Re: [PATCH bpf 1/8] bpf: don't infer non-NULL from a pointer with an unbounded offset

[patchwork-bot+netdevbpf@kernel.org]

Hello:

This series was applied to bpf/bpf.git (master)
by Kumar Kartikeya Dwivedi <memxor@gmail.com>:

On Fri,  4 Sep 2026 01:33:18 -0700 you wrote:
> reg_not_null() decides that a register holds a non-NULL value by
> looking at its type alone. For pointer types that allow arithmetic the
> type only guarantees a non-NULL base, in case of an unbound offset
> the runtime offset value might still add up to NULL.
> Consider the followng program:
> 
>   r6 = bpf_map_lookup_elem(map, &0);  /* present */
>   if (r6 == 0) return 0;
>   r7 = bpf_map_lookup_elem(map, &1);  /* absent, NULL at runtime */
>   r8 = r7;
>   r8 -= r6;     /* pointer - pointer: unknown scalar, -r6 */
>   r8 <<= 1;
>   r8 >>= 1;     /* any non-negative offset is accepted by */
>                 /* check_reg_sane_offset_ptr() */
>   r6 += r8;     /* verifier: map value;    runtime: zero  */
>   if (r7 != r6) return 0;
>   *(u8 *)(r7 + 0);  /* r7 is inferred non-NULL, both are zero */
> 
> [...]

Here is the summary with links:
  - [bpf,1/8] bpf: don't infer non-NULL from a pointer with an unbounded offset
    https://git.kernel.org/bpf/bpf/c/67b529f521a6
  - [bpf,2/8] selftests/bpf: no non-NULL inference from unbounded offset pointers
    https://git.kernel.org/bpf/bpf/c/6752b90ccfb3
  - [bpf,3/8] bpf: don't resurrect a scalar id dropped by collect_linked_regs()
    https://git.kernel.org/bpf/bpf/c/73a98f96811e
  - [bpf,4/8] selftests/bpf: check the linked regs cap for the compared register
    https://git.kernel.org/bpf/bpf/c/bc412b3fb185
  - [bpf,5/8] bpf: don't predict JMP32 pointer vs zero comparisons
    https://git.kernel.org/bpf/bpf/c/e51179a4e098
  - [bpf,6/8] selftests/bpf: check that JMP32 pointer vs zero jumps are not predicted
    https://git.kernel.org/bpf/bpf/c/836b2fe544a5
  - [bpf,7/8] bpf: mark the zero register precise for a register-form NULL check
    https://git.kernel.org/bpf/bpf/c/6aed0134d3cd
  - [bpf,8/8] selftests/bpf: no non-NULL inference from an imprecise zero register
    https://git.kernel.org/bpf/bpf/c/6b31560c6bc1

You are awesome, thank you!
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