[PATCH] RDMA/ocrdma: fix use after free in ocrdma_dealloc_ucontext_pd()

From: trix
Date: Tue Dec 29 2020 - 21:55:29 EST


From: Tom Rix <trix@xxxxxxxxxx>

In ocrdma_dealloc_ucontext_pd() uctx->cntxt_pd is assigned to
the variable pd and then after uctx->cntxt_pd is freed, the
variable pd is passed to function _ocrdma_dealloc_pd() which
dereferences pd directly or through its call to
ocrdma_mbx_dealloc_pd().

Reorder the free using the variable pd.

Fixes: 21a428a019c9 ("RDMA: Handle PD allocations by IB/core")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/infiniband/hw/ocrdma/ocrdma_verbs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
index bc98bd950d99..3acb5c10b155 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_verbs.c
@@ -434,9 +434,9 @@ static void ocrdma_dealloc_ucontext_pd(struct ocrdma_ucontext *uctx)
pr_err("%s(%d) Freeing in use pdid=0x%x.\n",
__func__, dev->id, pd->id);
}
- kfree(uctx->cntxt_pd);
uctx->cntxt_pd = NULL;
_ocrdma_dealloc_pd(dev, pd);
+ kfree(pd);
}

static struct ocrdma_pd *ocrdma_get_ucontext_pd(struct ocrdma_ucontext *uctx)
--
2.27.0