From: Al Viro <viro@zeniv.linux.org.uk>
To: Lizhi Xu <lizhi.xu@windriver.com>
Cc: syzbot+24ac24ff58dc5b0d26b9@syzkaller.appspotmail.com,
brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, phillip@squashfs.org.uk,
squashfs-devel@lists.sourceforge.net,
syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap
Date: Thu, 1 Aug 2024 03:58:42 +0100 [thread overview]
Message-ID: <20240801025842.GM5334@ZenIV> (raw)
In-Reply-To: <20240801022739.1199700-1-lizhi.xu@windriver.com>
On Thu, Aug 01, 2024 at 10:27:39AM +0800, Lizhi Xu wrote:
> syzbot report KMSAN: uninit-value in pick_link, this is because the
> corresponding folio was not found from the mapping, and the memory was
> not initialized when allocating a new folio for the filemap.
>
> To avoid the occurrence of kmsan report uninit-value, initialize the
> newly allocated folio memory to 0.
NAK.
You are papering over the real bug here.
That page either
* has been returned by find_get_page(), cached, uptodate and
with uninitialized contents or
* has been returned by successful read_mapping_page() - and
left with uninitialized contents or
* had inode->i_size in excess of initialized contents.
I'd suggest bisecting that.
next prev parent reply other threads:[~2024-08-01 2:58 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-07-31 8:12 [syzbot] [squashfs?] KMSAN: uninit-value in pick_link syzbot
2024-08-01 2:27 ` [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap Lizhi Xu
2024-08-01 2:58 ` Al Viro [this message]
2024-08-01 5:28 ` Lizhi Xu
2024-08-01 7:10 ` Al Viro
2024-08-01 7:24 ` Al Viro
2024-08-01 8:12 ` Lizhi Xu
2024-08-01 9:13 ` Lizhi Xu
2024-08-01 12:42 ` Al Viro
2024-08-01 15:17 ` [PATCH V2] squashfs: Add length check in squashfs_symlink_read_folio Lizhi Xu
2024-08-01 15:30 ` Jan Kara
2024-08-02 1:39 ` Lizhi Xu
2024-08-02 1:50 ` [PATCH V3] squashfs: Add i_size check in squash_read_inode Lizhi Xu
2024-08-02 3:01 ` [PATCH V4] " Lizhi Xu
2024-08-02 9:33 ` Jan Kara
2024-08-02 11:16 ` [PATCH V5] " Lizhi Xu
2024-08-02 13:52 ` Al Viro
2024-08-02 14:44 ` [PATCH] filemap: Init the newly allocated folio memory to 0 for the filemap Lizhi Xu
2024-08-02 15:03 ` Al Viro
2024-08-03 4:07 ` [PATCH V6] squashfs: Add symlink size check in squash_read_inode Lizhi Xu
2024-08-03 7:43 ` [PATCH V7] " Lizhi Xu
2024-08-04 21:16 ` Phillip Lougher
2024-08-04 21:20 ` Al Viro
2024-08-04 22:31 ` Phillip Lougher
2024-08-05 7:03 ` Christian Brauner
2024-08-05 1:02 ` Lizhi Xu
2024-08-05 1:40 ` Al Viro
2024-08-06 2:56 ` Lizhi Xu
2024-08-06 4:59 ` Al Viro
2024-08-06 6:19 ` Lizhi Xu
2024-08-06 6:58 ` Al Viro
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