From: Kirill Korotaev <dev@sw.ru>
To: devel@openvz.org
Cc: akpm@osdl.org, pasky@suse.cz, linux-kernel@vger.kernel.org
Subject: Re: [Devel] [RFC] Allow access to /proc/$PID/fd after setuid()
Date: Thu, 01 Feb 2007 18:16:38 +0300 [thread overview]
Message-ID: <45C20456.2070800@sw.ru> (raw)
In-Reply-To: <20070201150434.GA6023@localhost.sw.ru>
Acked-By: Kirill Korotaev <dev@openvz.org>
> /proc/$PID/fd has r-x------ permissions, so if process does setuid(), it
> will not be able to access /proc/*/fd/. This breaks fstatat() emulation
> in glibc.
>
> open("foo", O_RDONLY|O_DIRECTORY) = 4
> setuid32(65534) = 0
> stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied)
>
> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
> ---
>
> fs/proc/base.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> --- a/fs/proc/base.c
> +++ b/fs/proc/base.c
> @@ -1413,11 +1413,27 @@ static struct file_operations proc_fd_op
> .readdir = proc_readfd,
> };
>
> +static int proc_fd_permission(struct inode *inode, int mask, struct nameidata *nd)
> +{
> + struct task_struct *tsk;
> + int rv;
> +
> + rv = generic_permission(inode, mask, NULL);
> + if (rv == 0)
> + return 0;
> + tsk = get_proc_task(inode);
> + if (tsk == current)
> + rv = 0;
> + put_task_struct(tsk);
> + return rv;
> +}
> +
> /*
> * proc directories can do almost nothing..
> */
> static struct inode_operations proc_fd_inode_operations = {
> .lookup = proc_lookupfd,
> + .permission = proc_fd_permission,
> .setattr = proc_setattr,
> };
>
>
> _______________________________________________
> Devel mailing list
> Devel@openvz.org
> https://openvz.org/mailman/listinfo/devel
>
prev parent reply other threads:[~2007-02-01 15:05 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-01 15:04 [RFC] Allow access to /proc/$PID/fd after setuid() Alexey Dobriyan
2007-02-01 15:16 ` Kirill Korotaev [this message]
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