[bpf,v2,0/3] Fix local storage helper OOPs

Message

KP Singh Jan. 11, 2021, 9:23 p.m. UTC

It was noted in
https://lore.kernel.org/bpf/CACYkzJ55X8Tp2q4+EFf2hOM_Lysoim1xJY1YdA3k=[e-mail]/T/#t
that the local storage helpers do not handle null owner pointers
correctly. This patch fixes the task and inode storage helpers with a
null check. In order to keep the check explicit, it's kept in the body
of the helpers similar to sk_storage and also fixes a minor typo in
bpf_inode_storage.c [I did not add a fixes and reported tag to the
patch that fixes the typo since it's a non-functional change].

The series also incorporates the example posted by Gilad into the
selftest. The selftest, without the fix reproduces the oops and the
subsequent patch fixes it.

KP Singh (3):
  bpf: update local storage test to check handling of null ptrs
  bpf: local storage helpers should check nullness of owner ptr passed
  bpf: Fix typo in bpf_inode_storage.c

 kernel/bpf/bpf_inode_storage.c                |  9 +-
 kernel/bpf/bpf_task_storage.c                 |  5 +-
 .../bpf/prog_tests/test_local_storage.c       | 96 +++++--------------
 .../selftests/bpf/progs/local_storage.c       | 62 ++++++------
 4 files changed, 71 insertions(+), 101 deletions(-)