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 4C5B879C0 for ; Wed, 30 Nov 2022 18:48:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2B13C433C1; Wed, 30 Nov 2022 18:48:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669834091; bh=sTXKwoIwrmBKPGu/Yp8Rqee3FuXZ0Ejd9Z9fdqONnbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hCEeLwrRhvH+SneWwozFpmytOfUgdFSr/EeVzQWDnWL/qHykZwAk2MjqFALXb/sEY rO5H5FJyuK0eHIwz8Ko2qOxa3La0nJyTeKjOU7UwDZ3WQfuVwF1uJp/RKdSa2TbgqP cozCkmutgAq2VJN51wmOx2b4bcOQi61kmjmopvF4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dawei Li , Andrew Davis , =?UTF-8?q?Christian=20K=C3=B6nig?= , Sumit Semwal , Sasha Levin Subject: [PATCH 6.0 126/289] dma-buf: fix racing conflict of dma_heap_add() Date: Wed, 30 Nov 2022 19:21:51 +0100 Message-Id: <20221130180546.997188139@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221130180544.105550592@linuxfoundation.org> References: <20221130180544.105550592@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dawei Li [ Upstream commit 432e25902b9651622578c6248e549297d03caf66 ] Racing conflict could be: task A task B list_for_each_entry strcmp(h->name)) list_for_each_entry strcmp(h->name) kzalloc kzalloc ...... ..... device_create device_create list_add list_add The root cause is that task B has no idea about the fact someone else(A) has inserted heap with same name when it calls list_add, so a potential collision occurs. Fixes: c02a81fba74f ("dma-buf: Add dma-buf heaps framework") Signed-off-by: Dawei Li Acked-by: Andrew Davis Acked-by: Christian König Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/TYCP286MB2323873BBDF88020781FB986CA3B9@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM Signed-off-by: Sasha Levin --- drivers/dma-buf/dma-heap.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8f5848aa144f..59d158873f4c 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -233,18 +233,6 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) return ERR_PTR(-EINVAL); } - /* check the name is unique */ - mutex_lock(&heap_list_lock); - list_for_each_entry(h, &heap_list, list) { - if (!strcmp(h->name, exp_info->name)) { - mutex_unlock(&heap_list_lock); - pr_err("dma_heap: Already registered heap named %s\n", - exp_info->name); - return ERR_PTR(-EINVAL); - } - } - mutex_unlock(&heap_list_lock); - heap = kzalloc(sizeof(*heap), GFP_KERNEL); if (!heap) return ERR_PTR(-ENOMEM); @@ -283,13 +271,27 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) err_ret = ERR_CAST(dev_ret); goto err2; } - /* Add heap to the list */ + mutex_lock(&heap_list_lock); + /* check the name is unique */ + list_for_each_entry(h, &heap_list, list) { + if (!strcmp(h->name, exp_info->name)) { + mutex_unlock(&heap_list_lock); + pr_err("dma_heap: Already registered heap named %s\n", + exp_info->name); + err_ret = ERR_PTR(-EINVAL); + goto err3; + } + } + + /* Add heap to the list */ list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock); return heap; +err3: + device_destroy(dma_heap_class, heap->heap_devt); err2: cdev_del(&heap->heap_cdev); err1: -- 2.35.1