On Tue, Dec 25, 2018 at 01:17:10AM -0600, Kangjie Lu wrote: > check_reg_arg() may fail. This fix inserts checks for its return value. > If check_reg_arg() fails, issues an error message. > > Signed-off-by: Kangjie Lu <k...@umn.edu> > --- > kernel/bpf/verifier.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 51ba84d4d34a..fde91a5c0b5a 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -2619,7 +2619,10 @@ static int check_func_call(struct bpf_verifier_env > *env, struct bpf_insn *insn, > /* after the call registers r0 - r5 were scratched */ > for (i = 0; i < CALLER_SAVED_REGS; i++) { > mark_reg_not_init(env, caller->regs, caller_saved[i]); > - check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK); > + err = check_reg_arg(env, caller_saved[i], DST_OP_NO_MARK); > + if (err) > + verbose(env, > + "check_reg_arg() fails in setting > caller saved regs\n");
Such patch was already posted. These calls cannot fail. I prefer to leave them as-is.