diff options
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 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 2 |
5 files changed, 38 insertions, 11 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 784ab8fe8714..22350b15b4e7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6410,6 +6410,21 @@ 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. */ @@ -6457,6 +6472,12 @@ 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); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4c21c0b7dc91..e81be0460cc7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1617,7 +1617,7 @@ static void __trace_find_cmdline(int pid, char comm[]) map = savedcmd->map_pid_to_cmdline[pid]; if (map != NO_CMDLINE_MAP) - strcpy(comm, get_saved_cmdlines(map)); + strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN); else strcpy(comm, "<...>"); } |