Messages in this thread | | | Subject | Re: [rds-devel] KASAN: null-ptr-deref Read in rds_ib_get_mr | From | Yanjun Zhu <> | Date | Fri, 11 May 2018 22:07:45 +0800 |
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On 2018/5/11 18:46, Sowmini Varadhan wrote: > On (05/11/18 15:48), Yanjun Zhu wrote: >> diff --git a/net/rds/ib_rdma.c b/net/rds/ib_rdma.c >> index e678699..2228b50 100644 >> --- a/net/rds/ib_rdma.c >> +++ b/net/rds/ib_rdma.c >> @@ -539,11 +539,17 @@ void rds_ib_flush_mrs(void) >> void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents, >> struct rds_sock *rs, u32 *key_ret) >> { >> - struct rds_ib_device *rds_ibdev; >> + struct rds_ib_device *rds_ibdev = NULL; >> struct rds_ib_mr *ibmr = NULL; >> - struct rds_ib_connection *ic = rs->rs_conn->c_transport_data; >> + struct rds_ib_connection *ic = NULL; >> int ret; >> >> + if (rs->rs_bound_addr == 0) { >> + ret = -EPERM; >> + goto out; >> + } >> + >> + ic = rs->rs_conn->c_transport_data; >> rds_ibdev = rds_ib_get_device(rs->rs_bound_addr); >> if (!rds_ibdev) { >> ret = -ENODEV; >> >> I made this raw patch. If you can reproduce this bug, please make tests >> with it. > I dont think this solves the problem, I think it > just changes the timing under which it can still happen. > > what if the rds_remove_bound() in rds_bind() happens after the check > for if (rs->rs_bound_addr == 0) added above by the patch > > I believe you need some type of synchronization (either > through mutex, or some atomic flag in the rs or similar) to make > sure rds_bind() and rds_ib_get_mr() are mutually exclusive. Sure. I agree with you. Maybe mutex is a good choice.
Zhu Yanjun > > --Sowmini > > >
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