From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH] malloc: Switch global_max_fast to uint8_t
Date: Wed, 12 Oct 2022 16:02:11 +0200 [thread overview]
Message-ID: <87bkqhywbg.fsf@oldenburg.str.redhat.com> (raw)
MAX_FAST_SIZE is 160 at most, so a uint8_t is sufficient. This makes
it harder to use memory corruption, by overwriting global_max_fast
with a large value, to fundamentally alter malloc behavior.
Tested i686-linux-gnu and x86_64-linux-gnu.
---
malloc/malloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 953183e956..2a61c8b5ee 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1757,7 +1757,7 @@ typedef struct malloc_chunk *mfastbinptr;
#define set_contiguous(M) ((M)->flags &= ~NONCONTIGUOUS_BIT)
/* Maximum size of memory handled in fastbins. */
-static INTERNAL_SIZE_T global_max_fast;
+static uint8_t global_max_fast;
/*
Set value of max_fast.
base-commit: 264db94040c463d9bc356101595d89335586875e
next reply other threads:[~2022-10-12 14:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-12 14:02 Florian Weimer [this message]
2022-10-12 17:07 ` DJ Delorie
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