[ Upstream commit 9ffed254d938c9e99eb7761c7f739294c84e0367 ] Memory buffer used for reading out data from hardware system area is not protected against concurrent access. Reported-by: Matthew Wilcox <willy@infradead.org> Fixes: 411ed3225733 ("[S390] zfcpdump support.") Acked-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Link: https://lore.kernel.org/r/e68137f0f9a0d2558f37becc20af18e2939934f6.1658206891.git.agordeev@linux.ibm.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>