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authorJohn Fastabend <john.fastabend@gmail.com>2020-03-30 14:36:59 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-03-30 15:00:30 -0700
commitfa123ac022e425becce11f1a6c7ee4d283f75a90 (patch)
tree60ef9edb0194ededb767393fdc2c9278d5569dd0 /kernel
parent3f50f132d8400e129fc9eb68b5020167ef80a244 (diff)
bpf: Verifier, refine 32bit bound in do_refine_retval_range
Further refine return values range in do_refine_retval_range by noting these are int return types (We will assume here that int is a 32-bit type). Two reasons to pull this out of original patch. First it makes the original fix impossible to backport. And second I've not seen this as being problematic in practice unlike the other case. Fixes: 849fa50662fbc ("bpf/verifier: refine retval R0 state for bpf_get_stack helper") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/158560421952.10843.12496354931526965046.stgit@john-Precision-5820-Tower
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/verifier.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1c60d001bb46..04c6630cc18f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4335,6 +4335,7 @@ static void do_refine_retval_range(struct bpf_reg_state *regs, int ret_type,
return;
ret_reg->smax_value = meta->msize_max_value;
+ ret_reg->s32_max_value = meta->msize_max_value;
__reg_deduce_bounds(ret_reg);
__reg_bound_offset(ret_reg);
__update_reg_bounds(ret_reg);