Commit f16e6313 authored Nov 11, 2020 by Kaixu Xia Committed by Daniel Borkmann Nov 11, 2020

bpf: Fix unsigned 'datasec_id' compared with zero in check_pseudo_btf_id



The unsigned variable datasec_id is assigned a return value from the call
to check_pseudo_btf_id(), which may return negative error code.

This fixes the following coccicheck warning:

  ./kernel/bpf/verifier.c:9616:5-15: WARNING: Unsigned expression compared with zero: datasec_id > 0

Fixes: eaa6bcb7 ("bpf: Introduce bpf_per_cpu_ptr()")
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Link: https://lore.kernel.org/bpf/1605071026-25906-1-git-send-email-kaixuxia@tencent.com

parent abbaa433

kernel/bpf/verifier.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -9572,12 +9572,13 @@ static int check_pseudo_btf_id(struct bpf_verifier_env *env,
		struct bpf_insn *insn,
		struct bpf_insn_aux_data *aux)
		{
		u32 datasec_id, type, id = insn->imm;
		const struct btf_var_secinfo *vsi;
		const struct btf_type *datasec;
		const struct btf_type *t;
		const char *sym_name;
		bool percpu = false;
		u32 type, id = insn->imm;
		s32 datasec_id;
		u64 addr;
		int i;

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