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 3414F2673AA; Sun, 1 Mar 2026 01:54:53 +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=1772330093; cv=none; b=EMFOZfNtVPb+OrPSW8WELKNgIQk0ZNcJNTo8UJy+pFLESuvQ8arLMyinBvEUPEEsQ42tVeIT5DB/8PCHvq6kLHMv2Hb8vkUXPYqWHHoPKlymlWkdP9PaqiTFGiuE5WvmyzW+/34JewzvnLQsDOGED/aRPa3w5IDG8f9BA/OCAHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772330093; c=relaxed/simple; bh=S3kB/6+6+BLwjYDChs0XPyP2t9UMHrtlyqPqoRGzRMs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=VdLnPnu6r7M9nK0TU/ni7s81IIUTB1I32b9s0tX4rrEyzDLdprn0IGH/Vv3VI/dALJeEssbP1PmxY7LHmqtnV6jqipqYSKtlUOhYywcyKkEkUQPT+1GcsQwpIu/uOtWyJELXjJaPz5sRl8UzHBeRqqbNmHljqbQG5b6eKkIOdn4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ghEbZoXa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ghEbZoXa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82417C19424; Sun, 1 Mar 2026 01:54:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772330093; bh=S3kB/6+6+BLwjYDChs0XPyP2t9UMHrtlyqPqoRGzRMs=; h=From:To:Cc:Subject:Date:From; b=ghEbZoXapU4hFEkewBjP9OW2h/TKTNez2RQuX+jkiKuwPIxcs/e/Me+Recp5GI//R Qo5Cb6uJQIXA0iyR3zv7jVGM3I1omX8ouu2Cc0aPcov7XK1A/G1srxBKN4gyERVZXL /3jatjpn5+GVOoVlOYNVFZgKr0h1xNgCKtq/XWhQjLwpHXCrelH+JhQvsGYx1PcP65 mRnLzdU9BtDMAHcr7n+8n9DBivFicY8UdcWHAzF8mFbUdcbh935R0JNBn8GKPXgkLI OTPs/Dh3bHfrPsDoh9ZUTE13w1NwcFoZWbDIIHNIhGEHhlBPlGwFpa82uJ+Sy5YJDd YSMH9ft2zvE/A== From: Sasha Levin To: stable@vger.kernel.org, linkinjeon@kernel.org Cc: tianshuo han , Steve French , linux-cifs@vger.kernel.org Subject: FAILED: Patch "ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths" failed to apply to 5.15-stable tree Date: Sat, 28 Feb 2026 20:54:51 -0500 Message-ID: <20260301015451.1721916-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Hint: ignore X-stable: review 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 . Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 010eb01ce23b34b50531448b0da391c7f05a72af Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 24 Jan 2026 10:55:46 +0900 Subject: [PATCH] ksmbd: fix infinite loop caused by next_smb2_rcv_hdr_off reset in error paths The problem occurs when a signed request fails smb2 signature verification check. In __process_request(), if check_sign_req() returns an error, set_smb2_rsp_status(work, STATUS_ACCESS_DENIED) is called. set_smb2_rsp_status() set work->next_smb2_rcv_hdr_off as zero. By resetting next_smb2_rcv_hdr_off to zero, the pointer to the next command in the chain is lost. Consequently, is_chained_smb2_message() continues to point to the same request header instead of advancing. If the header's NextCommand field is non-zero, the function returns true, causing __handle_ksmbd_work() to repeatedly process the same failed request in an infinite loop. This results in the kernel log being flooded with "bad smb2 signature" messages and high CPU usage. This patch fixes the issue by changing the return value from SERVER_HANDLER_CONTINUE to SERVER_HANDLER_ABORT. This ensures that the processing loop terminates immediately rather than attempting to continue from an invalidated offset. Reported-by: tianshuo han Cc: stable@vger.kernel.org Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/server.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c index 554ae90df906d..d2410a3f163ae 100644 --- a/fs/smb/server/server.c +++ b/fs/smb/server/server.c @@ -126,21 +126,21 @@ static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn, andx_again: if (command >= conn->max_cmds) { conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); - return SERVER_HANDLER_CONTINUE; + return SERVER_HANDLER_ABORT; } cmds = &conn->cmds[command]; if (!cmds->proc) { ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command); conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED); - return SERVER_HANDLER_CONTINUE; + return SERVER_HANDLER_ABORT; } if (work->sess && conn->ops->is_sign_req(work, command)) { ret = conn->ops->check_sign_req(work); if (!ret) { conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED); - return SERVER_HANDLER_CONTINUE; + return SERVER_HANDLER_ABORT; } } -- 2.51.0