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 3EBE0612D7; Tue, 20 Feb 2024 21:41:09 +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=1708465269; cv=none; b=V3GCa8Xkry5sCgS22qa8SO07TxPGX6z1KXrhQxWxpT0O2RFSSJ8C8lKIDyAn2qmyBuQXf20MGy2qY9xSSJ9+prnKVxcNhaU9zwdqr1KV0wxFAhgg1G6p/X9dpxD9Q0qlvWlbu0Q3ehijPelnon6EHT6CHo6oaaCa+84MTDwk8Ms= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708465269; c=relaxed/simple; bh=7FDFFMVf0L6ei5X6UVZxm/r3W+nC2wLvf0NyOBcLbdo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u6ffFXLousZ68Wve2RrOlzZA5VyUV4gviW+Gd2WYxVru07HepmkrlFaPOmPfqshNw7WcEYtsRO8wKFWeJI33NSLAvPw0RnSGws1MPoBapZlADVdDLCfSJg0iIYHabcHQnVcsiFdMCrN4RlZ6G9n8HMDx1A/MXDo/BXdN7LPkhc0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QLfQdEJ9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="QLfQdEJ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1597FC433C7; Tue, 20 Feb 2024 21:41:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708465269; bh=7FDFFMVf0L6ei5X6UVZxm/r3W+nC2wLvf0NyOBcLbdo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QLfQdEJ9uK8MxlTp1Uuw1ZaMi+S3ddvA3TPj6TkFsP9jRiw0HXm7CAIvdEAyRSFDI /FmpyyijeqyWgH+iJkEGfyMNE+zVnlqK4bpE76Z21uPMXca8EODbUfQQYfnogfTXii fqUhrmDwEmgvPaOHc7NInJrrSwC2lJ+QmHy53+O8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "R. Diez" , Ronnie Sahlberg , Matthew Ruffell , Shyam Prasad N , David Howells , Steve French Subject: [PATCH 6.7 260/309] smb: Fix regression in writes when non-standard maximum write size negotiated Date: Tue, 20 Feb 2024 21:56:59 +0100 Message-ID: <20240220205641.284394696@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240220205633.096363225@linuxfoundation.org> References: <20240220205633.096363225@linuxfoundation.org> User-Agent: quilt/0.67 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 6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steve French commit 4860abb91f3d7fbaf8147d54782149bb1fc45892 upstream. The conversion to netfs in the 6.3 kernel caused a regression when maximum write size is set by the server to an unexpected value which is not a multiple of 4096 (similarly if the user overrides the maximum write size by setting mount parm "wsize", but sets it to a value that is not a multiple of 4096). When negotiated write size is not a multiple of 4096 the netfs code can skip the end of the final page when doing large sequential writes, causing data corruption. This section of code is being rewritten/removed due to a large netfs change, but until that point (ie for the 6.3 kernel until now) we can not support non-standard maximum write sizes. Add a warning if a user specifies a wsize on mount that is not a multiple of 4096 (and round down), also add a change where we round down the maximum write size if the server negotiates a value that is not a multiple of 4096 (we also have to check to make sure that we do not round it down to zero). Reported-by: "R. Diez" Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Suggested-by: Ronnie Sahlberg Acked-by: Ronnie Sahlberg Tested-by: Matthew Ruffell Reviewed-by: Shyam Prasad N Cc: stable@vger.kernel.org # v6.3+ Cc: David Howells Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/connect.c | 14 ++++++++++++-- fs/smb/client/fs_context.c | 11 +++++++++++ 2 files changed, 23 insertions(+), 2 deletions(-) --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -3425,8 +3425,18 @@ int cifs_mount_get_tcon(struct cifs_moun * the user on mount */ if ((cifs_sb->ctx->wsize == 0) || - (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) - cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx); + (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx))) { + cifs_sb->ctx->wsize = + round_down(server->ops->negotiate_wsize(tcon, ctx), PAGE_SIZE); + /* + * in the very unlikely event that the server sent a max write size under PAGE_SIZE, + * (which would get rounded down to 0) then reset wsize to absolute minimum eg 4096 + */ + if (cifs_sb->ctx->wsize == 0) { + cifs_sb->ctx->wsize = PAGE_SIZE; + cifs_dbg(VFS, "wsize too small, reset to minimum ie PAGE_SIZE, usually 4096\n"); + } + } if ((cifs_sb->ctx->rsize == 0) || (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx))) cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx); --- a/fs/smb/client/fs_context.c +++ b/fs/smb/client/fs_context.c @@ -1107,6 +1107,17 @@ static int smb3_fs_context_parse_param(s case Opt_wsize: ctx->wsize = result.uint_32; ctx->got_wsize = true; + if (ctx->wsize % PAGE_SIZE != 0) { + ctx->wsize = round_down(ctx->wsize, PAGE_SIZE); + if (ctx->wsize == 0) { + ctx->wsize = PAGE_SIZE; + cifs_dbg(VFS, "wsize too small, reset to minimum %ld\n", PAGE_SIZE); + } else { + cifs_dbg(VFS, + "wsize rounded down to %d to multiple of PAGE_SIZE %ld\n", + ctx->wsize, PAGE_SIZE); + } + } break; case Opt_acregmax: ctx->acregmax = HZ * result.uint_32;