From e6b133311a7a5a618b48c6f38e3c3bb9e9a395c9 Mon Sep 17 00:00:00 2001 From: eillon Date: Mon, 14 Feb 2022 15:35:28 +0800 Subject: [PATCH] seabios: add check to avoid dereference NULL pointer alloc_find_lowest() may return NULL, check it. Signed-off-by: eillon --- roms/seabios/src/malloc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/roms/seabios/src/malloc.c b/roms/seabios/src/malloc.c index 5827a6523..99fa3b7e0 100644 --- a/roms/seabios/src/malloc.c +++ b/roms/seabios/src/malloc.c @@ -544,10 +544,12 @@ malloc_prepboot(void) // Clear unused f-seg ram. struct allocinfo_s *info = alloc_find_lowest(&ZoneFSeg); - u32 size = info->range_end - info->range_start; - memset(memremap(info->range_start, size), 0, size); - dprintf(1, "Space available for UMB: %x-%x, %x-%x\n" - , RomEnd, base, info->range_start, info->range_end); + if (info) { + u32 size = info->range_end - info->range_start; + memset(memremap(info->range_start, size), 0, size); + dprintf(1, "Space available for UMB: %x-%x, %x-%x\n" + , RomEnd, base, info->range_start, info->range_end); + } // We should not give back unused high ram, to support some special // guest OS, like oracle linux series. -- 2.27.0