This is a note to let you know that I've just added the patch titled
proc: restrict access to /proc/PID/io
to the 2.6.39-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
proc-restrict-access-to-proc-pid-io.patch
and it can be found in the queue-2.6.39 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 1d1221f375c94ef961ba8574ac4f85c8870ddd51 Mon Sep 17 00:00:00 2001
From: Vasiliy Kulikov <[email protected]>
Date: Fri, 24 Jun 2011 16:08:38 +0400
Subject: proc: restrict access to /proc/PID/io
From: Vasiliy Kulikov <[email protected]>
commit 1d1221f375c94ef961ba8574ac4f85c8870ddd51 upstream.
/proc/PID/io may be used for gathering private information. E.g. for
openssh and vsftpd daemons wchars/rchars may be used to learn the
precise password length. Restrict it to processes being able to ptrace
the target process.
ptrace_may_access() is needed to prevent keeping open file descriptor of
"io" file, executing setuid binary and gathering io information of the
setuid'ed process.
Signed-off-by: Vasiliy Kulikov <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/proc/base.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2762,6 +2762,9 @@ static int do_io_accounting(struct task_
struct task_io_accounting acct = task->ioac;
unsigned long flags;
+ if (!ptrace_may_access(task, PTRACE_MODE_READ))
+ return -EACCES;
+
if (whole && lock_task_sighand(task, &flags)) {
struct task_struct *t = task;
@@ -2892,7 +2895,7 @@ static const struct pid_entry tgid_base_
REG("coredump_filter", S_IRUGO|S_IWUSR,
proc_coredump_filter_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
- INF("io", S_IRUGO, proc_tgid_io_accounting),
+ INF("io", S_IRUSR, proc_tgid_io_accounting),
#endif
};
@@ -3230,7 +3233,7 @@ static const struct pid_entry tid_base_s
REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
- INF("io", S_IRUGO, proc_tid_io_accounting),
+ INF("io", S_IRUSR, proc_tid_io_accounting),
#endif
};
Patches currently in stable-queue which might be from [email protected] are
_______________________________________________
stable mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/stable
