From: Mark Wielaard <mark@klomp.org>
Date: Sat, 25 Apr 2020 23:41:27 +0000 (+0200)
Subject: libdw: Call Dwarf oom_handler() when malloc fails in __libdw_alloc_tail.
X-Git-Tag: elfutils-0.180~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5436c7529dd9b24f62e3df10e30d5da53da16efd;p=thirdparty%2Felfutils.git

libdw: Call Dwarf oom_handler() when malloc fails in __libdw_alloc_tail.

GCC10 -fanalyzer found a possibly-NULL dereference after a failed
malloc in __libdw_alloc_tail. In this case we should call the Dwarf
oom_handler as is done in other places where an essential malloc
call fails. The oom_handler cannot return and will likely just abort.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 39730fbc7..75fc8f062 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2020-04-25  Mark Wielaard  <mark@klomp.org>
+
+	* libdw_alloc.c (__libdw_alloc_tail): Call Dwarf oom_handler()
+	when malloc fails.
+
 2020-04-17  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_begin_elf.c (check_section): Handle .gnu.debuglto_ prefix.
diff --git a/libdw/libdw_alloc.c b/libdw/libdw_alloc.c
index e0281a3df..b3e533434 100644
--- a/libdw/libdw_alloc.c
+++ b/libdw/libdw_alloc.c
@@ -87,6 +87,11 @@ __libdw_alloc_tail (Dwarf *dbg)
   if (result == NULL)
     {
       result = malloc (dbg->mem_default_size);
+      if (result == NULL)
+	{
+	  pthread_rwlock_unlock (&dbg->mem_rwl);
+	  dbg->oom_handler();
+	}
       result->size = dbg->mem_default_size
                      - offsetof (struct libdw_memblock, mem);
       result->remaining = result->size;