From abfa13ebe92d81aaf66669c428d767847b577453 Mon Sep 17 00:00:00 2001 From: Christian Brabandt Date: Thu, 30 Nov 2023 11:32:18 +0100 Subject: patch 9.0.2143: [security]: buffer-overflow in ex_substitute Problem: [security]: buffer-overflow in ex_substitute Solution: clear memory after allocating When allocating the new_start pointer in ex_substitute() the memory pointer points to some garbage that the following for loop in ex_cmds.c:4743 confuses and causes it to accessing the new_start pointer beyond it's size, leading to a buffer-overlow. So fix this by using alloc_clear() instead of alloc(), which will clear the memory by NUL and therefore cause the loop to terminate correctly. Reported by @henices, thanks! closes: #13596 Signed-off-by: Christian Brabandt --- src/ex_cmds.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/ex_cmds.c') diff --git a/src/ex_cmds.c b/src/ex_cmds.c index a08682b071..e311fa8e7a 100644 --- a/src/ex_cmds.c +++ b/src/ex_cmds.c @@ -4650,7 +4650,7 @@ ex_substitute(exarg_T *eap) * too many calls to alloc()/free()). */ new_start_len = needed_len + 50; - if ((new_start = alloc(new_start_len)) == NULL) + if ((new_start = alloc_clear(new_start_len)) == NULL) goto outofmem; *new_start = NUL; new_end = new_start; @@ -4667,7 +4667,7 @@ ex_substitute(exarg_T *eap) if (needed_len > (int)new_start_len) { new_start_len = needed_len + 50; - if ((p1 = alloc(new_start_len)) == NULL) + if ((p1 = alloc_clear(new_start_len)) == NULL) { vim_free(new_start); goto outofmem; -- cgit v1.2.3