From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DD47835BDB4; Wed, 3 Dec 2025 16:42:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764780123; cv=none; b=DQyJzpSEU0s6azjIo6kiGahOdt9Lr0p0KHAAvIQQazSGJxI5PrNMEO26JBtUr8U2RnpuaFIFL+hr2irff+ScOHmDbxBRgOthA1yXsAr66vyc0vasc66Tgt+EeGSCgwMTHm94RXIj3gxE7IVonmM7oxXNSJITS1VVjord8Dd2i5s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764780123; c=relaxed/simple; bh=WhY7CBnZjYt09WFMw+lNzb0XTWJTaC+aKhXZKz0+XT8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bG8/soy50Kt0Q5hMeh4Bwn3oVmgPyZloriU05ha+M2HcWbghTkeS8q+/V+30iPVKDJM+nEUBRlSghEL4hXlOKQp7pzIPDykw60GEr+rms7n2T7CjsX2cMYaPoxQRwcOMUBnMJc+JI1KM5FMTxZ4BHZdn/yi+hL1rgLOg/oBfwxk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MAaBLspU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MAaBLspU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 217BAC4CEF5; Wed, 3 Dec 2025 16:42:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1764780122; bh=WhY7CBnZjYt09WFMw+lNzb0XTWJTaC+aKhXZKz0+XT8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MAaBLspUjTQ+VLkvWCPvXjewzIUi21PxneBySmznnqgk+UW6jp7ZNSLm1XI3A9EdD aMES6rFnFnN1RAGRXzGD+lJUz8jv7DAYHDJDEPGA9qUJGNhYolLAXB29aT6f0DNScU 3gmB9PlJXZDDgBN0XBC9837DbG0S5R+RcMqf5Qv8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Miquel Raynal Subject: [PATCH 6.1 430/568] mtdchar: fix integer overflow in read/write ioctls Date: Wed, 3 Dec 2025 16:27:12 +0100 Message-ID: <20251203152456.443761474@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251203152440.645416925@linuxfoundation.org> References: <20251203152440.645416925@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit e4185bed738da755b191aa3f2e16e8b48450e1b8 upstream. The "req.start" and "req.len" variables are u64 values that come from the user at the start of the function. We mask away the high 32 bits of "req.len" so that's capped at U32_MAX but the "req.start" variable can go up to U64_MAX which means that the addition can still integer overflow. Use check_add_overflow() to fix this bug. Fixes: 095bb6e44eb1 ("mtdchar: add MEMREAD ioctl") Fixes: 6420ac0af95d ("mtdchar: prevent unbounded allocation in MEMWRITE ioctl") Cc: stable@vger.kernel.org Signed-off-by: Dan Carpenter Signed-off-by: Miquel Raynal Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/mtdchar.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -599,6 +599,7 @@ mtdchar_write_ioctl(struct mtd_info *mtd uint8_t *datbuf = NULL, *oobbuf = NULL; size_t datbuf_len, oobbuf_len; int ret = 0; + u64 end; if (copy_from_user(&req, argp, sizeof(req))) return -EFAULT; @@ -618,7 +619,7 @@ mtdchar_write_ioctl(struct mtd_info *mtd req.len &= 0xffffffff; req.ooblen &= 0xffffffff; - if (req.start + req.len > mtd->size) + if (check_add_overflow(req.start, req.len, &end) || end > mtd->size) return -EINVAL; datbuf_len = min_t(size_t, req.len, mtd->erasesize); @@ -698,6 +699,7 @@ mtdchar_read_ioctl(struct mtd_info *mtd, size_t datbuf_len, oobbuf_len; size_t orig_len, orig_ooblen; int ret = 0; + u64 end; if (copy_from_user(&req, argp, sizeof(req))) return -EFAULT; @@ -724,7 +726,7 @@ mtdchar_read_ioctl(struct mtd_info *mtd, req.len &= 0xffffffff; req.ooblen &= 0xffffffff; - if (req.start + req.len > mtd->size) { + if (check_add_overflow(req.start, req.len, &end) || end > mtd->size) { ret = -EINVAL; goto out; }