Messages in this thread Patch in this message | | | Subject | Re: [PATCH v2] f2fs: avoid out-of-range memory access | From | Chao Yu <> | Date | Wed, 3 Jul 2019 10:07:11 +0800 |
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Hi Ocean,
If filesystem is corrupted, it should fail mount due to below check in f2fs_sanity_check_ckpt(), so we are safe in read_compacted_summaries() to access entries[0,blk_off], right?
for (i = 0; i < NR_CURSEG_DATA_TYPE; i++) { if (le32_to_cpu(ckpt->cur_data_segno[i]) >= main_segs || le16_to_cpu(ckpt->cur_data_blkoff[i]) >= blocks_per_seg) return 1;
Thanks,
On 2019/7/2 16:05, Ocean Chen wrote: > blk_off might over 512 due to fs corrupt. > Use ENTRIES_IN_SUM to protect invalid memory access. > > v2: > - fix typo > Signed-off-by: Ocean Chen <oceanchen@google.com> > --- > fs/f2fs/segment.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 8dee063c833f..a5e8af0bd62e 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3403,6 +3403,8 @@ static int read_compacted_summaries(struct f2fs_sb_info *sbi) > > for (j = 0; j < blk_off; j++) { > struct f2fs_summary *s; > + if (j >= ENTRIES_IN_SUM) > + return -EFAULT; > s = (struct f2fs_summary *)(kaddr + offset); > seg_i->sum_blk->entries[j] = *s; > offset += SUMMARY_SIZE; >
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