From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-48.mta0.migadu.com [91.218.175.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 58DEE51E439 for ; Tue, 8 Sep 2026 09:25:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788859529; cv=none; b=Vj43mffSe2VbYRXrsNB7QMwWOfQcnkBXSoOutFKv6R124+w2madfN/dAFKmgU4JMdbOgj6sbDyaYiZLtoqQ0Rt3TkiSdzprFgW3sdrvVyAIn5UwCsiBI6iCDwwCMAaRHH2/l1xV0zc/hoj+AxPRC0ohHP1m4X2oFFZ9STlHMfg0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788859529; c=relaxed/simple; bh=LBg+sSLJXtOw4WEz6FbemiKRacEtP0xCjkkrVUCvXnY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=rC50ZD92L+9turg28z4+tT/HMIxXMUWkADiBJnxPcvmMhWFu4Ma1emq6SZ08cKwQaX+UsKqAHjKEejt0LRsoVNTVyVREk/6GeKCEqFs+Bshj+4ZTLoV3os9CBJEFaIovGNL7eD64RZs6tFZ4NzveVIvroWCf97Ut+U11ntMRorA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=xkjjv8Qk; arc=none smtp.client-ip=91.218.175.48 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) header.d=linux.dev header.i=@linux.dev header.b="xkjjv8Qk" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=LBg+sSLJXtOw4WEz6FbemiKRacEtP0xCjkkrVUCvXnY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788859526; v=1; x=1789464326; b=xkjjv8QkGbLFxmumUWQo4JmgAxkQdSsD3poo1JVJvohVH54wQYpRVSmscrnbe3XBjOUUoZQE hQBRbWe66aujOa/v3EIf+Vw0P2EtRZ3WwlJywiexqmvjcmHx1KlvS9HJo9eDnk0iJTMsLMAkCAw gkWmDBKkN2Vydw4zjcWzGHNU= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 7cf99981dc3c1c49; Tue, 08 Sep 2026 09:25:07 +0000 X-Mizu-Trace-ID: 7cf99981dc3c1c49 X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Luis Chamberlain , Petr Pavlu , Daniel Gomez , Sami Tolvanen , Aaron Tomlin , Suren Baghdasaryan , Hao Ge , Andrew Morton Cc: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Sashiko , stable@vger.kernel.org Subject: [PATCH v9 2/4] alloc_tag: clean up the populate failure path Date: Tue, 8 Sep 2026 17:24:10 +0800 Message-Id: <20260908092412.115953-3-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260908092412.115953-1-hao.ge@linux.dev> References: <20260908092412.115953-1-hao.ge@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The reservation is already stored in the maple tree when vm_module_tags_populate() fails. A failed load never unloads the module, so nothing releases the entry. Release it and roll module_tags.size back. Without the rollback a concurrent load that already passed needs_section_mem() can reuse the freed gap, skip vm_module_tags_populate() and write to unmapped memory. vmap_pages_range() may have installed some PTEs before failing. A retry to populate the same range would BUG on them, so undo them, but only if vmap actually ran. Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression") Fixes: 0f9b685626da ("alloc_tag: populate memory for module tags as needed") Reported-by: Sashiko Cc: stable@vger.kernel.org Signed-off-by: Hao Ge --- mm/alloc_tag.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index e7a79116ad81..e7a40a276ed9 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -812,6 +812,13 @@ static int vm_module_tags_populate(void) next_page, PAGE_SHIFT) < 0) { release_pages_arg arg = { .pages = next_page }; + /* + * vmap_pages_range() only runs once all pages were + * allocated, and it may have installed some mappings + * before failing. Undo them. + */ + if (nr == more_pages) + vunmap_range(phys_end, phys_end + (nr << PAGE_SHIFT)); /* Clean up and error out */ release_pages(arg, nr); return -ENOMEM; @@ -955,6 +962,7 @@ static void *reserve_module_tags(struct module *mod, unsigned long size, return ret; if (module_tags.size < offset + size) { + unsigned long prev_size = module_tags.size; int grow_res; module_tags.size = offset + size; @@ -969,6 +977,8 @@ static void *reserve_module_tags(struct module *mod, unsigned long size, shutdown_mem_profiling(true); pr_err("Failed to allocate memory for allocation tags in the module %s. Memory allocation profiling is disabled!\n", mod->name); + release_module_tags(mod, false); + module_tags.size = prev_size; return ERR_PTR(grow_res); } } -- 2.25.1