[merged mm-hotfixes-stable] mm-fix-vreallocs-kasan-poisoning-logic.patch removed from -mm tree

[merged mm-hotfixes-stable] mm-fix-vreallocs-kasan-poisoning-logic.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: fix vrealloc()'s KASAN poisoning logic
has been removed from the -mm tree.  Its filename was
     mm-fix-vreallocs-kasan-poisoning-logic.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Andrii Nakryiko <andrii@kernel.org>
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.

This results in a KASAN splat recorded at [1].  A KASAN mis-reporting
issue where there is none.

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@kernel.org
Link: https://lore.kernel.org/bpf/67450f9b.050a0220.21d33d.0004.GAE@google.com/ [1]
Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@kernel.org are