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| author | Andrii Nakryiko <andrii@kernel.org> | 2024-01-03 10:37:57 -0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-01-03 10:37:57 -0800 |
| commit | a640de4cf9fec0caf43ccb7404ec9f0fde9a6a65 (patch) | |
| tree | d58e59ba6536fc754d8aed14bd7ef6a2a3fe2be0 /kernel | |
| parent | 2ab1efad60ad119b616722b81eeb73060728028c (diff) | |
| parent | 72187506de4f19fcc8ae63a2b2f36d75e5259d9d (diff) | |
Merge branch 'bpf-simplify-checking-size-of-helper-accesses'
Andrei Matei says:
====================
bpf: Simplify checking size of helper accesses
v3->v4:
- kept only the minimal change, undoing debatable changes (Andrii)
- dropped the second patch from before, with changes to the error
message (Andrii)
- extracted the new test into a separate patch (Andrii)
- added Acked by Andrii
v2->v3:
- split the error-logging function to a separate patch (Andrii)
- make the error buffers smaller (Andrii)
- include size of memory region for PTR_TO_MEM (Andrii)
- nits from Andrii and Eduard
v1->v2:
- make the error message include more info about the context of the
zero-sized access (Andrii)
====================
Link: https://lore.kernel.org/r/20231221232225.568730-1-andreimatei1@gmail.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a376eb609c41..d4e31f61de0e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7279,12 +7279,10 @@ static int check_mem_size_reg(struct bpf_verifier_env *env, return -EACCES; } - if (reg->umin_value == 0) { - err = check_helper_mem_access(env, regno - 1, 0, - zero_size_allowed, - meta); - if (err) - return err; + if (reg->umin_value == 0 && !zero_size_allowed) { + verbose(env, "R%d invalid zero-sized read: u64=[%lld,%lld]\n", + regno, reg->umin_value, reg->umax_value); + return -EACCES; } if (reg->umax_value >= BPF_MAX_VAR_SIZ) { |