From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794050948; b=YMYQPosthUhhUErMHWNqCZPqPvNVpwyikd+l4/jVRmb6Unq8jE6uWmhVvkGfCx/Hjs4/ 5/3XYDcnJcb2YN040B6Lsn37GHt8xMbEOYcRJKhDd/mx5CTQaxC12MVNgKD+PI7+DaxgM AJ7i65gQamQdVBPQmyqOWwTe1yScZR2TuonsAsEF10paIwft0bhM5Z/o3Cd9cbqXPiD2B NoDOrzRpoKdzoCL2KAsa1q7nv6TZe5ktw5SF6z/oqwwnl6uFfCGdtESw8B58UyyoaXE6d BVUJd/TSteMjiodznkyJug4YXpxMIpoqXV4z05HINyu7fucNSRgkpE8/GpPG+rs0zVg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794050948; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=LPCQuNQtkvuPcT3kT7vqEzG8o7EI5UF6IZsSGOLJtOw=; b=eIis2J54I+f9JHheAGZD3blRCh8wopNbk5LDMxhN94YGiE56SVnwJFGrJgyngMXoJfXp PpSC1I0PEFZXDqUs8CC9wHy5thJll0zTcyhSua/PbW5kDIOZTL9d3X/oBbu7YVtVMebeE vDXCuBw745YowQuHkNW5pZgJdDcM6KW1CKvIMBKmb+ntfNpGiUPihD7nBezxxMTRXC8OX KeDctvrq+kFgAipum23b6RUrTpxtt+IIO30BqT71dJw9VjOcESaR8S1Kp5Js3iWMW+u1K Ufb5o0EehYZpOpTkPI7ezp7Pfgy8cU1itmTuzj5UyuDPxkP20/UkXXSPqGsuhy+mlNg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=N3Yrk285; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D710606A32F for ; Sat, 7 Nov 2026 11:29:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=N3Yrk285 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD3051F0089F; Sat, 7 Nov 2026 11:29:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794050948; bh=LPCQuNQtkvuPcT3kT7vqEzG8o7EI5UF6IZsSGOLJtOw=; h=From:To:Cc:Subject:Date; b=N3Yrk285qu2DYXkh/+zW5ULqvHD/sq+8CekOkFJXQmJE64lLL0ToAtMKki32uzCZs TtCtOPINhpcHNPStK09rUORWNqGkDDb0Xa5rArkhACBeru7GYrgTayZhtLib3Lc9vA 6DSq5Ia/jRfyLK6NOZMVzMxa6jbrmJEeztiG2XJVuJy5uTJGPfpJT5Xtk1DERyL0mI prRFyYk1v2/4kmahVFhfEwfklraP5UMPTtJx+RHuPa9snH2x0QzXL14fbCcBHOuQYZ EWThqInaRIwAakVECqOUIl06ughiXCROtkuWr85NPk2v1309rKGY8CFwvOdYqoyQin rheTE1OjD1z9A== From: Sasha Levin To: xmei5@asu.edu, co+ecaada42f806f629@bugs.sh, amarkuze@redhat.com, idryomov@gmail.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] ceph: fix integer overflow in the snap trace bounds check" failed to apply to 5.10-stable tree Date: Sat, 7 Nov 2026 06:29:06 -0500 Message-ID: <20261107062906-failed-5.10-b3bf89767e3c@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x b3bf89767e3ca9506f1c7167cac97c41ec254d42 # git commit -s git send-email --to '' --in-reply-to '20261107062906-failed-5.10-b3bf89767e3c@kernel.org' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From b3bf89767e3ca9506f1c7167cac97c41ec254d42 Mon Sep 17 00:00:00 2001 From: Xiang Mei Date: Tue, 15 Sep 2026 14:40:27 -0700 Subject: [PATCH] ceph: fix integer overflow in the snap trace bounds check ceph_update_snap_trace() bounds the two encoded snapid arrays that follow a struct ceph_mds_snap_realm with sizeof(u64) * (num_snaps + num_prior_parent_snaps). Both counts come straight off the wire as __le32, so the addition is evaluated in unsigned int and wraps before sizeof(u64) promotes it to size_t: an MDS sending num_snaps = 1 and num_prior_parent_snaps = 0xffffffff makes the sum zero and the check degenerates to ceph_decode_need(&p, e, 0, bad), which always passes. dup_array() then reads num_snaps * 8 bytes past the end of the message front, which ceph_msg_new2() allocates at exactly front_len bytes. An unsolicited CEPH_MSG_CLIENT_SNAP reaches this from a malicious or compromised MDS with no client-side action, as do the snaptraces carried in an MDS reply and in a cap import. Compute the length with size_add()/size_mul() so it saturates at SIZE_MAX instead of wrapping, in the style fs/ceph/mdsmap.c already uses for num_export_targets. BUG: KASAN: slab-out-of-bounds in dup_array (include/linux/unaligned.h:28 fs/ceph/snap.c:500) Read of size 8 at addr ffff8880102a16c8 by task kworker/1:2/129 Workqueue: ceph-msgr ceph_con_workfn Call Trace: dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) print_report (mm/kasan/report.c:378 mm/kasan/report.c:482) kasan_report (mm/kasan/report.c:595) dup_array (include/linux/unaligned.h:28 fs/ceph/snap.c:500) ceph_update_snap_trace (fs/ceph/snap.c:836) ceph_handle_snap (fs/ceph/snap.c:1155) mds_dispatch (fs/ceph/mds_client.c:7234) ceph_con_process_message (net/ceph/messenger.c:1424) ceph_con_v1_try_read (net/ceph/messenger_v1.c:1430) ceph_con_workfn (net/ceph/messenger.c:1576) process_one_work (kernel/workqueue.c:3396) worker_thread (kernel/workqueue.c:3479 kernel/workqueue.c:3560) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) ... The buggy address is located 0 bytes to the right of allocated 72-byte region [ffff8880102a1680, ffff8880102a16c8) Cc: stable@vger.kernel.org Fixes: 963b61eb041e ("ceph: snapshot management") Reported-by: co+ecaada42f806f629@bugs.sh Assisted-by: LLM Signed-off-by: Xiang Mei Reviewed-by: Alex Markuze Signed-off-by: Ilya Dryomov --- fs/ceph/snap.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 498ffc1a91cb8..5c1540d95b8c3 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -788,6 +788,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, struct ceph_snap_realm *first_realm = NULL; struct ceph_snap_realm *realm_to_rebuild = NULL; struct ceph_client *client = mdsc->fsc->client; + size_t snaps_len; int rebuild_snapcs; int err = -ENOMEM; int ret; @@ -802,8 +803,10 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, ceph_decode_need(&p, e, sizeof(*ri), bad); ri = p; p += sizeof(*ri); - ceph_decode_need(&p, e, sizeof(u64)*(le32_to_cpu(ri->num_snaps) + - le32_to_cpu(ri->num_prior_parent_snaps)), bad); + snaps_len = size_mul(size_add(le32_to_cpu(ri->num_snaps), + le32_to_cpu(ri->num_prior_parent_snaps)), + sizeof(u64)); + ceph_decode_need(&p, e, snaps_len, bad); snaps = p; p += sizeof(u64) * le32_to_cpu(ri->num_snaps); prior_parent_snaps = p; -- 2.53.0