From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9E7812135A5; Thu, 20 Feb 2025 16:15:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740068158; cv=none; b=neEZ9dw6RYOnG7dA1fIhzckzN8HmPxH90PuMfGyF2QfcRgWcfA4fC2VUgyILe/PSxDfvQ4ezMo2VksDQN2DCt8VvBQegoXHNUpZ+YwAiwIuDSEYweYy/ODj3cE20YDehJYhDG1p26Ulr/j6qVF0CG0scJLFbDpfXFgg2Ezahb7o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740068158; c=relaxed/simple; bh=v5jU51XdS5IxHtGzZ0jSCWi4nb+5lghXAbNiqz17AXo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MXpidfhOqiK1jrhH7EljeAZnvP7Ift89wlE2XpFTXdYFp71TnlUrNcbErWmb/pw+sSQl+vb6xqy3i19txyxWdhKlv/omhmmjg3O2d+JJwdgtmLg0XS1Rfp8uxgsvoxjXsK7HJpxbAir5Vy/PjZpzDxwUp8ilG0FaFFQUEc+eAt8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=fSEQdgil; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fSEQdgil" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=/v0e059AYWdCApNiIRf7ofl3oeJFZjMI+2NzL/MN+sA=; b=fSEQdgil+eU5Ey5bdxle+6sEXy 2jGSwL1/1bSyKEksuPVT+RKzowhvqnldQwuTQiIhBtSePe42QjCLkNb67YnEUEaLkAWHrv5Ym6+Vi uDZbZW2W6Q0OfG/HxGypfBxH75KYG+2Jgx3sBR14qG7evqfnJTktW+YVk/rHbzHdHT5qgrlP7nIFa xcx9xU12o+VB08HLU2uHS77KYBiMGbo81IQg6iJ5nRlUpp71aFufA9bo+IjJmmDavrDyoPs3s+Gv7 U11z9Yqkp3aldNMLrewhuDPZFZ5V4HqubXHWuRkF3yvV9XMEWVg4Bm5PcAHu3naXNQMmd0m9P2aL0 iZEmNnqQ==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tl9DN-0000000A9dX-408l; Thu, 20 Feb 2025 16:15:53 +0000 Date: Thu, 20 Feb 2025 16:15:53 +0000 From: Matthew Wilcox To: syzbot Cc: Dominique Martinet , v9fs@lists.linux.dev, dhowells@redhat.com, jlayton@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, netfs@lists.linux.dev, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [netfs?] kernel BUG in folio_unlock (3) Message-ID: References: <67b75198.050a0220.14d86d.02e2.GAE@google.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <67b75198.050a0220.14d86d.02e2.GAE@google.com> On Thu, Feb 20, 2025 at 08:00:24AM -0800, syzbot wrote: > ------------[ cut here ]------------ > kernel BUG at mm/filemap.c:1499! Tried to unlock a folio that wasn't locked. The entire log is interesting: https://syzkaller.appspot.com/x/log.txt?x=12af2fdf980000 It injects a failure which hits p9_tag_alloc() (so adding the 9p people to the cc) The page dump is: page: refcount:1 mapcount:0 mapping:ffff888035b30890 index:0x0 pfn:0x37e9a memcg:ffff88801c6be000 aops:v9fs_addr_operations ino:2721d72 dentry name(?):"file0" flags: 0xfff20000000020(lru|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff20000000020 ffffea0000e1d1c8 ffff88801b0b31a0 ffff888035b30890 raw: 0000000000000000 0000000000000000 00000001ffffffff ffff88801c6be000 page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio)) > Call Trace: > > netfs_perform_write+0xc04/0x2140 fs/netfs/buffered_write.c:400 > netfs_buffered_write_iter_locked fs/netfs/buffered_write.c:445 [inline] > netfs_file_write_iter+0x494/0x550 fs/netfs/buffered_write.c:484 > v9fs_file_write_iter+0x9b/0x100 fs/9p/vfs_file.c:407 > new_sync_write fs/read_write.c:586 [inline] > vfs_write+0x5ae/0x1150 fs/read_write.c:679 > ksys_write+0x12b/0x250 fs/read_write.c:731