From 6dd142d9013ca82155d0c069434c60a0d5755ec0 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 20 Sep 2022 14:13:05 -0700 Subject: coredump: Proactively round up to kmalloc bucket size Instead of discovering the kmalloc bucket size _after_ allocation, round up proactively so the allocation is explicitly made for the full size, allowing the compiler to correctly reason about the resulting size of the buffer through the existing __alloc_size() hint. Cc: Alexander Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Kees Cook --- fs/coredump.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/coredump.c') diff --git a/fs/coredump.c b/fs/coredump.c index 7bad7785e8e6..97eaee325251 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -68,7 +68,10 @@ struct core_name { static int expand_corename(struct core_name *cn, int size) { - char *corename = krealloc(cn->corename, size, GFP_KERNEL); + char *corename; + + size = kmalloc_size_roundup(size); + corename = krealloc(cn->corename, size, GFP_KERNEL); if (!corename) return -ENOMEM; @@ -76,7 +79,7 @@ static int expand_corename(struct core_name *cn, int size) if (size > core_name_size) /* racy but harmless */ core_name_size = size; - cn->size = ksize(corename); + cn->size = size; cn->corename = corename; return 0; } -- cgit v1.2.3