diff options
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 60 |
1 files changed, 19 insertions, 41 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 4f08b17d6426..3f0cb82e4fbc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2239,7 +2239,7 @@ static void __perf_event_disable(struct perf_event *event, * * If event->ctx is a cloned context, callers must make sure that * every task struct that event->ctx->task could possibly point to - * remains valid. This condition is satisifed when called through + * remains valid. This condition is satisfied when called through * perf_event_for_each_child or perf_event_for_each because they * hold the top-level event's child_mutex, so any descendant that * goes to exit will block in perf_event_exit_event(). @@ -6054,7 +6054,7 @@ static void perf_sample_regs_intr(struct perf_regs *regs_intr, * Get remaining task size from user stack pointer. * * It'd be better to take stack vma map and limit this more - * precisly, but there's no way to get it safely under interrupt, + * precisely, but there's no way to get it safely under interrupt, * so using TASK_SIZE as limit. */ static u64 perf_ustack_task_size(struct pt_regs *regs) @@ -6616,7 +6616,7 @@ void perf_prepare_sample(struct perf_event_header *header, if (sample_type & PERF_SAMPLE_STACK_USER) { /* - * Either we need PERF_SAMPLE_STACK_USER bit to be allways + * Either we need PERF_SAMPLE_STACK_USER bit to be always * processed as the last one or have additional check added * in case new sample type is added, because we could eat * up the rest of the sample size. @@ -10586,55 +10586,26 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr, u32 size; int ret; - if (!access_ok(uattr, PERF_ATTR_SIZE_VER0)) - return -EFAULT; - - /* - * zero the full structure, so that a short copy will be nice. - */ + /* Zero the full structure, so that a short copy will be nice. */ memset(attr, 0, sizeof(*attr)); ret = get_user(size, &uattr->size); if (ret) return ret; - if (size > PAGE_SIZE) /* silly large */ - goto err_size; - - if (!size) /* abi compat */ + /* ABI compatibility quirk: */ + if (!size) size = PERF_ATTR_SIZE_VER0; - - if (size < PERF_ATTR_SIZE_VER0) + if (size < PERF_ATTR_SIZE_VER0 || size > PAGE_SIZE) goto err_size; - /* - * If we're handed a bigger struct than we know of, - * ensure all the unknown bits are 0 - i.e. new - * user-space does not rely on any kernel feature - * extensions we dont know about yet. - */ - if (size > sizeof(*attr)) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; - - addr = (void __user *)uattr + sizeof(*attr); - end = (void __user *)uattr + size; - - for (; addr < end; addr++) { - ret = get_user(val, addr); - if (ret) - return ret; - if (val) - goto err_size; - } - size = sizeof(*attr); + ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); + if (ret) { + if (ret == -E2BIG) + goto err_size; + return ret; } - ret = copy_from_user(attr, uattr, size); - if (ret) - return -EFAULT; - attr->size = size; if (attr->__reserved_1) @@ -10917,6 +10888,13 @@ SYSCALL_DEFINE5(perf_event_open, perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) return -EACCES; + err = security_locked_down(LOCKDOWN_PERF); + if (err && (attr.sample_type & PERF_SAMPLE_REGS_INTR)) + /* REGS_INTR can leak data, lockdown must prevent this */ + return err; + + err = 0; + /* * In cgroup mode, the pid argument is used to pass the fd * opened to the cgroup directory in cgroupfs. The cpu argument |
