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 3F9AB38AC78 for ; Fri, 24 Apr 2026 09:42:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777023761; cv=none; b=cqZqg8u/1jEJxyDja7pB8Ak07IJ62sGLn6Lc5Vdf+tcYnEIbC5hcBnPpywAfyj4ZU24bd46OT5H1I9gDpIDir3pg11+WRZI1JoQvHRgMIj+Screi7Gsn837+sRCWUKvr+RnFXdbR3jXrG8K2p9qJlVYDGym5lUU6nj09FsC0VO0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777023761; c=relaxed/simple; bh=lV4LzpguxkN1RB58ZIAPpFdrH1JWedzJ+VelhRmm29I=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=ZHrqqPRGsWg8ulUKKPh/iK/QnsQlAJBzenVZP8rQJTNBfYlUdKpb+e3rfbMN0Zc15f9S0WiXsVQ3Tn3SkPZvsRyTxJBF2foIzVY3kMNJ50QlgOwgW4F8mmLarEJEUaQEi8iTNaj9moDbSFtkr+a3sY7EghpfvzS2UffKbLKC/ns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OOk0Zp9b; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OOk0Zp9b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DE07C19425; Fri, 24 Apr 2026 09:42:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777023760; bh=lV4LzpguxkN1RB58ZIAPpFdrH1JWedzJ+VelhRmm29I=; h=Subject:To:Cc:From:Date:From; b=OOk0Zp9bp2mtv1zSzDKICMhFOzXuKOkofsenEAxbL6JwKVIvGrS6tBc/X/as2irvi xZZsR+3bfAU7xp/2Zv8Sc7/+DTsOw7E0034hiXw1WENO3cObaNJc/tVS/AyHj3Ep2b CpuYg5HtPpr4v4fpRi6HmHWR9uUcbV1DZrRL0XWQ= Subject: FAILED: patch "[PATCH] smb: client: require a full NFS mode SID before reading mode" failed to apply to 5.10-stable tree To: michael.bommarito@gmail.com,stfrench@microsoft.com Cc: From: Date: Fri, 24 Apr 2026 11:42:30 +0200 Message-ID: <2026042430-gumball-harmonics-5661@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 2757ad3e4b6f9e0fed4c7739594e702abc5cab21 # git commit -s git send-email --to '' --in-reply-to '2026042430-gumball-harmonics-5661@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 2757ad3e4b6f9e0fed4c7739594e702abc5cab21 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Mon, 20 Apr 2026 09:50:58 -0400 Subject: [PATCH] smb: client: require a full NFS mode SID before reading mode bits parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS mode SID and reads sid.sub_auth[2] to recover the mode bits. That assumes the ACE carries three subauthorities, but compare_sids() only compares min(a, b) subauthorities. A malicious server can return an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still matches sid_unix_NFS_mode and then drives the sub_auth[2] read four bytes past the end of the ACE. Require num_subauth >= 3 before treating the ACE as an NFS mode SID. This keeps the fix local to the special-SID mode path without changing compare_sids() semantics for the rest of cifsacl. Fixes: e2f8fbfb8d09 ("cifs: get mode bits from special sid on stat") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Michael Bommarito Signed-off-by: Steve French diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c index cb4060ba5e31..4ec204d2c774 100644 --- a/fs/smb/client/cifsacl.c +++ b/fs/smb/client/cifsacl.c @@ -879,6 +879,7 @@ static void parse_dacl(struct smb_acl *pdacl, char *end_of_acl, dump_ace(ppace[i], end_of_dacl); #endif if (mode_from_special_sid && + ppace[i]->sid.num_subauth >= 3 && (compare_sids(&(ppace[i]->sid), &sid_unix_NFS_mode) == 0)) { /*