From: Mark Wielaard <mark@klomp.org>
Date: Sat, 9 May 2020 01:41:56 +0000 (+0200)
Subject: libelf: Check __gelf_getehdr_rdlock call doesn't fail in elf_getdata.
X-Git-Tag: elfutils-0.180~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=59587b33d472ee809250ffba77e38030939fc519;p=thirdparty%2Felfutils.git

libelf: Check __gelf_getehdr_rdlock call doesn't fail in elf_getdata.

GCC10 -fanalyzer with -flto notices __gelf_getehdr_rdlock can fail
and that the result of the call in __libelf_set_rawdata_wrlock isn't
checked, which can cause a dereference of NULL.

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

diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index 56f5354c5..fcea8aa90 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,3 +1,8 @@
+2020-05-08  Mark Wielaard  <mark@klomp.org>
+
+	* elf_getdata.c (__libelf_set_rawdata_wrlock): Check
+	__gelf_getehdr_rdlock return value.
+
 2020-04-25  Mark Wielaard  <mark@klomp.org>
 
 	* elf_compress.c (__libelf_compress): Remove free (out_buf).
diff --git a/libelf/elf_getdata.c b/libelf/elf_getdata.c
index 40fe16945..0d8f8d2ee 100644
--- a/libelf/elf_getdata.c
+++ b/libelf/elf_getdata.c
@@ -271,6 +271,8 @@ __libelf_set_rawdata_wrlock (Elf_Scn *scn)
 	{
 	  GElf_Ehdr ehdr_mem;
 	  GElf_Ehdr *ehdr = __gelf_getehdr_rdlock (elf, &ehdr_mem);
+	  if (unlikely (ehdr == NULL))
+	    return 1;
 	  entsize = SH_ENTSIZE_HASH (ehdr);
 	}
       else