linux-kernel - Re: [PATCH] f2fs: fix to adjust appropirate defragment pg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <fa4686b5-5197-4130-bfa7-215f15bafe35@kernel.org>
Date: Sat, 23 Mar 2024 11:02:04 +0800
From: Chao Yu <chao@...nel.org>
To: Zhiguo Niu <zhiguo.niu@...soc.com>, jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
 niuzhiguo84@...il.com, ke.wang@...soc.com, hongyu.jin@...soc.com
Subject: Re: [PATCH] f2fs: fix to adjust appropirate defragment pg_end

On 2024/3/22 14:03, Zhiguo Niu wrote:
> A length that exceeds the real size of the inode may be
> specified from user, although these out-of-range areas
> are not mapped, but they still need to be check in
> while loop, which is unnecessary.
> 
> Signed-off-by: Zhiguo Niu <zhiguo.niu@...soc.com>
> ---
>   fs/f2fs/file.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 128e53d..0e7eac6 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -2609,7 +2609,9 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi,
>   	int err;
>   
>   	pg_start = range->start >> PAGE_SHIFT;
> -	pg_end = (range->start + range->len) >> PAGE_SHIFT;
> +	pg_end = min_t(pgoff_t,
> +			(range->start + range->len) >> PAGE_SHIFT,
> +			DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE));

I guess we may check i_size w/ inode lock, it can avoid racing w/ append write
or truncate.

Thanks,

>   
>   	f2fs_balance_fs(sbi, true);
>