ksmbd: prevent out of share access

mainline inclusion
from mainline-5.15-rc3
commit f58eae6c
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I60T7G
CVE: NA

Reference: https://git.kernel.org/torvalds/linux/c/f58eae6c5fa8

-------------------------------

Because of .., files outside the share directory
could be accessed. To prevent this, normalize
the given path and remove all . and ..
components.

In addition to the usual large set of regression tests (smbtorture
and xfstests), ran various tests on this to specifically check
path name validation including libsmb2 tests to verify path
normalization:

 ./examples/smb2-ls-async smb://172.30.1.15/homes2/../
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/../
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/../../
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/../
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/..bar/
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/bar../
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/bar..
 ./examples/smb2-ls-async smb://172.30.1.15/homes2/foo/bar../../../../



Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>