[ Upstream commit 629e052d0c ]
If the hfi1 module is loaded with HFI1_CAP_SDMA off, a call to
hfi1_write_iter() will dereference a NULL pointer and panic. A typical
stack frame is:
sdma_select_user_engine [hfi1]
hfi1_user_sdma_process_request [hfi1]
hfi1_write_iter [hfi1]
do_iter_readv_writev
do_iter_write
vfs_writev
do_writev
do_syscall_64
The fix is to test for SDMA in hfi1_write_iter() and fail the I/O with
EINVAL.
Link: https://lore.kernel.org/r/20220520183706.48973.79803.stgit@awfm-01.cornelisnetworks.com
Signed-off-by: Douglas Miller <doug.miller@cornelisnetworks.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
33794e8e9b