The patch titled
Subject: mm: fix vrealloc()'s KASAN poisoning logic
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-fix-vreallocs-kasan-poisoning-logic.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-vreallocs-kasan-poisoning-logic.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrii Nakryiko <andrii@xxxxxxxxxx>
Subject: mm: fix vrealloc()'s KASAN poisoning logic
Date: Mon, 25 Nov 2024 16:52:06 -0800
When vrealloc() reuses already allocated vmap_area, we need to re-annotate
poisoned and unpoisoned portions of underlying memory according to the new
size.
Note, hard-coding KASAN_VMALLOC_PROT_NORMAL might not be exactly correct,
but KASAN flag logic is pretty involved and spread out throughout
__vmalloc_node_range_noprof(), so I'm using the bare minimum flag here and
leaving the rest to mm people to refactor this logic and reuse it here.
Link: https://lkml.kernel.org/r/20241126005206.3457974-1-andrii@xxxxxxxxxx
Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/vmalloc.c~mm-fix-vreallocs-kasan-poisoning-logic
+++ a/mm/vmalloc.c
@@ -4093,7 +4093,8 @@ void *vrealloc_noprof(const void *p, siz
/* Zero out spare memory. */
if (want_init_on_alloc(flags))
memset((void *)p + size, 0, old_size - size);
-
+ kasan_poison_vmalloc(p + size, old_size - size);
+ kasan_unpoison_vmalloc(p, size, KASAN_VMALLOC_PROT_NORMAL);
return (void *)p;
}
_
Patches currently in -mm which might be from andrii@xxxxxxxxxx are
mm-fix-vreallocs-kasan-poisoning-logic.patch
