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 4A66D15C82 for ; Mon, 5 Dec 2022 19:19:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A62C7C433D6; Mon, 5 Dec 2022 19:19:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670267977; bh=SaEUP+A35OcIOCecppl5YQ4ap+r1nCvCbkjV+AFi1as=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jRg0Iqix8mDwK/h7DcyVp/G96OoVZXgtJrw3mbM1fd1LGLxDg2Ni7sgByLvOAkkZW q4WK9ClRbFOiYujffJnbeIZLf4Rgkrtx3TPdFmRC9ql+caZQieXjP28CIg4pFK6lPu bCLRYl52+JaLL+QVOnRg1HuBArE4xX5w45mjcscA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiubo Li , Ilya Dryomov , Sasha Levin Subject: [PATCH 4.19 042/105] ceph: avoid putting the realm twice when decoding snaps fails Date: Mon, 5 Dec 2022 20:09:14 +0100 Message-Id: <20221205190804.560343952@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190803.124472741@linuxfoundation.org> References: <20221205190803.124472741@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: Xiubo Li [ Upstream commit 51884d153f7ec85e18d607b2467820a90e0f4359 ] When decoding the snaps fails it maybe leaving the 'first_realm' and 'realm' pointing to the same snaprealm memory. And then it'll put it twice and could cause random use-after-free, BUG_ON, etc issues. Cc: stable@vger.kernel.org Link: https://tracker.ceph.com/issues/57686 Signed-off-by: Xiubo Li Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/snap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 642040beef91..a5ef8275440d 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -671,7 +671,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, struct ceph_mds_snap_realm *ri; /* encoded */ __le64 *snaps; /* encoded */ __le64 *prior_parent_snaps; /* encoded */ - struct ceph_snap_realm *realm = NULL; + struct ceph_snap_realm *realm; struct ceph_snap_realm *first_realm = NULL; struct ceph_snap_realm *realm_to_rebuild = NULL; int rebuild_snapcs; @@ -680,6 +680,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, dout("update_snap_trace deletion=%d\n", deletion); more: + realm = NULL; rebuild_snapcs = 0; ceph_decode_need(&p, e, sizeof(*ri), bad); ri = p; -- 2.35.1