patch 9.0.2142: [security]: stack-buffer-overflow in option callback functionsv9.0.2142

Problem:  [security]: stack-buffer-overflow in option callback functions
Solution: pass size of errbuf down the call stack, use snprintf()
          instead of sprintf()

We pass the error buffer down to the option callback functions, but in
some parts of the code, we simply use sprintf(buf) to write into the error
buffer, which can overflow.

So let's pass down the length of the error buffer and use sprintf(buf, size)
instead.

Reported by @henices, thanks!

Signed-off-by: Christian Brabandt <cb@256bit.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/map.c b/src/map.c
index 5988445bd1..98785e722c 100644
--- a/src/map.c
+++ b/src/map.c
@@ -3114,7 +3114,7 @@ did_set_langmap(optset_T *args UNUSED)
 		    {
 			if (p[0] != ',')
 			{
-			    sprintf(args->os_errbuf,
+			    snprintf(args->os_errbuf, args->os_errbuflen,
 				    _(e_langmap_extra_characters_after_semicolon_str),
 				    p);
 			    return args->os_errbuf;