From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f53.google.com (mail-oo1-f53.google.com [209.85.161.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A89232F21 for ; Mon, 7 Feb 2022 11:29:42 +0000 (UTC) Received: by mail-oo1-f53.google.com with SMTP id t75-20020a4a3e4e000000b002e9c0821d78so13268679oot.4 for ; Mon, 07 Feb 2022 03:29:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GdrAEtpSp9knE3dG4N9tmiah7mkkROzWWe9VwwtgIEE=; b=hm9BqMPBVXryDOYxjtgkzshKUBUyISC+PQUo9JZc0hU2pX+klK/9GoBimwmV4SbPbs Cqktu28LyobNhdW4hSKY5KtDI2UWmSNcgeBjPTEd7B4KB0hv2NV+qWzvuHN6+SkOtFu5 TiwDUyoGDQxMO8KHFSZQJ2fIbs8XY6z6xtTOFXXwph0LDKis4tf2aBVt2bTqxORAi41k 0mvxrR6ZwQGJIQ4JCZ1rPHseamYb5bXnm/00ermwgNFOxidmOYZNjcSWxwjAfipHHjP3 5kb+IMCddLCjqQ0SjILaVak/wEXI3KPC55ZNGDUEu9H22th2mZrQCZFD6FlRu9EAsZ9l NCiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GdrAEtpSp9knE3dG4N9tmiah7mkkROzWWe9VwwtgIEE=; b=FWd4C38QiJsR1Cufo1aVEe+yd8tPoTDoqROnivCXLU+yJH9jnoMxydXBDKrvkNASPl VOmoMLgP15ANgiPrDoDuwKW9EjHKhY1ZKV5WaVBVUhLK0VbHM/l1rxszSYh20v27i3nT zY2i+vdIJ46clEsgbNdU93PBDRpU7efxjK0vauhu/U6XpGKP3lEndXwETuLn65afknrY K0ckzU2jpwa+OJnhbp9DCM6XJI6jbbynHckSD/4oyQ2NvtJKVBp46CeEtmJ9kqwyOPUO DTpJJxksn1T114ET4vQYXkIQ75x1156TNF7g2eHPuvRpQlS1wqa+nuEOfRLGs3BpwPb8 hW3Q== X-Gm-Message-State: AOAM531givrBaRxbg5i/lGXjfb2tjguNKolMAUszGiSAmTU6TA9n0ShL u3i1ixXBn2YbcMeknIciAnFWuB26DOCXn7ZJfpUpxg== X-Google-Smtp-Source: ABdhPJyznrMFFiZoDqOMDlGRTRqArtq67oollYysU5ym1cWQLUvuAwYKu1pUfSpdvfjbXzTs/4WO2obpDRUITFEc+0s= X-Received: by 2002:a05:6870:7715:: with SMTP id dw21mr3643420oab.38.1644233381454; Mon, 07 Feb 2022 03:29:41 -0800 (PST) Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <0000000000001e0ba105d5c2dede@google.com> <000000000000fbf22d05d74d08fb@google.com> <20220207103009.id72sr4dtghgzp5f@work> In-Reply-To: <20220207103009.id72sr4dtghgzp5f@work> From: Dmitry Vyukov Date: Mon, 7 Feb 2022 12:29:30 +0100 Message-ID: Subject: Re: [syzbot] general protection fault in ext4_fill_super To: Lukas Czerner Cc: syzbot , adilger.kernel@dilger.ca, cmaiolino@redhat.com, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, nathan@kernel.org, ndesaulniers@google.com, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8" On Mon, 7 Feb 2022 at 11:30, Lukas Czerner wrote: > > On Sat, Feb 05, 2022 at 02:39:06PM -0800, syzbot wrote: > > syzbot has bisected this issue to: > > > > commit cebe85d570cf84804e848332d6721bc9e5300e07 > > Author: Lukas Czerner > > Date: Wed Oct 27 14:18:56 2021 +0000 > > > > ext4: switch to the new mount api > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14902978700000 > > start commit: 0457e5153e0e Merge tag 'for-linus' of git://git.kernel.org.. > > git tree: upstream > > final oops: https://syzkaller.appspot.com/x/report.txt?x=16902978700000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=12902978700000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=cd57c0f940a9a1ec > > dashboard link: https://syzkaller.appspot.com/bug?extid=138c9e58e3cb22eae3b4 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17f7004fb00000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cf108700000 > > > > Reported-by: syzbot+138c9e58e3cb22eae3b4@syzkaller.appspotmail.com > > Fixes: cebe85d570cf ("ext4: switch to the new mount api") > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > > > I believe that this has been fixed with upstream commit > > commit 7c268d4ce2d3761f666a9950b029c8902bfab710 > Author: Lukas Czerner > Date: Wed Jan 19 14:02:09 2022 +0100 > > ext4: fix potential NULL pointer dereference in ext4_fill_super() > > By mistake we fail to return an error from ext4_fill_super() in case > that ext4_alloc_sbi() fails to allocate a new sbi. Instead we just set > the ret variable and allow the function to continue which will later > lead to a NULL pointer dereference. Fix it by returning -ENOMEM in the > case ext4_alloc_sbi() fails. > > Fixes: cebe85d570cf ("ext4: switch to the new mount api") > Reported-by: kernel test robot > Reported-by: Dan Carpenter > Signed-off-by: Lukas Czerner > Link: https://lore.kernel.org/r/20220119130209.40112-1-lczerner@redhat.com > Signed-off-by: Theodore Ts'o > Cc: stable@kernel.org Let's tell syzbot then: #syz fix: ext4: fix potential NULL pointer dereference in ext4_fill_super() Thanks