From: Al Viro <viro@zeniv.linux.org.uk>
To: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Cc: namjae.jeon@samsung.com, sj1557.seo@samsung.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller <syzkaller@googlegroups.com>
Subject: Re: memory leak in exfat_parse_param
Date: Tue, 2 Jun 2020 17:28:08 +0100 [thread overview]
Message-ID: <20200602162808.GK23230@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAFcO6XPVo-u0CkBxy0Ox+FPfqgPUwmo0pnVYrLCP6EM05Sd6-A@mail.gmail.com>
On Tue, Jun 02, 2020 at 01:03:05PM +0800, butt3rflyh4ck wrote:
> I report a bug (in linux-5.7.0-rc7) found by syzkaller.
>
> kernel config: https://github.com/butterflyhack/syzkaller-fuzz/blob/master/config-v5.7.0-rc7
>
> and can reproduce.
>
> A param->string held by exfat_mount_options.
Humm...
First of all, exfat_free() ought to call exfat_free_upcase_table().
What's more, WTF bother with that kstrdup(), anyway? Just steal the string
and be done with that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 0565d5539d57..01cd7ed1614d 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -259,9 +259,8 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
break;
case Opt_charset:
exfat_free_iocharset(sbi);
- opts->iocharset = kstrdup(param->string, GFP_KERNEL);
- if (!opts->iocharset)
- return -ENOMEM;
+ opts->iocharset = param->string;
+ param->string = NULL;
break;
case Opt_errors:
opts->errors = result.uint_32;
@@ -611,7 +610,10 @@ static int exfat_get_tree(struct fs_context *fc)
static void exfat_free(struct fs_context *fc)
{
- kfree(fc->s_fs_info);
+ struct exfat_sb_info *sbi = fc->s_fs_info;
+
+ exfat_free_iocharset(sbi);
+ kfree(sbi);
}
static const struct fs_context_operations exfat_context_ops = {
next prev parent reply other threads:[~2020-06-02 16:28 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 5:03 memory leak in exfat_parse_param butt3rflyh4ck
2020-06-02 16:28 ` Al Viro [this message]
2020-06-03 1:32 ` Namjae Jeon
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