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| author | Lv Yunlong <lyl2019@mail.ustc.edu.cn> | 2021-04-26 06:43:46 -0700 |
|---|---|---|
| committer | Oded Gabbay <ogabbay@kernel.org> | 2021-05-08 11:36:07 +0300 |
| commit | 115726c5d312b462c9d9931ea42becdfa838a076 (patch) | |
| tree | a50f50a221cd7b6819051ec50080f2f1a7416951 | |
| parent | 24a107097fbd8fb6a48a0dcb31e64c1de6831a1d (diff) | |
| download | linux-115726c5d312b462c9d9931ea42becdfa838a076.tar.bz2 | |
habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory
Our code analyzer reported a uaf.
In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create()
with 2 refcount.
If hl_cs_allocate_job() failed, the execution runs into release_cb
branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed
if other thread also drops one ref. Then cb is used by cb->id later,
which is a potential uaf.
My patch add a variable 'id' to accept the value of cb->id before the
hl_cb_put(cb) is called, to avoid the potential uaf.
Fixes: 423815bf02e25 ("habanalabs/gaudi: remove PCI access to SM block")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
| -rw-r--r-- | drivers/misc/habanalabs/gaudi/gaudi.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c index 81155f06c126..9e4a6bb3acd1 100644 --- a/drivers/misc/habanalabs/gaudi/gaudi.c +++ b/drivers/misc/habanalabs/gaudi/gaudi.c @@ -5579,6 +5579,7 @@ static int gaudi_memset_device_memory(struct hl_device *hdev, u64 addr, struct hl_cs_job *job; u32 cb_size, ctl, err_cause; struct hl_cb *cb; + u64 id; int rc; cb = hl_cb_kernel_create(hdev, PAGE_SIZE, false); @@ -5645,8 +5646,9 @@ static int gaudi_memset_device_memory(struct hl_device *hdev, u64 addr, } release_cb: + id = cb->id; hl_cb_put(cb); - hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, cb->id << PAGE_SHIFT); + hl_cb_destroy(hdev, &hdev->kernel_cb_mgr, id << PAGE_SHIFT); return rc; } |