Re: [PATCH v4 0/5] Improve simple directory offset wrap behavior

[Chuck Lever <chuck.lever@oracle.com>]

On 12/4/24 10:52 AM, cel@kernel.org wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> The purpose of this series is to construct a set of upstream fixes
> that can be backported to v6.6 to address CVE-2024-46701.
> 
> My original plan was to add a cursor dentry. However, I've found a
> solution that does not need one. In fact, most or all of the
> reported issues are gone with 4/5. Thus I'm not sure 5/5 is
> necessary, but it seems like a robust improvement.
> 
> Changes since v3:
> - Series is no longer RFC
> - Series passes xfstests locally and via NFS export
> - Patch 2/5 was replaced; it now removes simple_offset_empty()
> - 4/5 and 5/5 were rewritten based on test results
> - Patch descriptions have been clarified
> 
> This series (still against v6.12) has been pushed to:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/log/?h=tmpfs-fixes
> 
> Next step is to try backporting these to v6.6 to see if anything
> else is needed.
> 
> Chuck Lever (5):
>    libfs: Return ENOSPC when the directory offset range is exhausted
>    Revert "libfs: Add simple_offset_empty()"
>    Revert "libfs: fix infinite directory reads for offset dir"
>    libfs: Replace simple_offset end-of-directory detection
>    libfs: Use d_children list to iterate simple_offset directories
> 
>   fs/libfs.c         | 158 ++++++++++++++++++++++-----------------------
>   include/linux/fs.h |   1 -
>   mm/shmem.c         |   4 +-
>   3 files changed, 81 insertions(+), 82 deletions(-)
> 

I've backported these, as a proof of concept, to origin/linux-6.6.y. You
can find that here:

https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/log/?h=nfsd-6.6.y

This series passes xfstests, including generic/736.

It would be a little cleaner if I could also backport da549bdd15c2
("dentry: switch the lists of children to hlist"), but that has similar
risks as backporting the Maple tree patches.


-- 
Chuck Lever