Note the proposed solution to protect sensitive procfs entries as
code comment.

Cc: Kees Cook <keesc...@chromium.org>
Suggested-by: Eric W. Biederman <ebied...@xmission.com>
Signed-off-by: Djalal Harouni <tix...@opendz.org>
---
 fs/proc/base.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/proc/base.c b/fs/proc/base.c
index c29eeae..8d21316 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -102,6 +102,17 @@
  *
  *     The classic example of a problem is opening file descriptors
  *     in /proc for a task before it execs a suid executable.
+ *
+ * Solution for sensitive files:
+ *     At each system call: open(),read(),write()... Perform the
+ *     ptrace_may_access() check.
+ *
+ *     After open() and during each system call: read(),write()...
+ *     If the cred of current have changed then perform the
+ *     proc_allow_access() check after the ptrace_may_access() one.
+ *
+ *     This way we can determine if current has gained more privileges
+ *     by execs a suid executable.
  */
 
 struct pid_entry {
-- 
1.7.11.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to