bpf: Fix tr dereferencing

Asphaltt · anakryiko · commit b724a6418f1f · 2023-09-19T16:41:26.000-07:00
Fix 'tr' dereferencing bug when CONFIG_BPF_JIT is turned off. When CONFIG_BPF_JIT is turned off, 'bpf_trampoline_get()' returns NULL, which is same as the cases when CONFIG_BPF_JIT is turned on. Closes: https://lore.kernel.org/r/202309131936.5Nc8eUD0-lkp@intel.com/ Fixes: f7b12b6 ("bpf: verifier: refactor check_attach_btf_id()") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Leon Hwang <hffilwlqm@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230917153846.88732-1-hffilwlqm@gmail.com
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
@@ -1307,7 +1307,7 @@ static inline int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
 static inline struct bpf_trampoline *bpf_trampoline_get(u64 key,
 							struct bpf_attach_target_info *tgt_info)
 {
-	return ERR_PTR(-EOPNOTSUPP);
+	return NULL;
 }
 static inline void bpf_trampoline_put(struct bpf_trampoline *tr) {}
 #define DEFINE_BPF_DISPATCHER(name)

Original file line number	Diff line number	Diff line change
`@@ -1307,7 +1307,7 @@ static inline int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,`
`1307`	`1307`	`static inline struct bpf_trampoline *bpf_trampoline_get(u64 key,`
`1308`	`1308`	`struct bpf_attach_target_info *tgt_info)`
`1309`	`1309`	`{`
`1310`		`- return ERR_PTR(-EOPNOTSUPP);`
	`1310`	`+ return NULL;`
`1311`	`1311`	`}`
`1312`	`1312`	`static inline void bpf_trampoline_put(struct bpf_trampoline *tr) {}`
`1313`	`1313`	`#define DEFINE_BPF_DISPATCHER(name)`