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 9E55C3F8883 for ; Thu, 20 Aug 2026 11:12:22 +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=1787224343; cv=none; b=SLlIO+iXOLIyvt8Rh5cL1fGcUacofws/2TmMC8nXCwqvwht2oBhEMxYpxk2xIX3XhcQKit+hWr4z4bGmBE5xufJTM1k9ieuDefFk9y+uRXRY9c9Hq8pi4Es/VnvC3T0A8n75IXnuGd9airpRq6eH42wPCCW3TLH1/X2ZZBHe+5g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787224343; c=relaxed/simple; bh=eMb3Z6pSVa2dykHZffFBvIUHZetoWIXHEu2tGmDgXbo=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=S4m8sBx+gRC0bcmjJs7Z6DEcyN8LTakGj3AXVImBNwsH4IZYKICSp+cRzBmHgevHiJWCCV23fZxt/SZnWDNnv/fLHx9lM0VR28txB9u3XYLEDPsiKoKcG8HYZTLrNxDrwi9iePbyRxeU+EZx0a6hk1hEvZnH+j2Ue+q0y4Ag87I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dTJiLLdq; 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="dTJiLLdq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8E221F000E9; Thu, 20 Aug 2026 11:12:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787224342; bh=tbavwgQsmNb3ewwh1en6mrOOLZtNMy9mzSTIk3XnXL8=; h=Subject:To:Cc:From:Date; b=dTJiLLdqZObGXlJuQfe1K2IDAS5NIU1AKnlH3sYD9x5qdFUwogGRtcj36al/bp/T2 cfDvcQhelHE+gf5xHHt85kQzIVQs1l22fEzFgxdOr5hrK5a3PFTv8rA7Qi4+gVhyqi iIc6T4i1/20R+cBhYtDU35vLlT7HYvLRea39vm1s= Subject: FAILED: patch "[PATCH] libceph: fix OOB read in decode_watchers() via missing bounds" failed to apply to 6.1-stable tree To: jhapavitra98@gmail.com,Slava.Dubeyko@ibm.com,idryomov@gmail.com Cc: From: Date: Thu, 20 Aug 2026 13:11:57 +0200 Message-ID: <2026082057-overload-cycle-4a9a@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 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x 00ead17c7de137a692edee59f2772e6af687e8eb # git commit -s git send-email --to '' --in-reply-to '2026082057-overload-cycle-4a9a@gregkh' --subject-prefix 'PATCH 6.1.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; } /*