser production environments (e.g. HPC clusters, cloud and virtual compute >>>> environments), where root or CAP_SYS_ADMIN credentials are not available to >>>> mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. >>>> >>>> CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance >>>> monitoring and observability operations and balances amount of CAP_SYS_ADMIN >>>> credentials following the recommendations in the capabilities man page [1] >>>> for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel >>>> developers, below." For backward compatibility reasons access to system >>>> performance monitoring and observability subsystems of the kernel remains >>>> open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability >>>> usage for secure system performance monitoring and observability operations >>>> is discouraged with respect to the designed CAP_PERFMON capability. >>>> >>>> Although the software running under CAP_PERFMON can not ensure avoidance >>>> of related hardware issues, the software can still mitigate these issues >>>> following the official hardware issues mitigation procedure [2]. The bugs >>>> in the software itself can be fixed following the standard kernel development >>>> process [3] to maintain and harden security of system performance monitoring >>>> and observability operations. >>>> >>>> [1] http://man7.org/linux/man-pages/man7/capabilities.7.html >>>> [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html >>>> [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html >>>> >>>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> >>> >>> This will require a small update to the selinux-testsuite to correctly reflect the new capability requirements, but that's easy enough. >> >> Is the suite a part of the kernel sources or something else? > > It is external, > https://github.com/SELinuxProject/selinux-testsuite > > I wasn't suggesting that your patch be blocked on updating the testsuite, just noting that it will need to be done. Ok. Thanks! ~Alexey
diff --git a/include/linux/capability.h b/include/linux/capability.h index ecce0f43c73a..027d7e4a853b 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -251,6 +251,10 @@ extern bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns); +static inline bool perfmon_capable(void) +{ + return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN); +} /* audit system wants to get cap info from files as well */ extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps); diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 240fdb9a60f6..8b416e5f3afa 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -366,8 +366,14 @@ struct vfs_ns_cap_data { #define CAP_AUDIT_READ 37 +/* + * Allow system performance and observability privileged operations + * using perf_events, i915_perf and other kernel subsystems + */ + +#define CAP_PERFMON 38 -#define CAP_LAST_CAP CAP_AUDIT_READ +#define CAP_LAST_CAP CAP_PERFMON #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 7db24855e12d..c599b0c2b0e7 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -27,9 +27,9 @@ "audit_control", "setfcap" #define COMMON_CAP2_PERMS "mac_override", "mac_admin", "syslog", \ - "wake_alarm", "block_suspend", "audit_read" + "wake_alarm", "block_suspend", "audit_read", "perfmon" -#if CAP_LAST_CAP > CAP_AUDIT_READ +#if CAP_LAST_CAP > CAP_PERFMON #error New capability defined, please update COMMON_CAP2_PERMS. #endif
Introduce CAP_PERFMON capability designed to secure system performance monitoring and observability operations so that CAP_PERFMON would assist CAP_SYS_ADMIN capability in its governing role for performance monitoring and observability subsystems. CAP_PERFMON hardens system security and integrity during performance monitoring and observability operations by decreasing attack surface that is available to a CAP_SYS_ADMIN privileged process [2]. Providing the access to system performance monitoring and observability operations under CAP_PERFMON capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials and makes the operation more secure. Thus, CAP_PERFMON implements the principal of least privilege for performance monitoring and observability operations (POSIX IEEE 1003.1e: 2.2.2.39 principle of least privilege: A security design principle that states that a process or program be granted only those privileges (e.g., capabilities) necessary to accomplish its legitimate function, and only for the time that such privileges are actually required) CAP_PERFMON meets the demand to secure system performance monitoring and observability operations for adoption in security sensitive, restricted, multiuser production environments (e.g. HPC clusters, cloud and virtual compute environments), where root or CAP_SYS_ADMIN credentials are not available to mass users of a system, and securely unblocks accessibility of system performance monitoring and observability operations beyond root and CAP_SYS_ADMIN use cases. CAP_PERFMON takes over CAP_SYS_ADMIN credentials related to system performance monitoring and observability operations and balances amount of CAP_SYS_ADMIN credentials following the recommendations in the capabilities man page [1] for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel developers, below." For backward compatibility reasons access to system performance monitoring and observability subsystems of the kernel remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN capability usage for secure system performance monitoring and observability operations is discouraged with respect to the designed CAP_PERFMON capability. Although the software running under CAP_PERFMON can not ensure avoidance of related hardware issues, the software can still mitigate these issues following the official hardware issues mitigation procedure [2]. The bugs in the software itself can be fixed following the standard kernel development process [3] to maintain and harden security of system performance monitoring and observability operations. [1] http://man7.org/linux/man-pages/man7/capabilities.7.html [2] https://www.kernel.org/doc/html/latest/process/embargoed-hardware-issues.html [3] https://www.kernel.org/doc/html/latest/admin-guide/security-bugs.html Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> --- include/linux/capability.h | 4 ++++ include/uapi/linux/capability.h | 8 +++++++- security/selinux/include/classmap.h | 4 ++-- 3 files changed, 13 insertions(+), 3 deletions(-)