From: tixxdz@gmail.com (Djalal Harouni)
To: linux-security-module@vger.kernel.org
Subject: [PATCH RFC v2 5/6] proc: instantiate only pids that we can ptrace on 'limit_pids=1' mount option
Date: Tue, 25 Apr 2017 14:23:57 +0200 [thread overview]
Message-ID: <1493123038-30590-6-git-send-email-tixxdz@gmail.com> (raw)
In-Reply-To: <1493123038-30590-1-git-send-email-tixxdz@gmail.com>
If "limit_pids=1" mount option is set then do not instantiate pids that
we can not ptrace. "limit_pids=1" means that procfs should only contain
pids that the caller can ptrace.
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Djalal Harouni <tixxdz@gmail.com>
---
fs/proc/base.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 2e0f661..a663284 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -3149,6 +3149,7 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsign
unsigned tgid;
struct proc_fs_info *fs_info = proc_sb(dir->i_sb);
struct pid_namespace *ns = fs_info->pid_ns;
+ int limit_pids = proc_fs_limit_pids(fs_info);
tgid = name_to_int(&dentry->d_name);
if (tgid == ~0U)
@@ -3162,7 +3163,15 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsign
if (!task)
goto out;
+ /* Limit procfs to only ptracable tasks */
+ if (limit_pids == PROC_LIMIT_PIDS_PTRACE) {
+ cond_resched();
+ if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
+ goto out_put_task;
+ }
+
result = proc_pid_instantiate(dir, dentry, task, NULL);
+out_put_task:
put_task_struct(task);
out:
return ERR_PTR(result);
--
2.10.2
--
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next prev parent reply other threads:[~2017-04-25 12:23 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-25 12:23 [PATCH RFC v2 0/6] proc: support private proc instances per pidnamespace Djalal Harouni
2017-04-25 12:23 ` [PATCH RFC v2 1/6] proc: add proc_fs_info struct to store proc information Djalal Harouni
2017-04-25 12:23 ` [PATCH RFC v2 2/6] proc: move /proc/{self|thread-self} dentries to proc_fs_info Djalal Harouni
2017-04-25 12:23 ` [PATCH RFC v2 3/6] proc: add helpers to set and get proc hidepid and gid mount options Djalal Harouni
2017-04-25 12:23 ` [PATCH RFC v2 4/6] proc: support mounting private procfs instances inside same pid namespace Djalal Harouni
2017-04-26 22:13 ` Andy Lutomirski
2017-05-02 14:29 ` Djalal Harouni
2017-05-02 16:33 ` Andy Lutomirski
2017-05-03 15:18 ` Djalal Harouni
2017-04-25 12:23 ` Djalal Harouni [this message]
2017-04-26 22:09 ` [PATCH RFC v2 5/6] proc: instantiate only pids that we can ptrace on 'limit_pids=1' mount option Andy Lutomirski
2017-05-02 14:00 ` Djalal Harouni
2017-04-25 12:23 ` [PATCH RFC v2 6/6] proc: flush task dcache entries from all procfs instances Djalal Harouni
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