[PATCH v2] proc: show personality via /proc/pid/personality

Kees Cook
2008-10-05T10:15:11Z

Make process personality flags visible in /proc. Since a process's
personality is potentially sensitive (e.g. READ_IMPLIES_EXEC), make this
file only readable by the process owner.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
---
Please revert the prior patch against the "status" file -- this is the
alternative.
---
fs/proc/array.c | 8 ++++++++
fs/proc/base.c | 2 ++
fs/proc/internal.h | 2 ++
3 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 71c9be5..6b6b492 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -337,6 +337,14 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
return 0;
}

+int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task)
+{
+ seq_printf(m, "%08x\n", task->personality);
+
+ return 0;
+}
+
static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task, int whole)
{
diff --git a/fs/proc/base.c b/fs/proc/base.c
index a28840b..c675c62 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2459,6 +2459,7 @@ static const struct pid_entry tgid_base_stuff[] = {
REG("environ", S_IRUSR, environ),
INF("auxv", S_IRUSR, pid_auxv),
ONE("status", S_IRUGO, pid_status),
+ ONE("personality", S_IRUSR, pid_personality),
INF("limits", S_IRUSR, pid_limits),
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, pid_sched),
@@ -2794,6 +2795,7 @@ static const struct pid_entry tid_base_stuff[] = {
REG("environ", S_IRUSR, environ),
INF("auxv", S_IRUSR, pid_auxv),
ONE("status", S_IRUGO, pid_status),
+ ONE("personality", S_IRUSR, pid_personality),
INF("limits", S_IRUSR, pid_limits),
#ifdef CONFIG_SCHED_DEBUG
REG("sched", S_IRUGO|S_IWUSR, pid_sched),
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 4422023..747e3de 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -53,6 +53,8 @@ extern int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task);
extern int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task);
+extern int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
+ struct pid *pid, struct task_struct *task);
extern int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *task);
extern loff_t mem_lseek(struct file *file, loff_t offset, int orig);
--
1.5.6.3

--
Kees Cook
Ubuntu Security Team