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selftests/bpf: Adjust verifier_map_ptr for the map's excl field

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Adding the u32 excl field at offset 32 of struct bpf_map right after the
sha[SHA256_DIGEST_SIZE] hash shifts the ops pointer from offset 32 to 40.
Therefore, fix up the test case.

  # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_map_ptr
  [...]
  #637/1   verifier_map_ptr/bpf_map_ptr: read with negative offset rejected:OK
  #637/2   verifier_map_ptr/bpf_map_ptr: read with negative offset rejected @unpriv:OK
  #637/3   verifier_map_ptr/bpf_map_ptr: write rejected:OK
  #637/4   verifier_map_ptr/bpf_map_ptr: write rejected @unpriv:OK
  #637/5   verifier_map_ptr/bpf_map_ptr: read non-existent field rejected:OK
  #637/6   verifier_map_ptr/bpf_map_ptr: read non-existent field rejected @unpriv:OK
  #637/7   verifier_map_ptr/bpf_map_ptr: read ops field accepted:OK
  #637/8   verifier_map_ptr/bpf_map_ptr: read ops field accepted @unpriv:OK
  [...]
  Summary: 2/18 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: KP Singh <kpsingh@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260601150248.394863-7-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
KP Singh 2026-06-01 17:02:47 +02:00 committed by Alexei Starovoitov
parent 60214435b3
commit 38498c0eba
1 changed files with 5 additions and 3 deletions
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8
tools/testing/selftests/bpf/progs/verifier_map_ptr.c
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@ -70,13 +70,15 @@ __naked void bpf_map_ptr_write_rejected(void)
: __clobber_all);
}
/* The first element of struct bpf_map is a SHA256 hash of 32 bytes, accessing
* into this array is valid. The opts field is now at offset 33.
/*
* struct bpf_map starts with the SHA256 hash sha[32] at offset 0 (a readable
* byte array), followed by the u32 excl field at offset 32. Reading a u32 at
* offset 33 runs past the end of excl and is rejected.
*/
SEC("socket")
__description("bpf_map_ptr: read non-existent field rejected")
__failure
__msg("cannot access ptr member ops with moff 32 in struct bpf_map with off 33 size 4")
__msg("access beyond the end of member excl (mend:36) in struct bpf_map with off 33 size 4")
__failure_unpriv
__msg_unpriv("access is allowed only to CAP_PERFMON and CAP_SYS_ADMIN")
__flag(BPF_F_ANY_ALIGNMENT)