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 732EF39934B; Sat, 17 Oct 2026 16:50:59 +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=1792255860; cv=none; b=FsXvbNoDUYa48iS8we2dAfMwVGFZdcti+TI5pfAl3XUr258Y1bxgUQHAnrhIsSfB+d2VBpKLx9FMc1mp4yywf9S5e1E2hp5SX9i3aVR08h3/Olc1zd6LlhgAL1o0EMnBOZlj0K3LBMHuz2gIWfZ9o0W9WGrv1vfCpGFLXtr8Ej0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792255860; c=relaxed/simple; bh=HeSONrxiHCdklCGNrQ8qhEUdDS/4l3eGoHb2If9tsww=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OL17WNWzujCL9pNdD6azcsjDeJX1TIlsrNK+kc0jHZynTo8h6cU0WAHC2hTj7Msu/dWXPLG6lH86wQKOis/o2PV2bE1YoN2Rf7PrbhXbIAdoo07bz5s90ewpOrwWsL5q76OCmQcDcOKxTwz6GY0Q5w20fxwTojAhHaOdj8JM7w4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gxyzEcNl; 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="gxyzEcNl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C087B1F000C4; Sat, 17 Oct 2026 16:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792255859; bh=BaLSS7WFTqpQrmzw2AAmol7CXnIEJh7EqMGyhDbJ+JM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gxyzEcNlZa/owyUYPDW+MQaePbRdX1AeM5WEPBgLHT+jJ2xlJxBq46ieNv1ajBnwD FyjCwkpaMrHgMmSlrcbbMvK6QIpD5uYzzWDsj6GWboESEfDoZvoBBRJEiAFq6eymdO Aa4UkIOZyzYad38p7eg5+uUFBCnkLRP6mKwUDQ4E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Sorenson , David Howells , Paulo Alcantara , Sasha Levin Subject: [PATCH 6.6 0045/1674] smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs() Date: Sat, 17 Oct 2026 17:38:37 +0200 Message-ID: <20261017160432.294623930@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261017160431.119607952@linuxfoundation.org> References: <20261017160431.119607952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson [ Upstream commit eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb ] In move_smb2_ea_to_cifs(), the while (src_size > 0) loop condition is insufficient. It allows iteration to continue even if the remaining src_size is too small to contain a complete smb2_ea_info structure. Consequently, reads of ea_name_length and ea_value_length can occur out-of-bounds. Fix this by ensuring src_size >= sizeof(*src) before attempting to read any structure fields. Additionally, reject any next_entry_offset that is smaller than sizeof(*src) or that would advance the pointer beyond the available buffer. Note that for calls where the server returns a malformed EA list, the error returned to userspace changes from -ENODATA (getxattr) or -ERANGE (listxattr) to -EIO. This correctly signals a server protocol error rather than misleadingly indicating "attribute not present" or "output buffer too small". Fixes: 95907fea4fd8 ("cifs: Add support for reading attributes on SMB2+") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson Reviewed-by: David Howells Signed-off-by: Paulo Alcantara [ Replaced unavailable smb_EIO2() tracing calls with -EIO. ] Signed-off-by: Sasha Levin --- fs/smb/client/smb2ops.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index bc1fdeee98466..887ffa77aa183 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -1014,8 +1014,9 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, char *name, *value; size_t buf_size = dst_size; size_t name_len, value_len, user_name_len; + u32 next_off; - while (src_size > 0) { + while (src_size >= sizeof(*src)) { name_len = (size_t)src->ea_name_length; value_len = (size_t)le16_to_cpu(src->ea_value_length); @@ -1070,14 +1071,21 @@ move_smb2_ea_to_cifs(char *dst, size_t dst_size, if (!src->next_entry_offset) break; - if (src_size < le32_to_cpu(src->next_entry_offset)) { - /* stop before overrun buffer */ - rc = -ERANGE; - break; + next_off = le32_to_cpu(src->next_entry_offset); + if (next_off < sizeof(*src) || src_size < next_off) { + cifs_dbg(FYI, "EA next_entry_offset %u out of range [%zu, %zu]\n", + next_off, sizeof(*src), src_size); + rc = -EIO; + goto out; + } + src_size -= next_off; + src = (void *)((char *)src + next_off); + if (src_size > 0 && src_size < sizeof(*src)) { + cifs_dbg(FYI, "EA next_entry_offset %u left truncated entry (%zu bytes)\n", + next_off, src_size); + rc = -EIO; + goto out; } - src_size -= le32_to_cpu(src->next_entry_offset); - src = (void *)((char *)src + - le32_to_cpu(src->next_entry_offset)); } /* didn't find the named attribute */ -- 2.53.0