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 2EAFF36A36C; Tue, 16 Jun 2026 18:20:53 +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=1781634054; cv=none; b=Idj2IYIBX6NQu37y1iEh3lVPMnUOqJfvBkeoYhknTWQr6fzJUwNFO5kK/rxH2z76S/QRFPI6kmhUYmcIZddqUoi6v+rPiKhTA/Kfs3Ux0RkD0SzUyoKNJ1owFtKbfRqUURFPM8hu+7ntt+mwVe3OBTi3kFUk+FNM7NNuE5kYcOk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781634054; c=relaxed/simple; bh=pdDuz5x3/Zi/P6Gh678DmFEa51RwhxApvPyfxqBjjjc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=amAr3UPla7ADT0CsTsxVOCsbkOXP4drWk5cXSr6sCXGY9lsG1xn3CuOWAWIWIyyZZneXfX5bnWEe3dYW47HgF8dfmqNkiSYFpa+XAGu/SMW6WG11+qSMAfr80Wqlc+kw4izESbywUI46/sm1sPn8h7UacA3uz2u/Lx9xoOJEVMo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CHkDs8xB; 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="CHkDs8xB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13B251F00A3A; Tue, 16 Jun 2026 18:20:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781634053; bh=7aJZtCloKiiTD6jk+rNzKfD1Ajamr9swigPeNZWr2pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CHkDs8xBT7G1wN3un51UEigkEAlrZmaNgc6dwCIX88CA3eZh/Q+2skKUb0YD+aMUr bO9ojZyqVlOM3OsKgY/pq+IdcjYDYukC6fFKQiqbdtTJ0WQ9fJBVO3N4x46IO9Nr8K MBwunNXSOajtBkay3vEQpvQaHYCiR+uV9SkbEwDE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Breno Leitao , Allison Henderson , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 191/411] rds: mark snapshot pages dirty in rds_info_getsockopt() Date: Tue, 16 Jun 2026 20:27:09 +0530 Message-ID: <20260616145110.861896051@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao [ Upstream commit 512db8267b73a220a64180d95ab5eebe7c4964a8 ] rds_info_getsockopt() pins the destination user pages with FOLL_WRITE and the RDS_INFO_* producers memcpy the snapshot into them through kmap_atomic(). Because that copy goes through the kernel direct map, the dirty bit on the user PTE is never set, so unpin_user_pages() releases the pages without marking them dirty. A file-backed destination page can then be reclaimed without writeback, silently discarding the copied data. Use unpin_user_pages_dirty_lock() with make_dirty=true so the modified pages are marked dirty before they are unpinned. Fixes: a8c879a7ee98 ("RDS: Info and stats") Signed-off-by: Breno Leitao Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260608-rds_fix-v1-1-006c88543408@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/rds/info.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/info.c b/net/rds/info.c index b6b46a8214a0a5..b3ee5f8238c44d 100644 --- a/net/rds/info.c +++ b/net/rds/info.c @@ -235,7 +235,7 @@ int rds_info_getsockopt(struct socket *sock, int optname, char __user *optval, out: if (pages) - unpin_user_pages(pages, nr_pages); + unpin_user_pages_dirty_lock(pages, nr_pages, true); kfree(pages); return ret; -- 2.53.0