On 10/09, Chao Yu wrote: > On 2020/10/9 9:50, jaeg...@kernel.org wrote: > > On 10/09, Chao Yu wrote: > > > On 2020/10/8 5:53, jaeg...@kernel.org wrote: > > > > On 10/07, Eric Biggers wrote: > > > > > [moved linux-fsdevel to Bcc] > > > > > > > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote: > > > > > > Hello, > > > > > > > > > > > > syzbot found the following issue on: > > > > > > > > > > > > HEAD commit: a804ab08 Add linux-next specific files for 20201006 > > > > > > git tree: linux-next > > > > > > console output: > > > > > > https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000 > > > > > > kernel config: > > > > > > https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb > > > > > > dashboard link: > > > > > > https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13 > > > > > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > > > > > syz repro: > > > > > > https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000 > > > > > > C reproducer: > > > > > > https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000 > > > > > > > > > > > > The issue was bisected to: > > > > > > > > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4 > > > > > > Author: Jaegeuk Kim <jaeg...@kernel.org> > > > > > > Date: Fri Oct 2 21:17:35 2020 +0000 > > > > > > > > > > > > f2fs: f2fs_get_meta_page_nofail should not be failed > > > > > > > > > > > > > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't > > > > > terminate > > > > > if the requested page is beyond the end of the device. > > > > > > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic > > > > during > > > > the device reboot. Let me think how to avoid that before trying to get > > > > the > > > > wrong lba access. > > > > > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes > > > change, I think > > > we can just zeroing sum_page in error case, as we have already shutdown > > > f2fs via > > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all > > > updates to > > > filesystem data including summary pages. > > > > That sounds like one solution tho, I'm afraid of getting another panic by > > wrong zero'ed summary page. > > What case do you mean? maybe I missed some corner cases?
I sent v2 to fix syzbot issue, which fixes wrong use of f2fs_get_meta_page_nofail. > > Thanks, > > > > > > > > > Thoughts? > > > > > > Thanks, > > > > > > > > > > > > > > > > > - Eric > > > > > > > > > > > > _______________________________________________ > > > > Linux-f2fs-devel mailing list > > > > linux-f2fs-de...@lists.sourceforge.net > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > > > . > > > > > > . > >
