Messages in this thread Patch in this message | | | From | Djalal Harouni <> | Subject | [PATCH v2 7/9] procfs: add permission checks on the file's opener of /proc/*/personality | Date | Tue, 1 Oct 2013 21:26:16 +0100 |
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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 | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c index d4b604d..77f5b84 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2647,11 +2647,23 @@ 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) { + struct file *file = m->private; + const struct cred *fcred = file->f_cred; + 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
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