diff options
| author | Ka-Cheong Poon <ka-cheong.poon@oracle.com> | 2020-04-08 12:21:02 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-04-09 19:22:00 +0200 |
| commit | 2fabef4f65b46b261434a27ecdce291b63de8522 (patch) | |
| tree | 5c318bbf58af67e56b085332648cac599973b3fb /net/rds/rds.h | |
| parent | net/rds: Replace struct rds_mr's r_refcount with struct kref (diff) | |
| download | linux-2fabef4f65b46b261434a27ecdce291b63de8522.tar.xz linux-2fabef4f65b46b261434a27ecdce291b63de8522.zip | |
net/rds: Fix MR reference counting problem
In rds_free_mr(), it calls rds_destroy_mr(mr) directly. But this
defeats the purpose of reference counting and makes MR free handling
impossible. It means that holding a reference does not guarantee that
it is safe to access some fields. For example, In
rds_cmsg_rdma_dest(), it increases the ref count, unlocks and then
calls mr->r_trans->sync_mr(). But if rds_free_mr() (and
rds_destroy_mr()) is called in between (there is no lock preventing
this to happen), r_trans_private is set to NULL, causing a panic.
Similar issue is in rds_rdma_unuse().
Reported-by: zerons <sironhide0null@gmail.com>
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/rds/rds.h')
| -rw-r--r-- | net/rds/rds.h | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/net/rds/rds.h b/net/rds/rds.h index 3cda01cfaa56..8e18cd2aec51 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -299,19 +299,11 @@ struct rds_mr { unsigned int r_invalidate:1; unsigned int r_write:1; - /* This is for RDS_MR_DEAD. - * It would be nice & consistent to make this part of the above - * bit field here, but we need to use test_and_set_bit. - */ - unsigned long r_state; struct rds_sock *r_sock; /* back pointer to the socket that owns us */ struct rds_transport *r_trans; void *r_trans_private; }; -/* Flags for mr->r_state */ -#define RDS_MR_DEAD 0 - static inline rds_rdma_cookie_t rds_rdma_make_cookie(u32 r_key, u32 offset) { return r_key | (((u64) offset) << 32); |