diff mbox series

[15/95] lib/stackdepot.c: use flex_array_size() helper in memcpy()

Message ID 20201216044307.Qzi6xASDs%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/95] mm: fix a race on nr_swap_pages | expand

Commit Message

Andrew Morton Dec. 16, 2020, 4:43 a.m. UTC 
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: lib/stackdepot.c: use flex_array_size() helper in memcpy()

Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.

This helper offers defense-in-depth against potential integer overflows,
while at the same time makes it explicitly clear that we are dealing with
a flexible array member.

Link: https://lkml.kernel.org/r/186e37fe07196ee41a0e562fa8a8cb7a01112ec5.1601565471.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/stackdepot.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

--- a/lib/stackdepot.c~lib-stackdepotc-use-flex_array_size-helper-in-memcpy
+++ a/lib/stackdepot.c
@@ -135,7 +135,7 @@  static struct stack_record *depot_alloc_
 	stack->handle.slabindex = depot_index;
 	stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN;
 	stack->handle.valid = 1;
-	memcpy(stack->entries, entries, size * sizeof(unsigned long));
+	memcpy(stack->entries, entries, flex_array_size(stack, entries, size));
 	depot_offset += required_size;
 
 	return stack;