From e92b6ef8fc963a068ff70188fb0458b1eeaa7175 Mon Sep 17 00:00:00 2001 From: Jeff Vander Stoep Date: Thu, 23 Jan 2020 09:51:14 +0100 Subject: [PATCH] Revert "ANDROID: security,perf: Allow further restriction of perf_event_open" Unfork Android. This reverts commit 5dbd8df7b35643210226329bd7e60658c07a036f. Perf_event_paranoid=3 is no longer needed on Android. Access control of perf events is now done by selinux. See: https://patchwork.kernel.org/patch/11185793/ IGNORE_MERGE_CONFLICT_CHECK==kernel.rst documentation uses "====". Bug: 120445712 Bug: 137092007 Signed-off-by: Jeff Vander Stoep Change-Id: Iba493424174b30baff460caaa25a54a472c87bd4 --- Documentation/admin-guide/sysctl/kernel.rst | 5 +---- arch/arm64/configs/gki_defconfig | 1 - arch/x86/configs/gki_defconfig | 1 - kernel/events/core.c | 5 ----- security/Kconfig | 9 --------- 5 files changed, 1 insertion(+), 20 deletions(-) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 92a709f96012..def074807cee 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -720,8 +720,7 @@ perf_event_paranoid: ==================== Controls use of the performance events system by unprivileged -users (without CAP_SYS_ADMIN). The default value is 3 if -CONFIG_SECURITY_PERF_EVENTS_RESTRICT is set, or 2 otherwise. +users (without CAP_SYS_ADMIN). The default value is 2. === ================================================================== -1 Allow use of (almost) all events by all users @@ -735,8 +734,6 @@ CONFIG_SECURITY_PERF_EVENTS_RESTRICT is set, or 2 otherwise. >=1 Disallow CPU event access by users without CAP_SYS_ADMIN >=2 Disallow kernel profiling by users without CAP_SYS_ADMIN - ->=3: Disallow all event access by users without CAP_SYS_ADMIN === ================================================================== diff --git a/arch/arm64/configs/gki_defconfig b/arch/arm64/configs/gki_defconfig index ddc2b7848979..6d4aecd3c7b7 100644 --- a/arch/arm64/configs/gki_defconfig +++ b/arch/arm64/configs/gki_defconfig @@ -470,7 +470,6 @@ CONFIG_NLS_MAC_INUIT=y CONFIG_NLS_MAC_ROMANIAN=y CONFIG_NLS_MAC_TURKISH=y CONFIG_NLS_UTF8=y -CONFIG_SECURITY_PERF_EVENTS_RESTRICT=y CONFIG_SECURITY=y CONFIG_SECURITY_NETWORK=y CONFIG_HARDENED_USERCOPY=y diff --git a/arch/x86/configs/gki_defconfig b/arch/x86/configs/gki_defconfig index 4cc494239483..f767e5b06e99 100644 --- a/arch/x86/configs/gki_defconfig +++ b/arch/x86/configs/gki_defconfig @@ -403,7 +403,6 @@ CONFIG_NLS_MAC_INUIT=y CONFIG_NLS_MAC_ROMANIAN=y CONFIG_NLS_MAC_TURKISH=y CONFIG_NLS_UTF8=y -CONFIG_SECURITY_PERF_EVENTS_RESTRICT=y CONFIG_SECURITY=y CONFIG_SECURITY_NETWORK=y CONFIG_HARDENED_USERCOPY=y diff --git a/kernel/events/core.c b/kernel/events/core.c index cba40762e802..d5a71cde9adb 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -398,13 +398,8 @@ static cpumask_var_t perf_online_mask; * 0 - disallow raw tracepoint access for unpriv * 1 - disallow cpu events for unpriv * 2 - disallow kernel profiling for unpriv - * 3 - disallow all unpriv perf event use */ -#ifdef CONFIG_SECURITY_PERF_EVENTS_RESTRICT -int sysctl_perf_event_paranoid __read_mostly = 3; -#else int sysctl_perf_event_paranoid __read_mostly = 2; -#endif /* Minimum for 512 kiB + 1 user control page */ int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ diff --git a/security/Kconfig b/security/Kconfig index c66f43a36dbe..2a1a2d396228 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -19,15 +19,6 @@ config SECURITY_DMESG_RESTRICT If you are unsure how to answer this question, answer N. -config SECURITY_PERF_EVENTS_RESTRICT - bool "Restrict unprivileged use of performance events" - depends on PERF_EVENTS - help - If you say Y here, the kernel.perf_event_paranoid sysctl - will be set to 3 by default, and no unprivileged use of the - perf_event_open syscall will be permitted unless it is - changed. - config SECURITY bool "Enable different security models" depends on SYSFS