On Thu, Jun 23, 2022 at 09:49:56AM +0000, cgel.zte@xxxxxxxxx wrote: > From: xu xin <xu.xin16@xxxxxxxxxx> > > As the bug description at > https://lore.kernel.org/lkml/20220623033635.973929-1-xu.xin16@xxxxxxxxxx/ > attckers can use this bug to crash the system. > > So to avoid panic, remove the BUG_ON, and use ntfs_warning to output a > warning to the syslog and return instead until someone really solve > the problem. > > Cc: stable@xxxxxxxxxxxxxxx > Reported-by: Zeal Robot <zealci@xxxxxxxxxx> > Reported-by: syzbot+6a5a7672f663cce8b156@xxxxxxxxxxxxxxxxxxxxxxxxx > Reviewed-by: Songyi Zhang <zhang.songyi@xxxxxxxxxx> > Reviewed-by: Yang Yang <yang.yang29@xxxxxxxxxx> > Reviewed-by: Jiang Xuexin<jiang.xuexin@xxxxxxxxxx> > Reviewed-by: Zhang wenya<zhang.wenya1@xxxxxxxxxx> > Signed-off-by: xu xin <xu.xin16@xxxxxxxxxx> > --- > > Change for v2: > - Use ntfs_warning instead of WARN(). > - Add the tag Cc: stable@xxxxxxxxxxxxxxx. > --- > fs/ntfs/aops.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c > index 5f4fb6ca6f2e..84d68efb4ace 100644 > --- a/fs/ntfs/aops.c > +++ b/fs/ntfs/aops.c > @@ -183,7 +183,12 @@ static int ntfs_read_block(struct page *page) > vol = ni->vol; > > /* $MFT/$DATA must have its complete runlist in memory at all times. */ > - BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni)); > + if (unlikely(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni))) { > + ntfs_warning(vi->i_sb, "Error because ni->runlist.rl, ni->mft_no, " > + "and NInoAttr(ni) is null."); > + unlock_page(page); > + return -EINVAL; > + } A better warning message that doesn't rely on implementation details (struct field and macro names) would be "Runlist of $MFT/$DATA is not cached". Also, why does this situation happen in the first place? Is there a way to prevent this situation in the first place? - Eric
