Re: [PATCH 5.15.y, 5.10.y] exfat: fix potential deadlock on __exfat_get_dentry_set

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Dec 15, 2024 at 03:11:16AM +0530, Harshit Mogalapalli wrote:
> Hi Greg,
> 
> On 14/12/24 23:36, Greg KH wrote:
> > On Sat, Dec 14, 2024 at 05:57:01PM +0000, Sherry Yang wrote:
> > > Hi,
> > > 
> > > > On Dec 14, 2024, at 6:26 AM, Sasha Levin <sashal@kernel.org> wrote:
> > > > 
> > > > [ Sasha's backport helper bot ]
> > > > 
> > > > Hi,
> > > > 
> > > > The upstream commit SHA1 provided is correct: 89fc548767a2155231128cb98726d6d2ea1256c9
> > > > 
> > > > WARNING: Author mismatch between patch and upstream commit:
> > > > Backport author: Sherry Yang <sherry.yang@oracle.com>
> > > > Commit author: Sungjong Seo <sj1557.seo@samsung.com>
> > > > 
> > > > 
> > > > Status in newer kernel trees:
> > > > 6.12.y | Present (exact SHA1)
> > > > 6.6.y | Present (different SHA1: a7ac198f8dba)
> > > > 6.1.y | Not found
> > > > 5.15.y | Not found
> > > 
> > > I didn’t backport the commit to linux-stable-6.1.y, because 6.1.y didn’t backport the culprit commit
> > > a3ff29a95fde ("exfat: support dynamic allocate bh for exfat_entry_set_cache”), so not influenced.
> > > 
> > > However, both linux-stable-5.15.y and linux-stable-5.10.y actually backported the culprit commit. So I’m trying to fix it on 5.15.y and 5.10.y.
> > > 
> > > Let me know if you have more questions about it.
> > 
> > That's confusing, why doesn't 6.1.y have that commit?  Shouldn't we also
> > add it there along with this one?
> > 
> 
> https://lore.kernel.org/all/20230809103650.353831735@linuxfoundation.org/#t
> 
> Commit a3ff29a95fde ("exfat: support dynamic allocate bh for
> exfat_entry_set_cache”) which is present in 5.10.y and 5.15.y but not in
> 6.1.y is added as a stable-dependency "Stable-dep-of: d42334578eba ("exfat:
> check if filename entries exceeds max filename length") ", but
> this(d42334578eba - filename length check) is present in 6.1.y without
> commit a3ff29a95fde , so probably stable-dep-of is not accurate.
> 
> Given that now we already have a3ff29a95fde ("exfat: support dynamic
> allocate bh for exfat_entry_set_cache”) to 5.15.y and 5.10.y, I think we
> should add it and the fix to 6.1.y as well.
> 
> For 6.1.y here are the upstream commits: (Starting from 1 -- cleanly applies
> and builds fine, haven't done any exfat related testing though.)
> 1. a3ff29a95fde ("exfat: support dynamic allocate bh for
> exfat_entry_set_cache”)
> 2. commit: 89fc548767a2 ("exfat: fix potential deadlock on
> __exfat_get_dentry_set")
> 
> Let me know if you want me to send two patches instead, I can do that.

Yes, please do!

thanks,

greg k-h