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 8C59213D601; Thu, 13 Jun 2024 12:10:32 +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=1718280632; cv=none; b=oBMnA9ayl2gzov2E2WLSgvw/QY8k7zvTqWoHHhlSaCJmBTLLhAXupus+SNzLyzfikRxm8f1RYJXX34vTnxeRXCPl9HMiWoP0wt9omW5ODUjeL3vwJMaDpJkoHGrOhqN9lKKTptiABCIUwkAnEe10OT6tYfuPwnqBiSUNUYeIlmY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718280632; c=relaxed/simple; bh=YYa6FzmPY/ua8sUgtDwKrMYoEraBh3a+PrqtNgVwbX8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Fpx9vcSb+mMnSOUo+OzbHuNic4PtwXMKWITuBkmhnd/at4LqZk2re9wjlFANxgflQMLQz4ojKB482s/k6idRJkMajOIiEbaywd/fI3gYKn/5Gnp9SA4oFKsH+12+oAV2z2oFWIIxMIaMQwLzyehC7QR0aTWEOGGt8J6e95WH2PQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xXtAdKqJ; 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="xXtAdKqJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14337C2BBFC; Thu, 13 Jun 2024 12:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1718280632; bh=YYa6FzmPY/ua8sUgtDwKrMYoEraBh3a+PrqtNgVwbX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xXtAdKqJ51GKvCJLymqpXvkSZyT3hqmagUh7FJ0VcZzV0tTCWOMUV21JtGdLIu30z vgjc8gJ3GFStuZBQKjCjVmAcCEsM25UOiFse57p8UyTV8VgnqnkJkk9gE0JkooFVuA nKRDDBIwwdTSM+E0N+vYPoTAjjLWnzGDl4zVH6vk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "dicken.ding" , Thomas Gleixner Subject: [PATCH 6.6 120/137] genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() Date: Thu, 13 Jun 2024 13:35:00 +0200 Message-ID: <20240613113227.955167134@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240613113223.281378087@linuxfoundation.org> References: <20240613113223.281378087@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: dicken.ding commit b84a8aba806261d2f759ccedf4a2a6a80a5e55ba upstream. irq_find_at_or_after() dereferences the interrupt descriptor which is returned by mt_find() while neither holding sparse_irq_lock nor RCU read lock, which means the descriptor can be freed between mt_find() and the dereference: CPU0 CPU1 desc = mt_find() delayed_free_desc(desc) irq_desc_get_irq(desc) The use-after-free is reported by KASAN: Call trace: irq_get_next_irq+0x58/0x84 show_stat+0x638/0x824 seq_read_iter+0x158/0x4ec proc_reg_read_iter+0x94/0x12c vfs_read+0x1e0/0x2c8 Freed by task 4471: slab_free_freelist_hook+0x174/0x1e0 __kmem_cache_free+0xa4/0x1dc kfree+0x64/0x128 irq_kobj_release+0x28/0x3c kobject_put+0xcc/0x1e0 delayed_free_desc+0x14/0x2c rcu_do_batch+0x214/0x720 Guard the access with a RCU read lock section. Fixes: 721255b9826b ("genirq: Use a maple tree for interrupt descriptor management") Signed-off-by: dicken.ding Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240524091739.31611-1-dicken.ding@mediatek.com Signed-off-by: Greg Kroah-Hartman --- kernel/irq/irqdesc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -148,7 +148,10 @@ static int irq_find_free_area(unsigned i static unsigned int irq_find_at_or_after(unsigned int offset) { unsigned long index = offset; - struct irq_desc *desc = mt_find(&sparse_irqs, &index, nr_irqs); + struct irq_desc *desc; + + guard(rcu)(); + desc = mt_find(&sparse_irqs, &index, nr_irqs); return desc ? irq_desc_get_irq(desc) : nr_irqs; }