Re: [PATCH 4.19 1/1] ida: Fix crash in ida_free when the bitmap is empty

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Aug 30, 2024 at 10:29:55AM +0200, hsimeliere.opensource@witekio.com wrote:
> From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
> 
> commit af73483f4e8b6f5c68c9aa63257bdd929a9c194a upstream.
> 
> The IDA usually detects double-frees, but that detection failed to
> consider the case when there are no nearby IDs allocated and so we have a
> NULL bitmap rather than simply having a clear bit.  Add some tests to the
> test-suite to be sure we don't inadvertently reintroduce this problem.
> Unfortunately they're quite noisy so include a message to disregard
> the warnings.
> 
> Reported-by: Zhenghan Wang <wzhmmmmm@gmail.com>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Hugo SIMELIERE <hsimeliere.opensource@witekio.com>
> ---
>  lib/idr.c      |  2 +-
>  lib/test_ida.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+), 1 deletion(-)
> 

Now queued up, thanks.

greg k-h