selftests/bpf: Test indirect var_off stack access in unpriv mode

Browse source

Test that verifier rejects indirect stack access with variable offset in
unprivileged mode and accepts same code in privileged mode.

Since pointer arithmetics is prohibited in unprivileged mode verifier
should reject the program even before it gets to helper call that uses
variable offset, at the time when that variable offset is trying to be
constructed.

Example of output:
  # ./test_verifier
  ...
  #859/u indirect variable-offset stack access, priv vs unpriv OK
  #859/p indirect variable-offset stack access, priv vs unpriv OK

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

...

This commit is contained in:

Andrey Ignatov 2019-04-03 23:22:40 -07:00 • committed by Daniel Borkmann

parent 088ec26d9c

commit 2c6927dbdc

1 changed files with 27 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

27

tools/testing/selftests/bpf/verifier/var_off.c

View file