From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 2DAE52F21 for ; Mon, 7 Feb 2022 10:30:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644229852; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3cyRyCr5+eamib5wZIABy4k0pAM0GRsoTKR73ge8vW8=; b=afUnP9BF1TqjnNoVdkoIiwLZFdS2Evmm8ctpNdgG9FP7GhTeppliY6xcXPcIaIHD7NYGqW aBGFAQztMNWgWQFjPVoWyBCooa5KWfIerYpuB0kjj2HYC29QUWAA/gKfRt93uZ7AE3t+qZ 9WHunOaafFevTRqQ+Qp3GhMNI+v+r8M= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-253-UDBsiRaoM2S6ps60GOiWsQ-1; Mon, 07 Feb 2022 05:30:48 -0500 X-MC-Unique: UDBsiRaoM2S6ps60GOiWsQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 209C21800D50; Mon, 7 Feb 2022 10:30:47 +0000 (UTC) Received: from work (unknown [10.40.194.180]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DE8AE7D704; Mon, 7 Feb 2022 10:30:12 +0000 (UTC) Date: Mon, 7 Feb 2022 11:30:09 +0100 From: Lukas Czerner To: syzbot Cc: 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 Subject: Re: [syzbot] general protection fault in ext4_fill_super Message-ID: <20220207103009.id72sr4dtghgzp5f@work> References: <0000000000001e0ba105d5c2dede@google.com> <000000000000fbf22d05d74d08fb@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000fbf22d05d74d08fb@google.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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 Thanks! -Lukas