Bug#1115729: Stable fix request: error in internal cancellation syscall handling, corrupting copy_file_range syscall return value

Quoting Aurelien Jarno (2025-11-16 14:29:12)
> On 2025-11-16 04:51, Daniel Shahaf wrote:
> > Joel Johnson wrote on Fri, Sep 19, 2025 at 08:45:10 -0600:
> > > Package: libc
> > > Version: 2.41-12
> > > Severity: grave
> > > 
> > > (Marking as grave since it leads to data loss)
> > > 
> > > An issue has been identified and fixed upstream causing data loss using
> > > copy_file_range. It is most prominent with OpenZFS but also appears to have
> > > potential impacts on FUSE. I would request that this be patched for a trixie
> > > update. I didn't see any existing issue for this, apologies if it's a
> > > duplicate.
> > > 
> > > https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=7107bebf19286f42dcb0a97581137a5893c16206
> > > 
> > > https://sourceware.org/bugzilla/show_bug.cgi?id=33245
> > > 
> > > https://debbugs.gnu.org/cgi/bugreport.cgi?bug=79139
> > 
> > Morning.  I haven't run into the buggy behaviour, but I did run into
> > this ticket in the apt-listchanges(1) output during an upgrade, and I'm
> > not sure whether the bug would impact me if I proceeded with the upgrade.
> > 
> > Two questions:
> > 
> > 1. Considering this bug is described as "data loss" and appears in
> >    apt-listchanges(1) output for folks upgrading oldstable→stable, could
> >    someone please summarize situations in which the bug is known /not/
> >    to occur even under 2.41-12 (currently in trixie)?
> >    
> >    I'm not asking for an exhaustive list; just for common known-good
> >    scenarios.  Something of the form "It's safe to upgrade to trixie and
> >    glibc/2.41-12 as long as you don't do X, Y, or Z" would be great.
> 
> The bugs does not appear with usual filesystems like ext4 or xfs.
> 
> > 2. The bug is fixed in 2.41-2 in experimental, but hasn't yet been fixed
> 
> Actually in 2.42-2.
> 
> >    in either sid or trixie (as requested by the OP).  Is the bug
> >    expected to be fixed in trixie?
> 
> Yes, this is planned, but it has to be fixed before being able to fix 
> it in trixie.
> 
> >    I'm not sure what blocks 2.42 from being uploaded to sid.
> 
> The plan was indeed to stop the maintenance of 2.41 in sid and upload 
> 2.42 to sid. A lot of effort has been put on preparing 2.42, including 
> an archive rebuild. Unfortunately this is currently blocked by #1115881 
> with no answer from the Ada maintainers...
> 
> After that I lost all my motivation to work on glibc. I guess, I'll try 
> to upload a new 2.41 version to sid, so that we can fix the bug in 
> trixie...

I am sorry to hear that, I hope your motivation recovered now that 2.42 is in
testing!

Is there anything I can do to help get a fixed 2.41 into 13.4 (preparing the
update, testing it, filing p-u, ..)?

Regards,
Fabian