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 231CA4D0CE5 for ; Wed, 16 Sep 2026 16:53:57 +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=1789577641; cv=none; b=GMjMHMG72SQrgwQHQB3YoXJgBhBqBrE2L5zXRoU9yGri15z2IcPN8CJqAW+sXIQYoNpS3LUpPJdwMw8XsmBzK2jfPKlzuZyri9zVbB10dpK5pKsO0AOuqrzHmYTzE+6obyPnaaMTe/xaKBMRuGwFlGZHezUkMAQD+4DvQu6Ym8c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789577641; c=relaxed/simple; bh=fHcNxdU7akXcag6fWZ8YzjSUmBDAiqmwkXdasjn//Ec=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=pTQVSJIOqIhakCFpIDCad5LPE6GfLw/f4cklhudFYHTD5xa/piTNT10j1NeRl0g7w1eOgeqVmW02ddgudbluG2n/wU1k2du2g7+LEoMKvUoa7nYOl7oU2WQ3A8F0eomLXwr17MnUvjHsAv8DQX9EzjtjaeNJn+oFAVM7I0vvBfQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=s54UwjOi; 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="s54UwjOi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECC631F00899; Wed, 16 Sep 2026 16:53:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789577636; bh=iY2XAS6JPbmciAXlJ5WGrTcDRuxO+jX2wTN0pnT7BvQ=; h=Subject:To:Cc:From:Date; b=s54UwjOi/2wiUtmdrLKmP2gOlRlNLd3fbvT4cxP4FwhQsriBgCqkQiRJrDd4fqmAD ylqA80i9zgghk+Pd0oY4hTowmxAK2oNFgxPmtJeRpOmIfvdpypadH5LodkU969Q4yv pRwhSab3AMSwO1ZZqy61QIcksTQBvtRccIznzXQM= Subject: FAILED: patch "[PATCH] smb: client: avoid using uninitialized SIDs in" failed to apply to 6.18-stable tree To: pc@manguebit.org,bharathsm@microsoft.com,linkinjeon@kernel.org,ronniesahlberg@gmail.com,sprasad@microsoft.com,tom@talpey.com Cc: From: Date: Wed, 16 Sep 2026 17:49:28 +0100 Message-ID: <2026091628-glance-dexterity-17f6@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 6.18-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-6.18.y git checkout FETCH_HEAD git cherry-pick -x da6e25842431982d5a53cf00d925b98c690f4467 # git commit -s git send-email --to '' --in-reply-to '2026091628-glance-dexterity-17f6@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From da6e25842431982d5a53cf00d925b98c690f4467 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sun, 6 Sep 2026 14:40:39 -0300 Subject: [PATCH] smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr() cifs_posix_to_fattr() ignores the return value of posix_info_parse(). When a malformed POSIX directory entry is encountered (e.g. invalid SID lengths from an untrusted server), posix_info_parse() returns -1 without populating the 'parsed' struct. The uninitialized stack memory in parsed.owner and parsed.group is then passed to sid_to_id(), which processes the garbage bytes and passes them to request_key() to construct a SID string, potentially leaking kernel stack contents to the userspace idmap daemon. Fix this by checking the return value and skipping the SID-to-id mapping when parsing fails. The remaining fattr fields (timestamps, mode, etc.) are populated directly from the 'info' pointer so they are unaffected. Closes: https://sashiko.dev/#/patchset/20260906172005.627163-1-pc%40manguebit.org Closes: https://sashiko.dev/#/patchset/20260906181540.647469-1-pc%40manguebit.org Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org diff --git a/fs/smb/client/readdir.c b/fs/smb/client/readdir.c index 1ea84f4ada39..9530e5b01564 100644 --- a/fs/smb/client/readdir.c +++ b/fs/smb/client/readdir.c @@ -244,8 +244,9 @@ cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info, { unsigned int sbflags = cifs_sb_flags(cifs_sb); struct smb2_posix_info_parsed parsed; + int rc; - posix_info_parse(info, NULL, &parsed); + rc = posix_info_parse(info, NULL, &parsed); memset(fattr, 0, sizeof(*fattr)); fattr->cf_uniqueid = le64_to_cpu(info->Inode); @@ -284,10 +285,15 @@ cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info, fattr->cf_uid = cifs_sb->ctx->linux_uid; fattr->cf_gid = cifs_sb->ctx->linux_gid; - if (!(sbflags & CIFS_MOUNT_OVERR_UID)) - sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER); - if (!(sbflags & CIFS_MOUNT_OVERR_GID)) - sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP); + if (rc < 0) { + cifs_dbg(VFS, "%s: failed to parse SIDs: %d\n", + __func__, rc); + } else { + if (!(sbflags & CIFS_MOUNT_OVERR_UID)) + sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER); + if (!(sbflags & CIFS_MOUNT_OVERR_GID)) + sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP); + } } static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)