From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793817050; b=fQ0j3lAPkyFub0KxSjhWdpZL2QBTMWxKWpzQaaWe702XB2ko8OcoJZ0xu2ZpQpqqTNuw BLYZnKagwWA4ziSKYniwtOWlMmQ21E1Cp3VmU7VLHEqCrZRAkTaRp2gzft6uOWmzDIQSz n6DftvpuX9+iGxGNGnEyUsaXVCmHDkR73MqvO7YPEP/mqLWQreO1ojcxzn9IdlS/bdNmk WP8RqGWocIP9nEXo5RNZ3/FSjMaObj/o6/w4xqrzvuH5SIHQc+iC9xuENM1IhSZsURSAd RlgcBngjDUJZ4EUWnN9Mdw93MAVm0YyrQkhayksxgbRn3mQKupxcR3c/e7v3AwcoFaQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793817050; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=xpZgNaK2CLYSpm/IFDq1bnJxhNJCwpwKoFK+podNpXg=; b=t1pNV+LzDcvv3unFeCyzNUVG3gydJHCgm/0pkwOeQbv8oLjc+OMCoN/aK5e3acv+EeN7 A6PVHxRziv+7wNq722dWGX5+ptiBrlY7oOt5Es4WODv9Wc/ZZUMPxBZXPy6MX8KnVT8y/ 8y8QwIp/RJ9m05WRPGLedYioUTCPxBXeSUj3MEn6eIeQ6HCcjTKCty9aQq87DiXj0LKJF 6n+M/9dzX0MFy6qkbQN0vmG4wk/1VyUk0BFnqmrkxT1yHG+I8GoWxfAUPd8DgF4X0fgVB WMzxvixXdlDBOZVrnCHkmL7ThWZHsynI4zJX3Nxq5BEHxn6qk7I3yKxPkCLjoXkn5Xw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=w+ycXY1v; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4DF0606A326 for ; Wed, 4 Nov 2026 18:30:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=w+ycXY1v Received: by smtp.kernel.org (Postfix) with ESMTPSA id 536801F000C1; Wed, 4 Nov 2026 18:30:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793817049; bh=xpZgNaK2CLYSpm/IFDq1bnJxhNJCwpwKoFK+podNpXg=; h=Subject:To:Cc:From:Date; b=w+ycXY1vFctEkfCNVQqOJZq67yGF6zfJLMp9NAvouxWqvck2AmEWmAWZaMburhasC jji4cq5I8mAjFfjvdTyqZLrLcldHbTMJRKpVzgNGn6Q9SAt1ozJAiGkJvLADS0emcd 1naeZu279FVpv0/+uD90YN9SHtdW5VrbJNe3Boxc= Subject: FAILED: patch "[PATCH] smb: client: fix fiemap wild read on empty truncated response" failed to apply to 5.15-stable tree To: suruurism@gmail.com,pc@manguebit.org Cc: From: Date: Wed, 04 Nov 2026 13:30:48 -0500 Message-ID: <2026110448-clunky-cupped-464c@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc # git commit -s git send-email --to '' --in-reply-to '2026110448-clunky-cupped-464c@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f5baa17a0f316c235d61623ac8e8fb32c2b3c0cc Mon Sep 17 00:00:00 2001 From: Abdifatah Suruur Date: Fri, 23 Oct 2026 14:52:46 +0300 Subject: [PATCH] smb: client: fix fiemap wild read on empty truncated response smb3_fiemap() treats -E2BIG from SMB2_ioctl() as a truncated range blob and loops for the next chunk. If the server reports STATUS_BUFFER_OVERFLOW with OutputCount == 0, SMB2_ioctl() returns -E2BIG with out_data == NULL and out_data_len == 0, and the existing length checks accept the empty result. The loop then evaluates next = out_data[num - 1].file_offset + ... with num == 0, reading 16 bytes before NULL. Reject a truncated range blob that contains no range, so the resume offset is never computed from an empty response. Also require the last range in a truncated blob to advance the resume offset without overflowing, and to stay within the requested range; a malicious or broken server could otherwise make no progress or underflow len and loop forever. Free the previous response buffer before retrying. Reproduced on 6.6.87.2 with a malicious SMB2 server that answers FSCTL_QUERY_ALLOCATED_RANGES with STATUS_BUFFER_OVERFLOW and OutputCount == 0; an FS_IOC_FIEMAP ioctl on the mount oopses in cifs_fiemap() with CR2 = fffffffffffffff8. The code path is unchanged on mainline. Fixes: 2f3ebaba13ce ("cifs: add fiemap support") Cc: stable@vger.kernel.org Signed-off-by: Abdifatah Suruur Signed-off-by: Paulo Alcantara diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 20624f5dff9b..dc55cd512616 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -4360,6 +4360,15 @@ static int smb3_fiemap(struct cifs_tcon *tcon, goto out; } + /* + * A truncated range blob must contain at least one range, otherwise + * there is no offset to resume from and out_data is NULL. + */ + if (!last_blob && out_data_len == 0) { + rc = -EINVAL; + goto out; + } + num = out_data_len / sizeof(struct file_allocated_range_buffer); for (i = 0; i < num; i++) { flags = 0; @@ -4380,10 +4389,25 @@ static int smb3_fiemap(struct cifs_tcon *tcon, } if (!last_blob) { - next = le64_to_cpu(out_data[num - 1].file_offset) + - le64_to_cpu(out_data[num - 1].length); - len = len - (next - start); + u64 last_start, last_len; + + last_start = le64_to_cpu(out_data[num - 1].file_offset); + last_len = le64_to_cpu(out_data[num - 1].length); + + if (check_add_overflow(last_start, last_len, &next) || + next <= start) { + rc = -EINVAL; + goto out; + } + if (next - start >= len) { + rc = 0; + goto out; + } + + len -= next - start; start = next; + kfree(out_data); + out_data = NULL; goto again; }