Re: [PATCH v2 1/7] capabilities: introduce CAP_SYS_PERFMON to kernel and user space
From: Stephen Smalley <hidden>
Date: 2019-12-16 14:04:12
Also in:
bpf, intel-gfx, linux-perf-users, linux-security-module, lkml, selinux
On 12/16/19 2:14 AM, Alexey Budankov wrote:
Introduce CAP_SYS_PERFMON capability devoted to secure system performance monitoring and observability operations so that CAP_SYS_PERFMON would assist CAP_SYS_ADMIN capability in its governing role for perf_events, i915_perf and other performance monitoring and observability subsystems of the kernel. CAP_SYS_PERFMON intends to harden system security and integrity during system performance monitoring and observability operations by decreasing attack surface that is available to CAP_SYS_ADMIN privileged processes. CAP_SYS_PERFMON intends to take over CAP_SYS_ADMIN credentials related to system performance monitoring and observability operations and balance amount of CAP_SYS_ADMIN credentials following with the recommendations provided in the capabilities man page [1] for CAP_SYS_ADMIN: "Note: this capability is overloaded; see Notes to kernel developers, below." [1] http://man7.org/linux/man-pages/man7/capabilities.7.html Signed-off-by: Alexey Budankov <redacted>
Acked-by: Stephen Smalley <redacted>
quoted hunk ↗ jump to hunk
--- include/uapi/linux/capability.h | 8 +++++++- security/selinux/include/classmap.h | 4 ++-- 2 files changed, 9 insertions(+), 3 deletions(-)diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 240fdb9a60f6..7d1f8606c3e6 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_SYS_PERFMON 38 -#define CAP_LAST_CAP CAP_AUDIT_READ +#define CAP_LAST_CAP CAP_SYS_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..bae602c623b0 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", "sys_perfmon" -#if CAP_LAST_CAP > CAP_AUDIT_READ +#if CAP_LAST_CAP > CAP_SYS_PERFMON #error New capability defined, please update COMMON_CAP2_PERMS. #endif