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| author | John Fastabend <john.fastabend@gmail.com> | 2020-03-30 23:36:59 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-31 00:00:30 +0200 |
| commit | fa123ac022e425becce11f1a6c7ee4d283f75a90 (patch) | |
| tree | 60ef9edb0194ededb767393fdc2c9278d5569dd0 /kernel | |
| parent | bpf: Verifier, do explicit ALU32 bounds tracking (diff) | |
| download | linux-fa123ac022e425becce11f1a6c7ee4d283f75a90.tar.xz linux-fa123ac022e425becce11f1a6c7ee4d283f75a90.zip | |
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.c | 1 |
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); |