[PATCH v2] tracing/probes: fix error check in parse_btf_field()
btf_find_struct_member() might return NULL or an error via the ERR_PTR() macro. However, its caller in parse_btf_field() only checks for the NULL condition. Fix this by using IS_ERR() and returning the error up the stack. Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access") Signed-off-by: Carlos López --- v2: added call to trace_probe_log_err() kernel/trace/trace_probe.c | 4 1 file changed, 4 insertions(+) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 5e263c141574..39877c80d6cb 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -554,6 +554,10 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type, anon_offs = 0; field = btf_find_struct_member(ctx->btf, type, fieldname, _offs); + if (IS_ERR(field)) { + trace_probe_log_err(ctx->offset, BAD_BTF_TID); + return PTR_ERR(field); + } if (!field) { trace_probe_log_err(ctx->offset, NO_BTF_FIELD); return -ENOENT; -- 2.35.3
Re: [PATCH] tracing/probes: fix error check in parse_btf_field()
Hi, On 26/5/24 12:17, Masami Hiramatsu (Google) wrote: On Sat, 25 May 2024 20:21:32 +0200 Carlos López wrote: btf_find_struct_member() might return NULL or an error via the ERR_PTR() macro. However, its caller in parse_btf_field() only checks for the NULL condition. Fix this by using IS_ERR() and returning the error up the stack. Thanks for finding it! I think this requires new error message for error_log file. Can you add the log as trace_probe_log_err(ctx->offset, BTF_ERROR); And define BTF_ERROR in ERRORS@kernel/trace/trace_probe.h ? Sounds good, but should we perhaps reuse BAD_BTF_TID? ``` C(BAD_BTF_TID, "Failed to get BTF type info."),\ ``` `btf_find_struct_member()` fails if `type` is not a struct or if it runs OOM while allocating the anon stack, so it seems appropriate. Best, Carlos Thank you, Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access") Signed-off-by: Carlos López --- kernel/trace/trace_probe.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 5e263c141574..5417e9712157 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -554,6 +554,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type, anon_offs = 0; field = btf_find_struct_member(ctx->btf, type, fieldname, _offs); + if (IS_ERR(field)) + return PTR_ERR(field); if (!field) { trace_probe_log_err(ctx->offset, NO_BTF_FIELD); return -ENOENT; -- 2.35.3 -- Carlos López Security Engineer SUSE Software Solutions
[PATCH] tracing/probes: fix error check in parse_btf_field()
btf_find_struct_member() might return NULL or an error via the ERR_PTR() macro. However, its caller in parse_btf_field() only checks for the NULL condition. Fix this by using IS_ERR() and returning the error up the stack. Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access") Signed-off-by: Carlos López --- kernel/trace/trace_probe.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 5e263c141574..5417e9712157 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -554,6 +554,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type, anon_offs = 0; field = btf_find_struct_member(ctx->btf, type, fieldname, _offs); + if (IS_ERR(field)) + return PTR_ERR(field); if (!field) { trace_probe_log_err(ctx->offset, NO_BTF_FIELD); return -ENOENT; -- 2.35.3