When compiled with address sanitizer, a couple of errors were reported
on pahole BTF encoding:
* A memory leak of strdup(func->alias), due to unchecked
reassignment.
* A read of uninitialized memory in gobuffer__sort or bsearch in
case btf_funcs gobuffer is empty.
Used compiler flags:
-fsanitize=undefined,address
-fsanitize-recover=address
-fno-omit-frame-pointer
v1: https://lore.kernel.org/dwarves/20241213233205.633927-1-ihor.solodrai@xxxxx/
Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxx>
---
btf_encoder.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/btf_encoder.c b/btf_encoder.c
index 3754884..fbc9509 100644
--- a/btf_encoder.c
+++ b/btf_encoder.c
@@ -1794,7 +1794,8 @@ static int btf_encoder__collect_btf_funcs(struct btf_encoder *encoder, struct go
}
/* Now that we've collected funcs, sort them by name */
- gobuffer__sort(funcs, sizeof(struct btf_func), btf_func_cmp);
+ if (gobuffer__nr_entries(funcs) > 0)
+ gobuffer__sort(funcs, sizeof(struct btf_func), btf_func_cmp);
err = 0;
out:
@@ -1954,6 +1955,11 @@ static int btf_encoder__tag_kfuncs(struct btf_encoder *encoder)
goto out;
}
+ if (gobuffer__nr_entries(&btf_funcs) == 0) {
+ err = 0;
+ goto out;
+ }
+
/* First collect all kfunc set ranges.
*
* Note we choose not to sort these ranges and accept a linear
@@ -2607,7 +2613,8 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu, struct co
", has optimized-out parameters" :
fn->proto.unexpected_reg ? ", has unexpected register use by params" :
"");
- func->alias = strdup(name);
+ if (!func->alias)
+ func->alias = strdup(name);
}
}
} else {
--
2.47.1
