From: Qun-Wei Lin <qun-wei.lin@mediatek.com>
To: Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
Roman Gushchin <roman.gushchin@linux.dev>,
Hyeonggon Yoo <42.hyeyoo@gmail.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
Danilo Krummrich <dakr@kernel.org>
Cc: <catalin.marinas@arm.com>, <surenb@google.com>,
<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>, <bpf@vger.kernel.org>,
Casper Li <casper.li@mediatek.com>,
Chinwen Chang <chinwen.chang@mediatek.com>,
Andrew Yang <andrew.yang@mediatek.com>,
John Hsu <john.hsu@mediatek.com>, <wsd_upstream@mediatek.com>,
Qun-Wei Lin <qun-wei.lin@mediatek.com>
Subject: [PATCH] mm: krealloc: Fix MTE false alarm in __do_krealloc
Date: Fri, 25 Oct 2024 16:58:11 +0800 [thread overview]
Message-ID: <20241025085811.31310-1-qun-wei.lin@mediatek.com> (raw)
This patch addresses an issue introduced by commit 1a83a716ec233 ("mm:
krealloc: consider spare memory for __GFP_ZERO") which causes MTE
(Memory Tagging Extension) to falsely report a slab-out-of-bounds error.
The problem occurs when zeroing out spare memory in __do_krealloc. The
original code only considered software-based KASAN and did not account
for MTE. It does not reset the KASAN tag before calling memset, leading
to a mismatch between the pointer tag and the memory tag, resulting
in a false positive.
Example of the error:
==================================================================
swapper/0: BUG: KASAN: slab-out-of-bounds in __memset+0x84/0x188
swapper/0: Write at addr f4ffff8005f0fdf0 by task swapper/0/1
swapper/0: Pointer tag: [f4], memory tag: [fe]
swapper/0:
swapper/0: CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.
swapper/0: Hardware name: MT6991(ENG) (DT)
swapper/0: Call trace:
swapper/0: dump_backtrace+0xfc/0x17c
swapper/0: show_stack+0x18/0x28
swapper/0: dump_stack_lvl+0x40/0xa0
swapper/0: print_report+0x1b8/0x71c
swapper/0: kasan_report+0xec/0x14c
swapper/0: __do_kernel_fault+0x60/0x29c
swapper/0: do_bad_area+0x30/0xdc
swapper/0: do_tag_check_fault+0x20/0x34
swapper/0: do_mem_abort+0x58/0x104
swapper/0: el1_abort+0x3c/0x5c
swapper/0: el1h_64_sync_handler+0x80/0xcc
swapper/0: el1h_64_sync+0x68/0x6c
swapper/0: __memset+0x84/0x188
swapper/0: btf_populate_kfunc_set+0x280/0x3d8
swapper/0: __register_btf_kfunc_id_set+0x43c/0x468
swapper/0: register_btf_kfunc_id_set+0x48/0x60
swapper/0: register_nf_nat_bpf+0x1c/0x40
swapper/0: nf_nat_init+0xc0/0x128
swapper/0: do_one_initcall+0x184/0x464
swapper/0: do_initcall_level+0xdc/0x1b0
swapper/0: do_initcalls+0x70/0xc0
swapper/0: do_basic_setup+0x1c/0x28
swapper/0: kernel_init_freeable+0x144/0x1b8
swapper/0: kernel_init+0x20/0x1a8
swapper/0: ret_from_fork+0x10/0x20
==================================================================
Fixes: 1a83a716ec233 ("mm: krealloc: consider spare memory for
__GFP_ZERO")
Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
---
mm/slab_common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 3d26c257ed8b..3445f4500b54 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1209,7 +1209,7 @@ __do_krealloc(const void *p, size_t new_size, gfp_t flags)
/* Zero out spare memory. */
if (want_init_on_alloc(flags)) {
kasan_disable_current();
- memset((void *)p + new_size, 0, ks - new_size);
+ memset(kasan_reset_tag((void *)p + new_size), 0, ks - new_size);
kasan_enable_current();
}
--
2.45.2
next reply other threads:[~2024-10-25 8:58 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-25 8:58 Qun-Wei Lin [this message]
2024-10-25 9:54 ` Vlastimil Babka
2024-10-26 5:46 ` David Rientjes
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20241025085811.31310-1-qun-wei.lin@mediatek.com \
--to=qun-wei.lin@mediatek.com \
--cc=42.hyeyoo@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andrew.yang@mediatek.com \
--cc=angelogioacchino.delregno@collabora.com \
--cc=bpf@vger.kernel.org \
--cc=casper.li@mediatek.com \
--cc=catalin.marinas@arm.com \
--cc=chinwen.chang@mediatek.com \
--cc=cl@linux.com \
--cc=dakr@kernel.org \
--cc=iamjoonsoo.kim@lge.com \
--cc=john.hsu@mediatek.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=linux-mm@kvack.org \
--cc=matthias.bgg@gmail.com \
--cc=penberg@kernel.org \
--cc=rientjes@google.com \
--cc=roman.gushchin@linux.dev \
--cc=surenb@google.com \
--cc=vbabka@suse.cz \
--cc=wsd_upstream@mediatek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox