Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Mon, 16 Jan 2023 21:25:27 +0800 | From | Chao Yu <> | Subject | Re: [PATCH v2 1/2] f2fs: fix to avoid potential memory corruption in __update_iostat_latency() |
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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]++;
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