diff options
| author | Dawei Li <set_pte_at@outlook.com> | 2022-11-04 19:05:36 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-12-02 19:40:01 +0300 |
| commit | af9de5cdcb1088b1f9b61814bfa8752f39c13b97 (patch) | |
| tree | 1f0d88842a870dc118f0ae85b557da945ec7b8dc | |
| parent | c40b76dfa7e4b27e861ac7722d1a9f974997d0f0 (diff) | |
| download | linux-af9de5cdcb1088b1f9b61814bfa8752f39c13b97.tar.xz | |
dma-buf: fix racing conflict of dma_heap_add()
[ 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 <set_pte_at@outlook.com>
Acked-by: Andrew Davis <afd@ti.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/TYCP286MB2323873BBDF88020781FB986CA3B9@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/dma-buf/dma-heap.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 798f86fcd50f..dcbb023acc45 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -209,18 +209,6 @@ 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); @@ -259,13 +247,27 @@ 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: |