From: Mikhail Malygin m.malygin@yadro.com
[ Upstream commit 5f0b2a6093a4d9aab093964c65083fe801ef1e58 ]
rxe_post_send_kernel() iterates over linked list of wr's, until the wr->next ptr is NULL. However if we've got an interrupt after last wr is posted, control may be returned to the code after send completion callback is executed and wr memory is freed.
As a result, wr->next pointer may contain incorrect value leading to panic. Store the wr->next on the stack before posting it.
Fixes: 8700e3e7c485 ("Soft RoCE driver") Link: https://lore.kernel.org/r/20200716190340.23453-1-m.malygin@yadro.com Signed-off-by: Mikhail Malygin m.malygin@yadro.com Signed-off-by: Sergey Kojushev s.kojushev@yadro.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/sw/rxe/rxe_verbs.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 9dd4bd7aea92e..2aaa0b592a2d8 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -683,6 +683,7 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, unsigned int mask; unsigned int length = 0; int i; + struct ib_send_wr *next;
while (wr) { mask = wr_opcode_mask(wr->opcode, qp); @@ -699,6 +700,8 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, break; }
+ next = wr->next; + length = 0; for (i = 0; i < wr->num_sge; i++) length += wr->sg_list[i].length; @@ -709,7 +712,7 @@ static int rxe_post_send_kernel(struct rxe_qp *qp, const struct ib_send_wr *wr, *bad_wr = wr; break; } - wr = wr->next; + wr = next; }
rxe_run_task(&qp->req.task, 1);