If a cifs share is mounted cache=none, internal reads (such as by exec)
will pass a KVEC iterator down from __cifs_readv() to
cifs_send_async_read() which will then call cifs_limit_bvec_subset() upon
it to limit the number of contiguous elements for RDMA purposes. This
doesn't work on non-BVEC iterators, however.
Fix this by extracting a KVEC iterator into a BVEC iterator in
__cifs_readv() (it would be dup'd anyway it async).
This caused the following warning:
WARNING: CPU: 0 PID: 6290 at fs/smb/client/file.c:3549 cifs_limit_bvec_subset+0xe/0xc0
...
Call Trace:
<TASK>
cifs_send_async_read+0x146/0x2e0
__cifs_readv+0x207/0x2d0
__kernel_read+0xf6/0x160
search_binary_handler+0x49/0x210
exec_binprm+0x4a/0x140
bprm_execve.part.0+0xe4/0x170
do_execveat_common.isra.0+0x196/0x1c0
do_execve+0x1f/0x30
Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Acked-by: Bharath SM <bharathsm@microsoft.com>
Tested-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@kernel.org # v6.6~v6.9
Signed-off-by: Sasha Levin <sashal@kernel.org>
David HowellsandGreg Kroah-Hartman
25d6e76639