Re: [PATCH] proc: add "personality" to process status file

From: Randy.Dunlap
Date: Thu Oct 02 2008 - 18:46:47 EST


On Thu, 2 Oct 2008, Kees Cook wrote:

> There is no sane way to query the personality flags of arbitrary process
> from userspace. This adds the flags to the /proc/$pid/status file.
> For example, to detect READ_IMPLIES_EXEC:
>
> $ ./32bit-sleeper &
> [1] 6732
> $ grep ^Pers /proc/6732/status
> Personality: 00000000
> $ execstack -s 32bit-sleeper
> $ ./32bit-slepper &
> [2] 6735
> $ grep ^Pers /proc/6735/status
> Personality: 00040000
>
> Signed-off-by: Kees Cook <kees.cook@xxxxxxxxxxxxx>
> ---
> fs/proc/array.c | 6 ++++--
> include/linux/sched.h | 3 +--
> 2 files changed, 5 insertions(+), 4 deletions(-)

Hey you,

The patch seems to be missing an update to Documentation/filesystems/proc.txt !
Please add that. TIA.

> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index 71c9be5..1235fab 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -182,13 +182,15 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
> "PPid:\t%d\n"
> "TracerPid:\t%d\n"
> "Uid:\t%d\t%d\t%d\t%d\n"
> - "Gid:\t%d\t%d\t%d\t%d\n",
> + "Gid:\t%d\t%d\t%d\t%d\n"
> + "Personality:\t%08x\n",
> get_task_state(p),
> task_tgid_nr_ns(p, ns),
> pid_nr_ns(pid, ns),
> ppid, tpid,
> p->uid, p->euid, p->suid, p->fsuid,
> - p->gid, p->egid, p->sgid, p->fsgid);
> + p->gid, p->egid, p->sgid, p->fsgid,
> + p->personality);
>
> task_lock(p);
> if (p->files)
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 3d9120c..f2fc441 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1085,8 +1085,7 @@ struct task_struct {
> int exit_state;
> int exit_code, exit_signal;
> int pdeath_signal; /* The signal sent when the parent dies */
> - /* ??? */
> - unsigned int personality;
> + unsigned int personality; /* Special-case bits (linux/personality.h) */
> unsigned did_exec:1;
> pid_t pid;
> pid_t tgid;
>

--
~Randy
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