From: Eric Biggers <ebiggers@kernel.org>
To: viro@zeniv.linux.org.uk
Cc: dhowells@redhat.com, gregkh@linuxfoundation.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, miklos@szeredi.hu,
tglx@linutronix.de, Yin Fengwei <nh26223.lmm@gmail.com>,
kstewart@linuxfoundation.org
Subject: Re: [PATCH v2] fs: fs_parser: avoid NULL param->string to kstrtouint
Date: Thu, 15 Aug 2019 19:46:54 -0700 [thread overview]
Message-ID: <20190816024654.GA12185@sol.localdomain> (raw)
In-Reply-To: <20190719232949.27978-1-nh26223.lmm@gmail.com>
On Sat, Jul 20, 2019 at 07:29:49AM +0800, Yin Fengwei wrote:
> syzbot reported general protection fault in kstrtouint:
> https://lkml.org/lkml/2019/7/18/328
>
> From the log, if the mount option is something like:
> fd,XXXXXXXXXXXXXXXXXXXX
>
> The default parameter (which has NULL param->string) will be
> passed to vfs_parse_fs_param. Finally, this NULL param->string
> is passed to kstrtouint and trigger NULL pointer access.
>
> Reported-by: syzbot+398343b7c1b1b989228d@syzkaller.appspotmail.com
> Fixes: 71cbb7570a9a ("vfs: Move the subtype parameter into fuse")
>
> Signed-off-by: Yin Fengwei <nh26223.lmm@gmail.com>
> ---
> ChangeLog:
> v1 -> v2:
> - Fix typo in v1
> - Remove braces {} from single statement blocks
>
> fs/fs_parser.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/fs_parser.c b/fs/fs_parser.c
> index 83b66c9e9a24..7498a44f18c0 100644
> --- a/fs/fs_parser.c
> +++ b/fs/fs_parser.c
> @@ -206,6 +206,9 @@ int fs_parse(struct fs_context *fc,
> case fs_param_is_fd: {
> switch (param->type) {
> case fs_value_is_string:
> + if (!result->has_value)
> + goto bad_value;
> +
> ret = kstrtouint(param->string, 0, &result->uint_32);
> break;
> case fs_value_is_file:
> --
> 2.17.1
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Al, can you please apply this patch?
- Eric
next prev parent reply other threads:[~2019-08-16 2:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 23:29 [PATCH v2] fs: fs_parser: avoid NULL param->string to kstrtouint Yin Fengwei
2019-08-16 2:46 ` Eric Biggers [this message]
2019-08-22 4:22 ` Eric Biggers
2019-08-22 5:33 ` Al Viro
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