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 335A4346E51; Tue, 16 Dec 2025 11:46:10 +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=1765885571; cv=none; b=E2WXpJT37MOFCwGZjdN2ZGx7iIYFt4JuRQlzUf8LZpuDB9/V010bS5ws0FUkl+CFLdOBKf8d0F8bhLyIe/gRuI78dN2xNeVele4Vo3YqfIhXtzgjv0JwyQbfOG2T8K3cE7zdrFxo9X6sT26Ksl8RaeKzCQ4LOj7RmW9BItZvXM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765885571; c=relaxed/simple; bh=L6ukmDBDI2DkpyMuNFMg/KxOtLkMxtPEwjrTsJOsRj8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mz0IMBgbf7nSQ5hf0Xi7E1RN6cWIJ4x9ut2+zJkkEUfAJED9i+hUETLkPtfw6jUhtdNoM2X8k0MGHuD+/POWODC/tralUA1FkwKuNYTJd75ze2+6NyuoA0Pq7wuaoau3Kv9QSGagH/DNhX8VbwmuHlRvNlYP/05UfrP+HYcOcB4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xua7ruSP; 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="Xua7ruSP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77CB5C4CEF1; Tue, 16 Dec 2025 11:46:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1765885570; bh=L6ukmDBDI2DkpyMuNFMg/KxOtLkMxtPEwjrTsJOsRj8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xua7ruSP4L+71E9zV9vh6FZr+D1gDHIBjlHGp81ktHBIup3nQCr6AvQeMMJWRGJ1Z PqDMQZufHah7B8tnIweCq+I28OUUZoWldepLqrJBeKfVsGqPjcNuTWGjGrEDiSvzQ6 4aQGhRi4D9MAe5gDA2eBNBqXVrP5rLxe4H2n5Yy8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Changzhong , Wang Liang , "Paul E. McKenney" , Frederic Weisbecker , Sasha Levin Subject: [PATCH 6.17 179/507] locktorture: Fix memory leak in param_set_cpumask() Date: Tue, 16 Dec 2025 12:10:20 +0100 Message-ID: <20251216111352.001094335@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251216111345.522190956@linuxfoundation.org> References: <20251216111345.522190956@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 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Liang [ Upstream commit e52b43883d084a9af263c573f2a1bd1ca5088389 ] With CONFIG_CPUMASK_OFFSTACK=y, the 'bind_writers' buffer is allocated via alloc_cpumask_var() in param_set_cpumask(). But it is not freed, when setting the module parameter multiple times by sysfs interface or removing module. Below kmemleak trace is seen for this issue: unreferenced object 0xffff888100aabff8 (size 8): comm "bash", pid 323, jiffies 4295059233 hex dump (first 8 bytes): 07 00 00 00 00 00 00 00 ........ backtrace (crc ac50919): __kmalloc_node_noprof+0x2e5/0x420 alloc_cpumask_var_node+0x1f/0x30 param_set_cpumask+0x26/0xb0 [locktorture] param_attr_store+0x93/0x100 module_attr_store+0x1b/0x30 kernfs_fop_write_iter+0x114/0x1b0 vfs_write+0x300/0x410 ksys_write+0x60/0xd0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f This issue can be reproduced by: insmod locktorture.ko bind_writers=1 rmmod locktorture or: insmod locktorture.ko bind_writers=1 echo 2 > /sys/module/locktorture/parameters/bind_writers Considering that setting the module parameter 'bind_writers' or 'bind_readers' by sysfs interface has no real effect, set the parameter permissions to 0444. To fix the memory leak when removing module, free 'bind_writers' and 'bind_readers' memory in lock_torture_cleanup(). Fixes: 73e341242483 ("locktorture: Add readers_bind and writers_bind module parameters") Suggested-by: Zhang Changzhong Signed-off-by: Wang Liang Signed-off-by: Paul E. McKenney Signed-off-by: Frederic Weisbecker Signed-off-by: Sasha Levin --- kernel/locking/locktorture.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index ce0362f0a8719..6567e5eeacc0e 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -103,8 +103,8 @@ static const struct kernel_param_ops lt_bind_ops = { .get = param_get_cpumask, }; -module_param_cb(bind_readers, <_bind_ops, &bind_readers, 0644); -module_param_cb(bind_writers, <_bind_ops, &bind_writers, 0644); +module_param_cb(bind_readers, <_bind_ops, &bind_readers, 0444); +module_param_cb(bind_writers, <_bind_ops, &bind_writers, 0444); long torture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask, bool dowarn); @@ -1211,6 +1211,10 @@ static void lock_torture_cleanup(void) cxt.cur_ops->exit(); cxt.init_called = false; } + + free_cpumask_var(bind_readers); + free_cpumask_var(bind_writers); + torture_cleanup_end(); } -- 2.51.0