From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=61.135.153.163 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792890113; b=KJ8aUPqweyWqZ7XAE6xDcQZ+DfFfRXlqS9PFqro6zamrC+WkwCvOCWMJJ18v7Z8gAVEp kV0jLUIO7aO5d+QB6VuXPJHR7MUvwWNuVPJrTGSXhpt+0OM6LTmxd87MulljD/JNne7Pe UJfx2A9/NpZU4AhUStl2jAh3oeMMqUIrUIPuJsMm5Wn98JpvBVh6Wg3tho82+YKOZ0D2P lS6LdRy0lBiwSPloFxrsotFoFK7BN88sfBHkWID4sTJZllhEn/CZSJl2afcb8tRud5UBQ c14jL6AhkX96e1LO73qHpGaTOOa/ZdLFJYO/e99SDHhcbCdyy+ZWf4vrnGxSq0tlHgA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792890113; h=DMARC-Filter:DKIM-Signature:X-SMAIL-HELO:Received:X-Sender:X-Auth-ID: X-SMAIL-MID:X-SMAIL-UIID:From:To:Cc:Subject:Date:Message-ID: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=yqTKmgmP2zf6EFfDClO8G04+2/dJbqhXtznY2IQAftg=; b=eGq6hPdqyk4MG+pPHwEOu42+Mrt31CM4xqONdtihz4SeS2OKAmZXkoLW0zL+AaaTIMs/ iydxfQoApoxgnwYpmdKqlsSQNqq7a+7GJ1HK5xysXLWeSMNkmyoilxMxTNTNmQU8htMfA PZ8lnOqXo4UAsW/RGGmOitFkAfpnZxbpKlUejDjYCv1F7OQMzEJQbf1NYm/fA9ONfBdAM a2b2dEAjHcVnJrU2E6Ju8+2wph/PWIkczWhH6Hx4AMHkVsv+odVeY83RocAf1zyytHFyT TUNMJNd7dZBvZBi8wRhKd5x+jUToOCM9m5Bxhnvk8o25SZFhsQbqZP0bAysvum2rrvQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass header.d=sina.com header.i=@sina.com header.a=rsa-sha256 header.s=201208 header.b="pcwd5t1/"; arc=none smtp.remote-ip=61.135.153.163 Received: from smtp153-163.sina.com.cn (smtp153-163.sina.com.cn [61.135.153.163]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4219E606A31B for ; Sun, 25 Oct 2026 01:01:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 4219E606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=sina.com header.i=@sina.com header.a=rsa-sha256 header.s=201208 header.b=pcwd5t1/ DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1792890108; bh=yqTKmgmP2zf6EFfDClO8G04+2/dJbqhXtznY2IQAftg=; h=From:Subject:Date:Message-ID; b=pcwd5t1/e4F8o+CKu0hyyE/G8ncSE8fEATNh+BBD7pFAnYqT0xLf5XGBvdVTgez6t CIeT0f3hpCCdtTAKkk6Phm2xPBu1O0OtDC102P59iFTNjYKIohVHa+xjj+kakKwol9 17LsbJuW+q0viu4WK2AaC3qFPRpjoEIUFBQEsR+k= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.254.1.249]) by sina.com (10.54.253.32) with ESMTP id 6ADD54EF00003890; Sun, 25 Oct 2026 09:01:38 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 8697174456657 X-SMAIL-UIID: FB151329637B45088D635C168D864685-20261025-090138-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [dm?] KASAN: slab-use-after-free Read in snapshot_ctr Date: Sun, 25 Oct 2026 09:01:24 +0800 Message-ID: <20261025010125.1085-1-hdanton@sina.com> In-Reply-To: <6adcd395.998fdb85.f0000.0011.GAE@google.com> References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > Date: Sat, 24 Oct 2026 08:49:41 -0700 [thread overview] > Hello, > > syzbot found the following issue on: > > HEAD commit: f47d223627f8 Merge tag 'vfs-7.4-rc1.sync_close' of git://g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=127202a5580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=97e47414c855a3d8 > dashboard link: https://syzkaller.appspot.com/bug?extid=8e6fc64255334ccf3ab3 > compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16a47f71580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13edba35580000 #syz test: upstream f47d223627f8 --- x/drivers/md/dm-table.c +++ y/drivers/md/dm-table.c @@ -400,8 +400,8 @@ int dm_get_device(struct dm_target *ti, if (r) return r; } - refcount_inc(&dd->count); out: + refcount_inc(&dd->count); *result = dd->dm_dev; return 0; } --- x/drivers/md/dm-snap.c +++ y/drivers/md/dm-snap.c @@ -1390,6 +1390,7 @@ static int snapshot_ctr(struct dm_target if (r) goto bad_read_metadata; + dm_put_device(ti, s->cow); return 0; bad_read_metadata: --