[bpf,v4,0/3] Fix kprobe_multi interface issues for 5.18

Message

Eugene Syromiatnikov May 19, 2022, 6:13 p.m. UTC

Hello.

While [1] seems to require additional work[2] due to changes
in the interface (and it has already been re-targeted for bpf-next),
I would like to ask to consider the following three patches, that fix
possible out-of-bounds write, properly disable the interface
for 32-bit compat user space, and prepare the libbpf interface change,
for the 5.18 release.  Thank you.

[1] https://lore.kernel.org/lkml/[e-mail]/
[2] https://lore.kernel.org/lkml/YoTXiAk1EpZ0rLKE@krava/i

v4:
 - Added additional size checks for INT_MAX, as suggested by Yonghong
   Song
 - Added the third patch for the user space kprobe_multi.addrs type
   change, split from the 4th bpf-next patch, as suggested by Yonghong
   Song and Andrii Nakryiko

v3: https://lore.kernel.org/lkml/[e-mail]/
 - Split out patches for 5.18
 - Removed superfluous size assignments after overflow_mul_check,
   as suggested by Yonghong Song

v2: https://lore.kernel.org/lkml/[e-mail]/
 - Fixed the isses reported by CI

v1: https://lore.kernel.org/lkml/[e-mail]/

Eugene Syromiatnikov (3):
  bpf_trace: check size for overflow in bpf_kprobe_multi_link_attach
  bpf_trace: bail out from bpf_kprobe_multi_link_attach when in compat
  libbpf, selftests/bpf: pass array of u64 values in kprobe_multi.addrs

 kernel/trace/bpf_trace.c                                  | 15 +++++++++------
 tools/lib/bpf/bpf.h                                       |  2 +-
 tools/lib/bpf/libbpf.c                                    |  8 ++++----
 tools/lib/bpf/libbpf.h                                    |  2 +-
 tools/testing/selftests/bpf/prog_tests/bpf_cookie.c       |  2 +-
 .../testing/selftests/bpf/prog_tests/kprobe_multi_test.c  |  8 ++++----
 6 files changed, 20 insertions(+), 17 deletions(-)

Comments

Alexei Starovoitov May 20, 2022, 10:35 p.m. UTC | #1

On Thu, May 19, 2022 at 11:14 AM Eugene Syromiatnikov <[e-mail]> wrote:
>
> Hello.
>
> While [1] seems to require additional work[2] due to changes
> in the interface (and it has already been re-targeted for bpf-next),
> I would like to ask to consider the following three patches, that fix
> possible out-of-bounds write, properly disable the interface
> for 32-bit compat user space, and prepare the libbpf interface change,
> for the 5.18 release.  Thank you.

5.19 is imminent. All fixes should go into bpf-next and backported later.