From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0ED233F8883 for ; Thu, 20 Aug 2026 11:12:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787224348; cv=none; b=I9eDVKyG6yA9AsRXL9ijj5cmLfYns6zxHs3l8agwHWd1/gIX9dpQ1VMX1w8yiHnicnT1T4FkjpSREapbnV8AEMalt82eZe/7ZeqEEnHjKqAyFb6KUZSwMyK3JJ2tTvvJi0AC74XUwZE466oDwql8GkOiMT69uSMLPs3Of/SCRl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787224348; c=relaxed/simple; bh=myVXp0tm8Am90cOphkVFCe075RFIKG12mAWph1JFh14=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=Hfxb3PprmJF6PWO1YVZt4KHJ3Itc6qvJOBN+PtQwjiQ6psj/9+FnOcpHhRh1ab5TEkA4pGM7eSRzJLwSx75wBk+6W/kFlQA9Cyl0w9fJsdUENznyW8gxbeZMSIkWnNk9g2xAuOt4IsT/1LvJadOLVwVtXWHNxTBwDrK5NJNS/b0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=V7UuxATV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="V7UuxATV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFF9F1F000E9; Thu, 20 Aug 2026 11:12:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787224346; bh=LBz2SEXmQBbpRlAG8D50rAZoTDDrQoB6FHJRbEFxXMk=; h=Subject:To:Cc:From:Date; b=V7UuxATVIGfvzzJfyD8ecg1EfGKHLBylUwdbVuwy7lK+3NM7enmNy15KywU8cfrOl wf6xYowuIceFY4k1b4vrBJ8DS1bwl2h6J8VgBmFSvnly4+3b68WNaQ+KVx4TkGDLzy Gm2risXtODry+LSSXDnhVgRWrwZ9TGdYsu78BSyo= Subject: FAILED: patch "[PATCH] libceph: fix OOB read in decode_watchers() via missing bounds" failed to apply to 5.10-stable tree To: jhapavitra98@gmail.com,Slava.Dubeyko@ibm.com,idryomov@gmail.com Cc: From: Date: Thu, 20 Aug 2026 13:11:58 +0200 Message-ID: <2026082058-swiftly-hardwood-656a@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 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 00ead17c7de137a692edee59f2772e6af687e8eb # git commit -s git send-email --to '' --in-reply-to '2026082058-swiftly-hardwood-656a@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 00ead17c7de137a692edee59f2772e6af687e8eb Mon Sep 17 00:00:00 2001 From: Pavitra Jha Date: Wed, 8 Jul 2026 01:39:41 -0400 Subject: [PATCH] libceph: fix OOB read in decode_watchers() via missing bounds check ceph_start_decoding() validates that struct_len bytes remain in the buffer after the encoding header, but accepts struct_len=0 as valid: ceph_decode_need(p, end, 0, bad) always passes. When a malicious or compromised OSD sends an obj_list_watch_response_t reply with struct_len=0, ceph_start_decoding() returns success with p == end, leaving zero bytes guaranteed for subsequent reads. The immediately following ceph_decode_32(p) in decode_watchers() has no preceding bounds check. With p == end this is a 4-byte read past the validated buffer boundary. The garbage value is then passed directly to kzalloc_objs() as the watcher count. The sibling function decode_watcher() already uses the safe variants (ceph_decode_copy_safe, ceph_decode_64_safe, ceph_decode_skip_32) after its own ceph_start_decoding() call. decode_watchers() is the only site that uses the bare variant, confirming an oversight. Fix by replacing ceph_decode_32(p) with ceph_decode_32_safe(p, end, *num_watchers, bad), consistent with the established pattern. Attacker model: a malicious or compromised OSD in a multi-tenant Ceph deployment (e.g. cloud) can trigger this against any kernel client that calls CEPH_OSD_OP_LIST_WATCHERS, without any further privileges beyond OSD session establishment. [ idryomov: trim changelog ] Cc: stable@vger.kernel.org Fixes: a4ed38d7a180 ("libceph: support for CEPH_OSD_OP_LIST_WATCHERS") Signed-off-by: Pavitra Jha Reviewed-by: Viacheslav Dubeyko Signed-off-by: Ilya Dryomov diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 2ff00070c181..28d76c2f6b3e 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -5030,7 +5030,7 @@ static int decode_watchers(void **p, void *end, if (ret) return ret; - *num_watchers = ceph_decode_32(p); + ceph_decode_32_safe(p, end, *num_watchers, bad); *watchers = kzalloc_objs(**watchers, *num_watchers, GFP_NOIO); if (!*watchers) return -ENOMEM; @@ -5044,6 +5044,9 @@ static int decode_watchers(void **p, void *end, } return 0; + +bad: + return -EINVAL; } /*