Re: [PATCH] vfs: Don't leak a path when get_empty_filp in dentry_open

From: Eric W. Biederman
Date: Thu Jan 16 2014 - 19:17:40 EST


Al Viro <viro@xxxxxxxxxxxxxxxxxx> writes:

> On Thu, Jan 16, 2014 at 03:45:38PM -0800, Eric W. Biederman wrote:
>>
>> Normally in dentry_open the passed in path is placed on the new filp
>> removing the caller from needing to worry about it. In the rare case
>> that we can not allocate a filp the path is not consumed. None of the
>> callers of dentry_open call path_put in their error handling when
>> dentry_open fails so call path_put for them on error and keep everyone's
>> error handling simple.
>
> You are misreading that code. _No_ path in dentry_open() drops that
> sucker, no matter whether we succeed or fail. do_dentry_open() grabs
> an extra reference on success, so those fput() on other failure exits
> just balance that.

Yep you are right. My mistake. The weird code flow tricked me.

Eric
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