BSD socket sendmsg() parameters were not verified in usermode

[jukkar]

Fixes #25702

[zephyrbot]

All checks passed.

checkpatch (informational only, not a failure)

-:154: WARNING:LONG_LINE: line over 80 characters
#154: FILE: tests/net/socket/udp/src/main.c:930:
+			 ztest_user_unit_test(test_v4_sendmsg_recvfrom_connected),

-:156: WARNING:LONG_LINE: line over 80 characters
#156: FILE: tests/net/socket/udp/src/main.c:932:
+			 ztest_user_unit_test(test_v6_sendmsg_recvfrom_connected),

- total: 0 errors, 2 warnings, 143 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Your patch has style problems, please review.

NOTE: Ignored message types: AVOID_EXTERNS BRACES CONFIG_EXPERIMENTAL CONST_STRUCT DATE_TIME FILE_PATH_CHANGES MINMAX NETWORKING_BLOCK_COMMENT_STYLE PRINTK_WITHOUT_KERN_LEVEL SPDX_LICENSE_TAG SPLIT_STRING VOLATILE

NOTE: If any of the errors are false positives, please report
      them to the maintainers.

Tip: The bot edits this comment instead of posting a new one, so you can check the comment's history to see earlier messages.

[andrewboie]

msg is a pointer to user memory, need to use z_user_from_copy()

[jukkar]

Yep , and we need to validate the socket descriptor too.

Edit: I will fix these issues after #25804 is merged.
Edit2: The sock will be validated automatically by #25804 so no need to do anything special here. Will send a new version.

[jukkar]

Updated according to comments.