diff options
| -rw-r--r-- | kernel/futex.c | 36 | ||||
| -rw-r--r-- | kernel/futex_compat.c | 36 |
2 files changed, 26 insertions, 46 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 067702335762..866c9d5959dd 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -59,6 +59,7 @@ #include <linux/magic.h> #include <linux/pid.h> #include <linux/nsproxy.h> +#include <linux/ptrace.h> #include <asm/futex.h> @@ -2443,40 +2444,29 @@ SYSCALL_DEFINE3(get_robust_list, int, pid, { struct robust_list_head __user *head; unsigned long ret; - const struct cred *cred = current_cred(), *pcred; + struct task_struct *p; if (!futex_cmpxchg_enabled) return -ENOSYS; + rcu_read_lock(); + + ret = -ESRCH; if (!pid) - head = current->robust_list; + p = current; else { - struct task_struct *p; - - ret = -ESRCH; - rcu_read_lock(); p = find_task_by_vpid(pid); if (!p) goto err_unlock; - ret = -EPERM; - pcred = __task_cred(p); - /* If victim is in different user_ns, then uids are not - comparable, so we must have CAP_SYS_PTRACE */ - if (cred->user->user_ns != pcred->user->user_ns) { - if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE)) - goto err_unlock; - goto ok; - } - /* If victim is in same user_ns, then uids are comparable */ - if (cred->euid != pcred->euid && - cred->euid != pcred->uid && - !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE)) - goto err_unlock; -ok: - head = p->robust_list; - rcu_read_unlock(); } + ret = -EPERM; + if (!ptrace_may_access(p, PTRACE_MODE_READ)) + goto err_unlock; + + head = p->robust_list; + rcu_read_unlock(); + if (put_user(sizeof(*head), len_ptr)) return -EFAULT; return put_user(head, head_ptr); diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 5f9e689dc8f0..a9642d528630 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -10,6 +10,7 @@ #include <linux/compat.h> #include <linux/nsproxy.h> #include <linux/futex.h> +#include <linux/ptrace.h> #include <asm/uaccess.h> @@ -136,40 +137,29 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr, { struct compat_robust_list_head __user *head; unsigned long ret; - const struct cred *cred = current_cred(), *pcred; + struct task_struct *p; if (!futex_cmpxchg_enabled) return -ENOSYS; + rcu_read_lock(); + + ret = -ESRCH; if (!pid) - head = current->compat_robust_list; + p = current; else { - struct task_struct *p; - - ret = -ESRCH; - rcu_read_lock(); p = find_task_by_vpid(pid); if (!p) goto err_unlock; - ret = -EPERM; - pcred = __task_cred(p); - /* If victim is in different user_ns, then uids are not - comparable, so we must have CAP_SYS_PTRACE */ - if (cred->user->user_ns != pcred->user->user_ns) { - if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE)) - goto err_unlock; - goto ok; - } - /* If victim is in same user_ns, then uids are comparable */ - if (cred->euid != pcred->euid && - cred->euid != pcred->uid && - !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE)) - goto err_unlock; -ok: - head = p->compat_robust_list; - rcu_read_unlock(); } + ret = -EPERM; + if (!ptrace_may_access(p, PTRACE_MODE_READ)) + goto err_unlock; + + head = p->compat_robust_list; + rcu_read_unlock(); + if (put_user(sizeof(*head), len_ptr)) return -EFAULT; return put_user(ptr_to_compat(head), head_ptr); |