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 C49323242BA; Sat, 30 May 2026 16:49:05 +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=1780159747; cv=none; b=az2sA4OZCbf1z70z3YAgfurztDGvhHnRdcGXgNA/Qgd8LA4O2B/7hbHYuLqVyTCIM+mjtAegIDLTEIxCH0QRe5rGMUTQeJWLvPiBNkL21DuZlQi1EByM2qUxZw1yxlDK4g4uN93sXEh18kthlH0srVl3YmwVBK1Clj0XN1hKGVo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780159747; c=relaxed/simple; bh=NpEmDmCMvvZPRTMQN/+qcCzG94y+5UqMgBiW+PxBV9c=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jiq2tOXCLxc1APURAMT82Sn6d6mISBqgBha1KUn0+WTnzhqsayBiw7HdF2jyiax4Z6VLdmaPLOqb6GkN28KzAGPUKVSjaXA1orB7hm3jYpyNMDEhAwagX5DhHsVfZz9uny2nvZfpmm0H+hkIW9ZaqH8NlrsdbSFif5J+5AClmYU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Sjrkn/Q9; 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="Sjrkn/Q9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B275E1F00893; Sat, 30 May 2026 16:49:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780159745; bh=h6n2loZ4hACeNYPQAJlAw18Zf8K2LFE5wBdepAL9Nls=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Sjrkn/Q9L30rqILVsh/CiiLlbCsyetWwZLAJnYvvBEga54L5Z3qkZ+tHt3bpFxgol /2NlP7xNRwtdJOQ7AqotslndEGval5elK4V2oP06C/VhM6bnCAziiYsYOxtiYdRVy0 JXnlUw1/RqK379piF95d2nx3bx9TXDeDWMs0vW4k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tristan Madani , Namjae Jeon , Steve French Subject: [PATCH 6.1 150/969] ksmbd: fix out-of-bounds write in smb2_get_ea() EA alignment Date: Sat, 30 May 2026 17:54:34 +0200 Message-ID: <20260530160304.693380345@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tristan Madani commit 30010c952077a1c89ecdd71fc4d574c75a8f5617 upstream. smb2_get_ea() applies 4-byte alignment padding via memset() after writing each EA entry. The bounds check on buf_free_len is performed before the value memcpy, but the alignment memset fires unconditionally afterward with no check on remaining space. When the EA value exactly fills the remaining buffer (buf_free_len == 0 after value subtraction), the alignment memset writes 1-3 NUL bytes past the buf_free_len boundary. In compound requests where the response buffer is shared across commands, the first command (e.g., READ) can consume most of the buffer, leaving a tight remainder for the QUERY_INFO EA response. The alignment memset then overwrites past the physical kvmalloc allocation into adjacent kernel heap memory. Add a bounds check before the alignment memset to ensure buf_free_len can accommodate the padding bytes. This is the same bug pattern fixed by commit beef2634f81f ("ksmbd: fix potencial OOB in get_file_all_info() for compound requests") and commit fda9522ed6af ("ksmbd: fix OOB write in QUERY_INFO for compound requests"), both of which added bounds checks before unconditional writes in QUERY_INFO response handlers. Cc: stable@vger.kernel.org Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound") Signed-off-by: Tristan Madani Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/smb2pdu.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -4495,6 +4495,8 @@ static int smb2_get_ea(struct ksmbd_work /* align next xattr entry at 4 byte bundary */ alignment_bytes = ((next_offset + 3) & ~3) - next_offset; if (alignment_bytes) { + if (buf_free_len < alignment_bytes) + break; memset(ptr, '\0', alignment_bytes); ptr += alignment_bytes; next_offset += alignment_bytes;