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bpf: Check for helper calls in check_subprogs()

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The condition src_reg != BPF_PSEUDO_CALL && imm == BPF_FUNC_tail_call
may be satisfied by a kfunc call. This would lead to unnecessarily
setting has_tail_call. Use src_reg == 0 instead.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230220163756.753713-1-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Ilya Leoshkevich 2023-02-20 17:37:56 +01:00 committed by Alexei Starovoitov
parent bb035ef0cc
commit df2ccc180a
1 changed files with 2 additions and 2 deletions
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4
kernel/bpf/verifier.c
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@ -2479,8 +2479,8 @@ static int check_subprogs(struct bpf_verifier_env *env)
u8 code = insn[i].code;
if (code == (BPF_JMP | BPF_CALL) &&
insn[i].imm == BPF_FUNC_tail_call &&
insn[i].src_reg != BPF_PSEUDO_CALL)
insn[i].src_reg == 0 &&
insn[i].imm == BPF_FUNC_tail_call)
subprog[cur_subprog].has_tail_call = true;
if (BPF_CLASS(code) == BPF_LD &&
(BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND))