[ Upstream commit dc60992ce7 ]
When the main loop in xfs_filestream_pick_ag fails to find a suitable
AG it tries to just pick the online AG. But the loop for that uses
args->pag as loop iterator while the later code expects pag to be
set. Fix this by reusing the max_pag case for this last resort, and
also add a check for impossible case of no AG just to make sure that
the uninitialized pag doesn't even escape in theory.
Reported-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com
Fixes: f8f1ed1ab3 ("xfs: return a referenced perag from filestreams allocator")
Cc: <stable@vger.kernel.org> # v6.3
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
77ddc73241