Pointed out by gcc 12 with -Wuse-after-free=3
In function ‘free_section’
asm_end.c:552:17: error: pointer ‘data’ used after ‘free’
[-Werror=use-after-free]
552 | while (oldp != scnp->content);
| ~~~~~^~~~~~~~~~~~~~~~
asm_end.c:550:9: note: call to ‘free’ here
550 | free (oldp);
| ^~~~~~~~~~~
Fix by freeing scnp->content last.
Signed-off-by: Mark Wielaard <[email protected]>
---
libasm/ChangeLog | 4 ++++
libasm/asm_end.c | 18 ++++++++++--------
2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/libasm/ChangeLog b/libasm/ChangeLog
index a12d14b3..f23d5914 100644
--- a/libasm/ChangeLog
+++ b/libasm/ChangeLog
@@ -1,3 +1,7 @@
+2023-02-17 Mark Wielaard <[email protected]>
+
+ * asm_end.c (free_section): free scnp->content last.
+
2022-12-20 Mark Wielaard <[email protected]>
* disasm_begin.c: Include libeblP.h.
diff --git a/libasm/asm_end.c b/libasm/asm_end.c
index c06d2366..29165ac4 100644
--- a/libasm/asm_end.c
+++ b/libasm/asm_end.c
@@ -541,16 +541,18 @@ free_section (AsmScn_t *scnp)
if (scnp->subnext != NULL)
free_section (scnp->subnext);
+ /* This is a circular single linked list. */
struct AsmData *data = scnp->content;
if (data != NULL)
- do
- {
- oldp = data;
- data = data->next;
- free (oldp);
- }
- while (oldp != scnp->content);
-
+ {
+ while (data != scnp->content)
+ {
+ oldp = data;
+ data = data->next;
+ free (oldp);
+ }
+ free (scnp->content);
+ }
free (scnp);
}
--
2.39.1
