Messages in this thread Patch in this message | | | From | Djalal Harouni <> | Subject | [PATCH 08/12] procfs: add permission checks on the file's opener of /proc/*/personality | Date | Wed, 25 Sep 2013 21:14:41 +0100 |
| |
If current's cred have changed between ->open() and ->read(), then call proc_allow_access() to check if the original file's opener had enough permissions to access the /proc/*/personality entry during ->read().
Cc: Kees Cook <keescook@chromium.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Djalal Harouni <tixxdz@opendz.org> --- fs/proc/base.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c index d6a17b3..ed8e3f7 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2656,11 +2656,21 @@ static const struct file_operations proc_projid_map_operations = { static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { + const struct cred *fcred = seq_f_cred(m); + int same_cred = proc_same_open_cred(fcred); int err = lock_trace(task); - if (!err) { - seq_printf(m, "%08x\n", task->personality); - unlock_trace(task); + if (err) + return err; + + if (!same_cred && + !proc_allow_access(fcred, task, PTRACE_MODE_ATTACH)) { + err = -EPERM; + goto out; } + + seq_printf(m, "%08x\n", task->personality); +out: + unlock_trace(task); return err; } -- 1.7.11.7
| |