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| author | Eduard Zingerman <eddyz87@gmail.com> | 2025-07-05 02:03:48 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-07-07 18:25:06 +0300 |
| commit | 2d5c91e1cc14c3511d163ac36ee869ecf3a29cc2 (patch) | |
| tree | ed64783a3c0c40d6449ef7ccd0218e72f4483a72 /tools/testing | |
| parent | b9d44bc9fd30550052d0854d71b0c0731dc9f053 (diff) | |
| download | linux-2d5c91e1cc14c3511d163ac36ee869ecf3a29cc2.tar.xz | |
bpf: rdonly_untrusted_mem for btf id walk pointer leafs
When processing a load from a PTR_TO_BTF_ID, the verifier calculates
the type of the loaded structure field based on the load offset.
For example, given the following types:
struct foo {
struct foo *a;
int *b;
} *p;
The verifier would calculate the type of `p->a` as a pointer to
`struct foo`. However, the type of `p->b` is currently calculated as a
SCALAR_VALUE.
This commit updates the logic for processing PTR_TO_BTF_ID to instead
calculate the type of p->b as PTR_TO_MEM|MEM_RDONLY|PTR_UNTRUSTED.
This change allows further dereferencing of such pointers (using probe
memory instructions).
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250704230354.1323244-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/linked_list.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/linked_list.c b/tools/testing/selftests/bpf/prog_tests/linked_list.c index 5266c7022863..14c5a7ef0e87 100644 --- a/tools/testing/selftests/bpf/prog_tests/linked_list.c +++ b/tools/testing/selftests/bpf/prog_tests/linked_list.c @@ -72,7 +72,7 @@ static struct { { "new_null_ret", "R0 invalid mem access 'ptr_or_null_'" }, { "obj_new_acq", "Unreleased reference id=" }, { "use_after_drop", "invalid mem access 'scalar'" }, - { "ptr_walk_scalar", "type=scalar expected=percpu_ptr_" }, + { "ptr_walk_scalar", "type=rdonly_untrusted_mem expected=percpu_ptr_" }, { "direct_read_lock", "direct access to bpf_spin_lock is disallowed" }, { "direct_write_lock", "direct access to bpf_spin_lock is disallowed" }, { "direct_read_head", "direct access to bpf_list_head is disallowed" }, |