From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-raid@vger.kernel.org,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>
Subject: Re: [PATCH 05/24] devtmpfs: open code ksys_chdir and ksys_chroot
Date: Tue, 21 Jul 2020 20:26:07 +0200 [thread overview]
Message-ID: <20200721182607.GA14450@lst.de> (raw)
In-Reply-To: <20200721171627.GZ2786714@ZenIV.linux.org.uk>
On Tue, Jul 21, 2020 at 06:16:27PM +0100, Al Viro wrote:
> On Tue, Jul 21, 2020 at 09:49:17AM -0700, Linus Torvalds wrote:
> > On Tue, Jul 21, 2020 at 9:28 AM Christoph Hellwig <hch@lst.de> wrote:
> > >
> > > +
> > > + /* traverse into overmounted root and then chroot to it */
> > > + if (!kern_path("/..", LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path) &&
> > > + !inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR) &&
> > > + ns_capable(current_user_ns(), CAP_SYS_CHROOT) &&
> > > + !security_path_chroot(&path)) {
> > > + set_fs_pwd(current->fs, &path);
> > > + set_fs_root(current->fs, &path);
> > > + }
> > > + path_put(&path);
> >
> > This looks wrong.
>
> It is wrong. kern_path() leaves *path unmodified in case of error, and
> that struct path is uninitialized here.
Yep. Only saving grace is that the error just doesn't happen during
early init.
next prev parent reply other threads:[~2020-07-21 18:26 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 16:27 add file system helpers that take kernel pointers for the init code v2 Christoph Hellwig
2020-07-21 16:27 ` [PATCH 01/24] fs: refactor do_mount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 02/24] fs: refactor ksys_umount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 03/24] fs: push the getname from do_rmdir into the callers Christoph Hellwig
2020-07-21 16:27 ` [PATCH 04/24] devtmpfs: open code do_mount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 05/24] devtmpfs: open code ksys_chdir and ksys_chroot Christoph Hellwig
[not found] ` <20200721162818.197315-6-hch-jcswGhMUV9g@public.gmane.org>
2020-07-21 16:49 ` Linus Torvalds
[not found] ` <CAHk-=wi0GQqAq6VSY=O2iWnPuuS54TkyRBH5B9Ca0Kg5A9d2aA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2020-07-21 17:16 ` Al Viro
2020-07-21 18:26 ` Christoph Hellwig [this message]
2020-07-21 16:28 ` [PATCH 06/24] md: open code vfs_stat in md_setup_drive Christoph Hellwig
[not found] ` <20200721162818.197315-7-hch-jcswGhMUV9g@public.gmane.org>
2020-07-21 16:55 ` Al Viro
[not found] ` <20200721165539.GT2786714-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2020-07-21 18:27 ` Christoph Hellwig
[not found] ` <20200721182701.GB14450-jcswGhMUV9g@public.gmane.org>
2020-07-22 7:44 ` Al Viro
[not found] ` <20200722074432.GD2786714-3bDd1+5oDREiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
2020-07-22 14:05 ` Christoph Hellwig
2020-07-21 16:28 ` [PATCH 07/24] init: initialize ramdisk_execute_command at compile time Christoph Hellwig
2020-07-21 16:28 ` [PATCH 08/24] init: move the prepare_namespace prototype to init/do_mounts.h Christoph Hellwig
2020-07-21 16:28 ` [PATCH 09/24] init: mark create_dev as __init Christoph Hellwig
2020-07-21 16:28 ` [PATCH 10/24] init: open code ksys_umount in handle_initrd Christoph Hellwig
2020-07-21 16:28 ` [PATCH 11/24] init: open code do_utimes in do_utime Christoph Hellwig
[not found] ` <20200721162818.197315-1-hch-jcswGhMUV9g@public.gmane.org>
2020-07-21 16:28 ` [PATCH 12/24] init: add an init_mount helper Christoph Hellwig
2020-07-21 16:58 ` Al Viro
2020-07-21 16:28 ` [PATCH 17/24] init: add an init_chown helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 18/24] init: add an init_chmod helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 20/24] init: add an init_link helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 13/24] init: add an init_unlink helper Christoph Hellwig
[not found] ` <20200721162818.197315-14-hch-jcswGhMUV9g@public.gmane.org>
2020-07-21 17:12 ` Al Viro
2020-07-21 16:28 ` [PATCH 14/24] init: add an init_rmdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 15/24] init: add an init_chdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 16/24] init: add an init_chroot helper Christoph Hellwig
2020-07-21 17:10 ` Al Viro
2020-07-21 16:28 ` [PATCH 19/24] init: add an init_eaccess helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 21/24] init: add an init_symlink helper Christoph Hellwig
2020-07-21 17:00 ` Al Viro
2020-07-21 16:28 ` [PATCH 22/24] init: add an init_mkdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 23/24] init: add an init_mknod helper Christoph Hellwig
2020-07-21 17:02 ` Al Viro
2020-07-21 16:28 ` [PATCH 24/24] init: add an init_lstat helper Christoph Hellwig
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