Re: [PATCH 1/2] audit: don't free_chunk() after fsnotify_add_mark()

From: Miklos Szeredi
Date: Fri Aug 03 2012 - 06:23:00 EST


Miklos Szeredi <miklos@xxxxxxxxxx> writes:

> Al, your are the co-maintainer of audit, right? Can you please apply
> these patches as Eric is on vaction.

Eric, Al,

Can you please apply these two bugfix patches for audit?

Thanks,
Miklos


> From: Miklos Szeredi <mszeredi@xxxxxxx>
>
> Don't do free_chunk() after fsnotify_add_mark(). That one does a delayed unref
> via the destroy list and this results in use-after-free.
>
> Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
> Acked-by: Eric Paris <eparis@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> ---
> kernel/audit_tree.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> Index: linux-2.6/kernel/audit_tree.c
> ===================================================================
> --- linux-2.6.orig/kernel/audit_tree.c 2011-10-26 14:26:24.000000000 +0200
> +++ linux-2.6/kernel/audit_tree.c 2012-05-30 16:56:04.000000000 +0200
> @@ -259,7 +259,7 @@ static void untag_chunk(struct node *p)
>
> fsnotify_duplicate_mark(&new->mark, entry);
> if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, NULL, 1)) {
> - free_chunk(new);
> + fsnotify_put_mark(&new->mark);
> goto Fallback;
> }
>
> @@ -322,7 +322,7 @@ static int create_chunk(struct inode *in
>
> entry = &chunk->mark;
> if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
> - free_chunk(chunk);
> + fsnotify_put_mark(entry);
> return -ENOSPC;
> }
>
> @@ -396,7 +396,7 @@ static int tag_chunk(struct inode *inode
> fsnotify_duplicate_mark(chunk_entry, old_entry);
> if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, NULL, 1)) {
> spin_unlock(&old_entry->lock);
> - free_chunk(chunk);
> + fsnotify_put_mark(chunk_entry);
> fsnotify_put_mark(old_entry);
> return -ENOSPC;
> }
--
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