[ Upstream commit 1748f6a2cbc4694523f16da1c892b59861045b9d ]
The rcu_dereference call in rht_ptr_rcu is completely bogus because
we've already dereferenced the value in __rht_ptr and operated on it.
This causes potential double readings which could be fatal. The RCU
dereference must occur prior to the comparison in __rht_ptr.
This patch changes the order of RCU dereference so that it is done
first and the result is then fed to __rht_ptr. The RCU marking
changes have been minimised using casts which will be removed in
a follow-up patch.
Fixes: ba6306e3f6 ("rhashtable: Remove RCU marking from...")
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
c3883876d3