bpf: handle 32-bit zext during constant blinding

Since BPF constant blinding is performed after the verifier pass, the
ALU32 instructions inserted for doubleword immediate loads don't have a
corresponding zext instruction. This is causing a kernel oops on powerpc
and can be reproduced by running 'test_cgroup_storage' with
bpf_jit_harden=2.

Fix this by emitting BPF_ZEXT during constant blinding if
prog->aux->verifier_zext is set.

Fixes: a4b1d3c1ddf6cb ("bpf: verifier: insert zero extension according to analysis result")
Reported-by: Michael Ellerman <[email protected]>
Signed-off-by: Naveen N. Rao <[email protected]>
Reviewed-by: Jiong Wang <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>

0 files changed, 0 insertions, 0 deletions