From f3075c2c13b751686921079c8f9e13c6f07b6fc8 Mon Sep 17 00:00:00 2001 From: Josh Law Date: Thu, 12 Mar 2026 19:11:42 +0000 Subject: lib/bootconfig: check bounds before writing in __xbc_open_brace() commit 560f763baa0f2c9a44da4294c06af071405ac46f upstream. The bounds check for brace_index happens after the array write. While the current call pattern prevents an actual out-of-bounds access (the previous call would have returned an error), the write-before-check pattern is fragile and would become a real out-of-bounds write if the error return were ever not propagated. Move the bounds check before the array write so the function is self-contained and safe regardless of caller behavior. Link: https://lore.kernel.org/all/20260312191143.28719-3-objecting@objecting.org/ Fixes: ead1e19ad905 ("lib/bootconfig: Fix a bug of breaking existing tree nodes") Cc: stable@vger.kernel.org Signed-off-by: Josh Law Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Greg Kroah-Hartman --- lib/bootconfig.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bootconfig.c b/lib/bootconfig.c index 31ac39aeac77..0728c4a95249 100644 --- a/lib/bootconfig.c +++ b/lib/bootconfig.c @@ -532,9 +532,9 @@ static char *skip_spaces_until_newline(char *p) static int __init __xbc_open_brace(char *p) { /* Push the last key as open brace */ - open_brace[brace_index++] = xbc_node_index(last_parent); if (brace_index >= XBC_DEPTH_MAX) return xbc_parse_error("Exceed max depth of braces", p); + open_brace[brace_index++] = xbc_node_index(last_parent); return 0; } -- cgit v1.2.3