lkml.org 
[lkml]   [2023]   [Jan]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v2 1/2] f2fs: fix to avoid potential memory corruption in __update_iostat_latency()
On 2023/1/16 21:02, Yangtao Li wrote:
> Add iotype sanity check to avoid potential memory corruption.
> This is to fix the compile error below:
>
> fs/f2fs/iostat.c:231 __update_iostat_latency() error: buffer overflow
> 'io_lat->peak_lat[type]' 3 <= 3
>
> vim +228 fs/f2fs/iostat.c
>
> 211 static inline void __update_iostat_latency(struct bio_iostat_ctx
> *iostat_ctx,
> 212 enum iostat_lat_type type)
> 213 {
> 214 unsigned long ts_diff;
> 215 unsigned int page_type = iostat_ctx->type;
> 216 struct f2fs_sb_info *sbi = iostat_ctx->sbi;
> 217 struct iostat_lat_info *io_lat = sbi->iostat_io_lat;
> 218 unsigned long flags;
> 219
> 220 if (!sbi->iostat_enable)
> 221 return;
> 222
> 223 ts_diff = jiffies - iostat_ctx->submit_ts;
> 224 if (page_type >= META_FLUSH)
> ^^^^^^^^^^
>
> 225 page_type = META;
> 226
> 227 spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
> @228 io_lat->sum_lat[type][page_type] += ts_diff;
> ^^^^^^^^^
> Mixup between META_FLUSH and NR_PAGE_TYPE leads to memory corruption.
>
> Fixes: a4b6817625e7 ("f2fs: introduce periodic iostat io latency traces")
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Signed-off-by: Yangtao Li <frank.li@vivo.com>
> ---
> fs/f2fs/iostat.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/iostat.c b/fs/f2fs/iostat.c
> index ed8176939aa5..e9a3df7ce4d9 100644
> --- a/fs/f2fs/iostat.c
> +++ b/fs/f2fs/iostat.c
> @@ -223,7 +223,7 @@ static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
> return;
>
> ts_diff = jiffies - iostat_ctx->submit_ts;
> - if (iotype >= META_FLUSH)
> + if (iotype == META_FLUSH)

Maybe it's betterr to merge these two check condition as below?

if (iotype >= NR_PAGE_TYPE) {
f2fs_bug_on(sbi, iotype != META_FLUSH);
iotype = META;
}

For CHECK_FS is off case, I guess it's fine to not return and just print
warning message for notice.

Thanks,

> iotype = META;
>
> if (rw == 0) {
> @@ -235,6 +235,11 @@ static inline void __update_iostat_latency(struct bio_iostat_ctx *iostat_ctx,
> idx = WRITE_ASYNC_IO;
> }
>
> + if (iotype >= NR_PAGE_TYPE) {
> + f2fs_bug_on(sbi, 1);
> + return;
> + }
> +
> spin_lock_irqsave(&sbi->iostat_lat_lock, flags);
> io_lat->sum_lat[idx][iotype] += ts_diff;
> io_lat->bio_cnt[idx][iotype]++;

\
 
 \ /
  Last update: 2023-03-26 23:42    [W:0.067 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site