diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0052-seccomp-Enable-speculation-flaw-mitigations.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0052-seccomp-Enable-speculation-flaw-mitigations.patch | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0052-seccomp-Enable-speculation-flaw-mitigations.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0052-seccomp-Enable-speculation-flaw-mitigations.patch new file mode 100644 index 00000000..85ed7f13 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0052-seccomp-Enable-speculation-flaw-mitigations.patch @@ -0,0 +1,64 @@ +From 6afc277e9b6b9bf8bb4c8c2e4641a021f9d709e2 Mon Sep 17 00:00:00 2001 +From: Kees Cook <keescook@chromium.org> +Date: Tue, 1 May 2018 15:07:31 -0700 +Subject: [PATCH 52/93] seccomp: Enable speculation flaw mitigations + +commit 5c3070890d06ff82eecb808d02d2ca39169533ef upstream + +When speculation flaw mitigations are opt-in (via prctl), using seccomp +will automatically opt-in to these protections, since using seccomp +indicates at least some level of sandboxing is desired. + +Signed-off-by: Kees Cook <keescook@chromium.org> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + kernel/seccomp.c | 17 +++++++++++++++++ + 1 file changed, 17 insertions(+) + +diff --git a/kernel/seccomp.c b/kernel/seccomp.c +index af182a6..1d3078b 100644 +--- a/kernel/seccomp.c ++++ b/kernel/seccomp.c +@@ -16,6 +16,8 @@ + #include <linux/atomic.h> + #include <linux/audit.h> + #include <linux/compat.h> ++#include <linux/nospec.h> ++#include <linux/prctl.h> + #include <linux/sched.h> + #include <linux/seccomp.h> + #include <linux/slab.h> +@@ -214,6 +216,19 @@ static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode) + return true; + } + ++/* ++ * If a given speculation mitigation is opt-in (prctl()-controlled), ++ * select it, by disabling speculation (enabling mitigation). ++ */ ++static inline void spec_mitigate(struct task_struct *task, ++ unsigned long which) ++{ ++ int state = arch_prctl_spec_ctrl_get(task, which); ++ ++ if (state > 0 && (state & PR_SPEC_PRCTL)) ++ arch_prctl_spec_ctrl_set(task, which, PR_SPEC_DISABLE); ++} ++ + static inline void seccomp_assign_mode(struct task_struct *task, + unsigned long seccomp_mode) + { +@@ -225,6 +240,8 @@ static inline void seccomp_assign_mode(struct task_struct *task, + * filter) is set. + */ + smp_mb__before_atomic(); ++ /* Assume seccomp processes want speculation flaw mitigation. */ ++ spec_mitigate(task, PR_SPEC_STORE_BYPASS); + set_tsk_thread_flag(task, TIF_SECCOMP); + } + +-- +2.7.4 + |