diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 20ffc609259c..15ddc4292bc0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1249,6 +1249,21 @@ static void __reg_bound_offset(struct bpf_reg_state *reg) reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off); } +static void reg_bounds_sync(struct bpf_reg_state *reg) +{ + /* We might have learned new bounds from the var_off. */ + __update_reg_bounds(reg); + /* We might have learned something about the sign bit. */ + __reg_deduce_bounds(reg); + /* We might have learned some bits from the bounds. */ + __reg_bound_offset(reg); + /* Intersecting with the old var_off might have improved our bounds + * slightly, e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc), + * then new var_off is (0; 0x7f...fc) which improves our umax. + */ + __update_reg_bounds(reg); +} + static bool __reg32_bound_s64(s32 a) { return a >= 0 && a <= S32_MAX; @@ -1290,16 +1305,8 @@ static void __reg_combine_32_into_64(struct bpf_reg_state *reg) * so they do not impact tnum bounds calculation. */ __mark_reg64_unbounded(reg); - __update_reg_bounds(reg); } - - /* Intersecting with the old var_off might have improved our bounds - * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc), - * then new var_off is (0; 0x7f...fc) which improves our umax. - */ - __reg_deduce_bounds(reg); - __reg_bound_offset(reg); - __update_reg_bounds(reg); + reg_bounds_sync(reg); } static bool __reg64_bound_s32(s64 a) @@ -1315,7 +1322,6 @@ static bool __reg64_bound_u32(u64 a) static void __reg_combine_64_into_32(struct bpf_reg_state *reg) { __mark_reg32_unbounded(reg); - if (__reg64_bound_s32(reg->smin_value) && __reg64_bound_s32(reg->smax_value)) { reg->s32_min_value = (s32)reg->smin_value; reg->s32_max_value = (s32)reg->smax_value; @@ -1324,14 +1330,7 @@ static void __reg_combine_64_into_32(struct bpf_reg_state *reg) reg->u32_min_value = (u32)reg->umin_value; reg->u32_max_value = (u32)reg->umax_value; } - - /* Intersecting with the old var_off might have improved our bounds - * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc), - * then new var_off is (0; 0x7f...fc) which improves our umax. - */ - __reg_deduce_bounds(reg); - __reg_bound_offset(reg); - __update_reg_bounds(reg); + reg_bounds_sync(reg); } /* Mark a register as having a completely unknown (scalar) value. */ @@ -5230,9 +5229,7 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type, ret_reg->s32_max_value = meta->msize_max_value; ret_reg->smin_value = -MAX_ERRNO; ret_reg->s32_min_value = -MAX_ERRNO; - __reg_deduce_bounds(ret_reg); - __reg_bound_offset(ret_reg); - __update_reg_bounds(ret_reg); + reg_bounds_sync(ret_reg); } static int @@ -6197,11 +6194,7 @@ reject: if (!check_reg_sane_offset(env, dst_reg, ptr_reg->type)) return -EINVAL; - - __update_reg_bounds(dst_reg); - __reg_deduce_bounds(dst_reg); - __reg_bound_offset(dst_reg); - + reg_bounds_sync(dst_reg); if (sanitize_check_bounds(env, insn, dst_reg) < 0) return -EACCES; if (sanitize_needed(opcode)) { @@ -6939,10 +6932,7 @@ static int adjust_scalar_min_max_vals(struct bpf_verifier_env *env, /* ALU32 ops are zero extended into 64bit register */ if (alu32) zext_32_to_64(dst_reg); - - __update_reg_bounds(dst_reg); - __reg_deduce_bounds(dst_reg); - __reg_bound_offset(dst_reg); + reg_bounds_sync(dst_reg); return 0; } @@ -7131,10 +7121,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) insn->dst_reg); } zext_32_to_64(dst_reg); - - __update_reg_bounds(dst_reg); - __reg_deduce_bounds(dst_reg); - __reg_bound_offset(dst_reg); + reg_bounds_sync(dst_reg); } } else { /* case: R = imm @@ -7693,21 +7680,8 @@ static void __reg_combine_min_max(struct bpf_reg_state *src_reg, dst_reg->smax_value); src_reg->var_off = dst_reg->var_off = tnum_intersect(src_reg->var_off, dst_reg->var_off); - /* We might have learned new bounds from the var_off. */ - __update_reg_bounds(src_reg); - __update_reg_bounds(dst_reg); - /* We might have learned something about the sign bit. */ - __reg_deduce_bounds(src_reg); - __reg_deduce_bounds(dst_reg); - /* We might have learned some bits from the bounds. */ - __reg_bound_offset(src_reg); - __reg_bound_offset(dst_reg); - /* Intersecting with the old var_off might have improved our bounds - * slightly. e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc), - * then new var_off is (0; 0x7f...fc) which improves our umax. - */ - __update_reg_bounds(src_reg); - __update_reg_bounds(dst_reg); + reg_bounds_sync(src_reg); + reg_bounds_sync(dst_reg); } static void reg_combine_min_max(struct bpf_reg_state *true_src,