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habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory

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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: 423815bf02 ("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>
This commit is contained in:
Lv Yunlong 2021-04-26 06:43:46 -07:00 committed by Oded Gabbay
parent 24a107097f
commit 115726c5d3
1 changed files with 3 additions and 1 deletions
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4
drivers/misc/habanalabs/gaudi/gaudi.c
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@ -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;
}