diff options
author | Alex Shi <alex.shi@linaro.org> | 2017-06-15 12:02:40 +0800 |
---|---|---|
committer | Alex Shi <alex.shi@linaro.org> | 2017-06-15 12:02:40 +0800 |
commit | e91e57d305c5b655c672e63eaed6b762d7fa21b5 (patch) | |
tree | 47fccbffb7001a7dd8b2b53db672e0345379b156 /kernel | |
parent | dfb9fdffcea66d74eb9fbe4318471450242790dd (diff) | |
parent | 30c9187fa8ed958e618d2df322b1e4fd5dc591fc (diff) |
Merge tag 'v4.4.72' into linux-linaro-lsk-v4.4
This is the 4.4.72 stable release
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cpuset.c | 4 | ||||
-rw-r--r-- | kernel/events/core.c | 21 | ||||
-rw-r--r-- | kernel/fork.c | 2 | ||||
-rw-r--r-- | kernel/ptrace.c | 20 |
4 files changed, 37 insertions, 10 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index b271353d5202..3b5e5430f5d0 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -173,9 +173,9 @@ typedef enum { } cpuset_flagbits_t; /* convenient tests for these bits */ -static inline bool is_cpuset_online(const struct cpuset *cs) +static inline bool is_cpuset_online(struct cpuset *cs) { - return test_bit(CS_ONLINE, &cs->flags); + return test_bit(CS_ONLINE, &cs->flags) && !css_is_dying(&cs->css); } static inline int is_cpu_exclusive(const struct cpuset *cs) diff --git a/kernel/events/core.c b/kernel/events/core.c index 5b76a66f60fd..65032e5bf772 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6535,6 +6535,21 @@ static void perf_log_itrace_start(struct perf_event *event) perf_output_end(&handle); } +static bool sample_is_allowed(struct perf_event *event, struct pt_regs *regs) +{ + /* + * Due to interrupt latency (AKA "skid"), we may enter the + * kernel before taking an overflow, even if the PMU is only + * counting user events. + * To avoid leaking information to userspace, we must always + * reject kernel samples when exclude_kernel is set. + */ + if (event->attr.exclude_kernel && !user_mode(regs)) + return false; + + return true; +} + /* * Generic event overflow handling, sampling. */ @@ -6582,6 +6597,12 @@ static int __perf_event_overflow(struct perf_event *event, } /* + * For security, drop the skid kernel samples if necessary. + */ + if (!sample_is_allowed(event, regs)) + return ret; + + /* * XXX event_limit might not quite work as expected on inherited * events */ diff --git a/kernel/fork.c b/kernel/fork.c index 0ee630f3ad4b..68cfda1c1800 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -368,7 +368,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) set_task_stack_end_magic(tsk); #ifdef CONFIG_CC_STACKPROTECTOR - tsk->stack_canary = get_random_int(); + tsk->stack_canary = get_random_long(); #endif /* diff --git a/kernel/ptrace.c b/kernel/ptrace.c index c7e8ed99c953..5e2cd1030702 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -28,19 +28,25 @@ #include <linux/compat.h> +void __ptrace_link(struct task_struct *child, struct task_struct *new_parent, + const struct cred *ptracer_cred) +{ + BUG_ON(!list_empty(&child->ptrace_entry)); + list_add(&child->ptrace_entry, &new_parent->ptraced); + child->parent = new_parent; + child->ptracer_cred = get_cred(ptracer_cred); +} + /* * ptrace a task: make the debugger its new parent and * move it to the ptrace list. * * Must be called with the tasklist lock write-held. */ -void __ptrace_link(struct task_struct *child, struct task_struct *new_parent) +static void ptrace_link(struct task_struct *child, struct task_struct *new_parent) { - BUG_ON(!list_empty(&child->ptrace_entry)); - list_add(&child->ptrace_entry, &new_parent->ptraced); - child->parent = new_parent; rcu_read_lock(); - child->ptracer_cred = get_cred(__task_cred(new_parent)); + __ptrace_link(child, new_parent, __task_cred(new_parent)); rcu_read_unlock(); } @@ -353,7 +359,7 @@ static int ptrace_attach(struct task_struct *task, long request, flags |= PT_SEIZED; task->ptrace = flags; - __ptrace_link(task, current); + ptrace_link(task, current); /* SEIZE doesn't trap tracee on attach */ if (!seize) @@ -420,7 +426,7 @@ static int ptrace_traceme(void) */ if (!ret && !(current->real_parent->flags & PF_EXITING)) { current->ptrace = PT_PTRACED; - __ptrace_link(current, current->real_parent); + ptrace_link(current, current->real_parent); } } write_unlock_irq(&tasklist_lock); |