Messages in this thread | | | Subject | Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail() | From | Chao Yu <> | Date | Fri, 9 Oct 2020 10:37:01 +0800 |
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On 2020/10/9 9:50, jaegeuk@kernel.org wrote: > On 10/09, Chao Yu wrote: >> On 2020/10/8 5:53, jaegeuk@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 <jaegeuk@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?
Thanks,
> >> >> Thoughts? >> >> Thanks, >> >>> >>>> >>>> - Eric >>> >>> >>> _______________________________________________ >>> Linux-f2fs-devel mailing list >>> Linux-f2fs-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel >>> . >>> > . >
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