patch 9.1.0648: [security] double-free in dialog_changed()
Problem: [security] double-free in dialog_changed()
(SuyueGuo)
Solution: Only clear pointer b_sfname pointer, if it is different
than the b_ffname pointer. Don't try to free b_fname,
set it to NULL instead.
fixes: #15403
Github Advisory:
https://github.com/vim/vim/security/advisories/GHSA-46pw-v7qw-xc2f
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index ce30b8d..0d76b3b 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -197,9 +197,11 @@
// restore to empty when write failed
if (empty_bufname)
{
- VIM_CLEAR(buf->b_fname);
+ // prevent double free
+ if (buf->b_sfname != buf->b_ffname)
+ VIM_CLEAR(buf->b_sfname);
+ buf->b_fname = NULL;
VIM_CLEAR(buf->b_ffname);
- VIM_CLEAR(buf->b_sfname);
unchanged(buf, TRUE, FALSE);
}
}
diff --git a/src/testdir/crash/dialog_changed_uaf b/src/testdir/crash/dialog_changed_uaf
new file mode 100644
index 0000000..e37d18d
--- /dev/null
+++ b/src/testdir/crash/dialog_changed_uaf
Binary files differ
diff --git a/src/testdir/test_crash.vim b/src/testdir/test_crash.vim
index 29061aa..9aef245 100644
--- a/src/testdir/test_crash.vim
+++ b/src/testdir/test_crash.vim
@@ -196,6 +196,12 @@
call term_sendkeys(buf, args)
call TermWait(buf, 50)
+ let file = 'crash/dialog_changed_uaf'
+ let cmn_args = "%s -u NONE -i NONE -n -e -s -S %s -c ':qa!'\<cr>"
+ let args = printf(cmn_args, vim, file)
+ call term_sendkeys(buf, args)
+ call TermWait(buf, 150)
+
" clean up
exe buf .. "bw!"
bw!
diff --git a/src/version.c b/src/version.c
index 0e49ebd..3ca6001 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 648,
+/**/
647,
/**/
646,