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 C2DAD847E for ; Fri, 10 Mar 2023 13:52:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 401E2C433D2; Fri, 10 Mar 2023 13:52:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678456326; bh=E43R0iNdn+mVOhgYm4YgbbFq03pcBGhufSJwQRkWytY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hdwYMcr1lU7g2CzMrshw9Zon8r6Ghs1dZ5NFyVKU0i+N26cVWd99mwj0AgqwtfYpj Sx6Z1P8kBlQWa85yTAErFl8aaYZMb1j7oejJVE1nqNGqIceVScF991D+BY/MaPFvW1 rjK8TKfgjUEH0MMQ8BC4w5dQLKemogdMkeOZAHbU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhihao Cheng , Yang Yingliang , Richard Weinberger , Sasha Levin Subject: [PATCH 4.14 158/193] ubi: Fix possible null-ptr-deref in ubi_free_volume() Date: Fri, 10 Mar 2023 14:39:00 +0100 Message-Id: <20230310133716.435991826@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133710.926811681@linuxfoundation.org> References: <20230310133710.926811681@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yang Yingliang [ Upstream commit c15859bfd326c10230f09cb48a17f8a35f190342 ] It willl cause null-ptr-deref in the following case: uif_init() ubi_add_volume() cdev_add() -> if it fails, call kill_volumes() device_register() kill_volumes() -> if ubi_add_volume() fails call this function ubi_free_volume() cdev_del() device_unregister() -> trying to delete a not added device, it causes null-ptr-deref So in ubi_free_volume(), it delete devices whether they are added or not, it will causes null-ptr-deref. Handle the error case whlie calling ubi_add_volume() to fix this problem. If add volume fails, set the corresponding vol to null, so it can not be accessed in kill_volumes() and release the resource in ubi_add_volume() error path. Fixes: 801c135ce73d ("UBI: Unsorted Block Images") Suggested-by: Zhihao Cheng Signed-off-by: Yang Yingliang Reviewed-by: Zhihao Cheng Signed-off-by: Richard Weinberger Signed-off-by: Sasha Levin --- drivers/mtd/ubi/build.c | 1 + drivers/mtd/ubi/vmt.c | 12 ++++++------ 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 211fa2770a4eb..c6765210a6fc8 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -480,6 +480,7 @@ static int uif_init(struct ubi_device *ubi) err = ubi_add_volume(ubi, ubi->volumes[i]); if (err) { ubi_err(ubi, "cannot add volume %d", i); + ubi->volumes[i] = NULL; goto out_volumes; } } diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 26dcffb624e87..8815673e2e57d 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -588,6 +588,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) if (err) { ubi_err(ubi, "cannot add character device for volume %d, error %d", vol_id, err); + vol_release(&vol->dev); return err; } @@ -598,15 +599,14 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) vol->dev.groups = volume_dev_groups; dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id); err = device_register(&vol->dev); - if (err) - goto out_cdev; + if (err) { + cdev_del(&vol->cdev); + put_device(&vol->dev); + return err; + } self_check_volumes(ubi); return err; - -out_cdev: - cdev_del(&vol->cdev); - return err; } /** -- 2.39.2