From: Omar Sandoval <osan...@fb.com>
When read_addrs() was converted was converted from a nested function to
a normal function, there was a mistake in converting "buffer" from a
closure variable to a parameter: we are checking whether the pointer
argument is NULL, not whether the buffer itself is NULL. This causes a
NULL pointer dereference when we try to use the NULL buffer later.
Fixes: 3bf41d458fb6 ("link_map: Pull read_addrs() into file scope") made
Signed-off-by: Omar Sandoval <osan...@fb.com>
---
libdwfl/ChangeLog | 4 ++++
libdwfl/link_map.c | 2 +-
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index fedf65a4..c57c7708 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,7 @@
+2021-06-09 Omar Sandoval <osan...@fb.com>
+
+ * link_map.c (read_addrs): Fix crash.
+
2021-04-19 Martin Liska <mli...@suse.cz>
* dwfl_frame.c (dwfl_attach_state): Use startswith.
diff --git a/libdwfl/link_map.c b/libdwfl/link_map.c
index 0d8d1c17..1e7d4502 100644
--- a/libdwfl/link_map.c
+++ b/libdwfl/link_map.c
@@ -254,7 +254,7 @@ read_addrs (struct memory_closure *closure,
Dwfl *dwfl = closure->dwfl;
/* Read a new buffer if the old one doesn't cover these words. */
- if (buffer == NULL
+ if (*buffer == NULL
|| vaddr < *read_vaddr
|| vaddr - (*read_vaddr) + nb > *buffer_available)
{
--
2.32.0
