Messages in this thread | | | Date | Mon, 5 Aug 2019 17:42:15 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] Revert "f2fs: avoid out-of-range memory access" |
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On 08/02, Chao Yu wrote: > As Pavel Machek reported: > > "We normally use -EUCLEAN to signal filesystem corruption. Plus, it is > good idea to report it to the syslog and mark filesystem as "needing > fsck" if filesystem can do that." > > Still we need improve the original patch with: > - use unlikely keyword > - add message print > - return EUCLEAN > > However, after rethink this patch, I don't think we should add such > condition check here as below reasons: > - We have already checked the field in f2fs_sanity_check_ckpt(), > - If there is fs corrupt or security vulnerability, there is nothing > to guarantee the field is integrated after the check, unless we do > the check before each of its use, however no filesystem does that. > - We only have similar check for bitmap, which was added due to there > is bitmap corruption happened on f2fs' runtime in product. > - There are so many key fields in SB/CP/NAT did have such check > after f2fs_sanity_check_{sb,cp,..}. > > So I propose to revert this unneeded check.
IIRC, this came from security vulnerability report which can access out-of-boundary memory region. Could you write another patch to address the above issues?
> > This reverts commit 56f3ce675103e3fb9e631cfb4131fc768bc23e9a. > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > --- > fs/f2fs/segment.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 9693fa4c8971..2eff9c008ae0 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3492,11 +3492,6 @@ static int read_compacted_summaries(struct f2fs_sb_info *sbi) > seg_i = CURSEG_I(sbi, i); > segno = le32_to_cpu(ckpt->cur_data_segno[i]); > blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]); > - if (blk_off > ENTRIES_IN_SUM) { > - f2fs_bug_on(sbi, 1); > - f2fs_put_page(page, 1); > - return -EFAULT; > - } > seg_i->next_segno = segno; > reset_curseg(sbi, i, 0); > seg_i->alloc_type = ckpt->alloc_type[i]; > -- > 2.18.0.rc1
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