[Crash-utility] [PATCH] gdb: verify COFF symbol stringtab offset
This is a backport patch from gdb commit 58abdf887821 ("Verify COFF
symbol stringtab offset").
The AddressSanitizer reports a heap-use-after-free error as below:
gdb/coff-pe-read.c:137:27
Add a COFF offset check to fix this issue.
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=30640
Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com>
---
Please see the CVE-2023-39129.
gdb-10.2.patch | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/gdb-10.2.patch b/gdb-10.2.patch
index 7f4b86350bde..98538dc1138b 100644
--- a/gdb-10.2.patch
+++ b/gdb-10.2.patch
@@ -3156,4 +3156,35 @@ exit 0
+ else if (i >= 0 && encoded[i] == '$')
len0 = i;
}
+
+--- gdb-10.2/gdb/coffread.c.orig
++++ gdb-10.2/gdb/coffread.c
+@@ -159,6 +159,7 @@ static long linetab_offset;
+ static unsigned long linetab_size;
+
+ static char *stringtab = NULL;
++static long stringtab_length = 0;
+
+ extern void stabsread_clear_cache (void);
+
+@@ -1297,6 +1298,7 @@ init_stringtab (bfd *abfd, long offset,
gdb::unique_xmalloc_ptr<char> *storage)
+ /* This is in target format (probably not very useful, and not
+ currently used), not host format. */
+ memcpy (stringtab, lengthbuf, sizeof lengthbuf);
++ stringtab_length = length;
+ if (length == sizeof length) /* Empty table -- just the count. */
+ return 0;
+
+@@ -1316,8 +1318,9 @@ getsymname (struct internal_syment *symbol_entry)
+
+ if (symbol_entry->_n._n_n._n_zeroes == 0)
+ {
+- /* FIXME: Probably should be detecting corrupt symbol files by
+- seeing whether offset points to within the stringtab. */
++ if (symbol_entry->_n._n_n._n_offset > stringtab_length)
++ error (_("COFF Error: string table offset (%ld) outside string table
(length %ld)"),
++ symbol_entry->_n._n_n._n_offset, stringtab_length);
+ result = stringtab + symbol_entry->_n._n_n._n_offset;
+ }
+ else
--
2.41.0