From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.195 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792994972; b=ycYn5V2tAOr4yUQ+gsFUfUySpB4hh4qGJ1ApeRNS3dpbm9H9gx1VAKLIhVejuPWNExf2 o+1/6rVLG71wwMztGfUDMyfXvfzE/vX8j3PzDT+C3VtU/857Baj2z/4mjY4E0uqU4mEV/ jKL6WMjdLfj3A7SM/GXxNNLRePtCb4Yi0D88QVBI/Fp24SjwBhYHGwajjCBwVyf8QVbiX pvEl4Y7dcxv86kNqgewzngQ2DVJ9vlm7NSDCtjlj1/ayyciZtV5/vuIfkRyG3ZTH8eYnV lr0XooXZqn5V78h08jTDMOYtIxid7PLxETLNPVNmFkott/s4WdN1Wm4xgKMWAU9/4zQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792994972; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:Subject:Date:Message-Id: MIME-Version:Content-Type:Content-Transfer-Encoding:X-B4-Tracking: X-Change-ID:To:Cc:X-Mailer; bh=9/nGkbV+fUPPeLqyGNZSPjPsYCz8iycYQbfenjHMLyo=; b=eipBgGO9c0TJIq2krNtzkmFYGYd56Ihvys3C9smfYumuIBuneHy7nKmiYLRExJjpu/NQ aPVb/ahDjrLb+j5d9kKVOXMr1wOuPSFUues9l+iqun52eR7gW+LEgR2m30S0p3ynPIchu an1VH745xHnuMNtXBbyZCSkO9uAIIWfydnoHOVYhC3DNnjJy62FfvXbKoGG+42Vl6aqHc zGw0wyCw+NVHu5fI/tTLZ8NMd4o9dzRgzQE+8dkWQMxDq2MxfFUVGOHJitemGI6mOeoAe kdUL+9HASS6Koxp4mC9xwLZcWHuFvv8nk1tRD+trmYwo8xXzmznkgZVSwE6NzZ2iUDw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=P7qrESev; arc=none smtp.remote-ip=95.215.58.195 Received: from mta1.migadu.com (out-195.mta1.migadu.com [95.215.58.195]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 517EF606A31A for ; Mon, 26 Oct 2026 06:09:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 517EF606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=P7qrESev X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=2v1X/4ZNw/k4n0QQySBSm3vuF3Ioo/pID4q6JpER+64=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792994969; v=1; x=1793599769; b=P7qrESevDfEBLBVoUte5Tp8c4MLoxJTAP2gUDuLPLCk4+eTBxSt7B/Nk/GtbAhDIjmUp0Prl OHv8KjaMB81GJ5BPGofTkt5we/sMwC7oYnbf/lHbZCId/eGBflwi/OBZRUPhT12KvmSvLRaIzk9 zwpHzemitrIez0ZxjLL0uH0k= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f1f0116670f74061; Mon, 26 Oct 2026 06:09:29 +0000 X-Mizu-Trace-ID: f1f0116670f74061 X-Migadu-Flow: FLOW_OUT From: Ye Liu Subject: [PATCH 0/2] mm/vmalloc: harden remap_vmalloc_range_partial against NULL pages Date: Mon, 26 Oct 2026 14:09:22 +0800 Message-Id: <20261026-vmalloc_remap-v1-0-b7a907814e90@linux.dev> X-Mailing-List: linux-kernel@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="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAJLu3moC/yXMywqAIBCF4VeJWSeoREivEhE2TTXRDS0JonfPa nEW3+L8F3hyTB6K5AJHgT2vS4RKE8DBLj0JbqNBS52rOBFmO00r1o5muwmpNHaZMqitgfjZHHV 8fr2y+u2PZiTc3wjc9wPSLN5scQAAAA== X-Change-ID: 20261026-vmalloc_remap-012cf418c2a8 To: Andrew Morton , Uladzislau Rezki Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ye Liu X-Mailer: b4 0.17-dev-39d60 remap_vmalloc_range_partial() passes vmalloc_to_page()'s result to vm_insert_page() unchecked, oopsing via page_folio() if the page is NULL. The NULL case never happens today because VM_USERMAP areas keep every page mapped, but that assumption is nowhere checked. Patch 1 drops VM_DMA_COHERENT from the allow-list -- a dead entry (no caller maps a DMA-coherent area through this path) whose presence also opens a NULL-deref path, since VM_DMA_COHERENT is not in vrealloc's shrink skip-list. Patch 2 adds a WARN_ON(!page) to flag any future break at the vmalloc_to_page() call site before the oops. Patch 1 is a behavior change (no in-tree caller affected); Patch 2 is dead code. The two are independent. Signed-off-by: Ye Liu --- Ye Liu (2): mm/vmalloc: drop VM_DMA_COHERENT from remap_vmalloc_range_partial mm/vmalloc: warn on NULL page in remap_vmalloc_range_partial mm/vmalloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64 base-tree: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master change-id: 20261026-vmalloc_remap-012cf418c2a8 Best regards, -- Ye Liu