Messages in this thread | | | Date | Tue, 20 Dec 2022 17:42:21 +0200 | Subject | Re: BUG: unable to handle kernel paging request in z_erofs_decompress_queue | From | Tudor Ambarus <> |
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Hi, Gao,
On 15.12.2022 16:24, Gao Xiang wrote: > Hi Tudor, > > On Thu, Dec 15, 2022 at 02:58:10PM +0200, Tudor Ambarus wrote: >> Hi, Gao, Chao, Yue, Jeffle, all, >> >> Syzbot reported a bug at [1] that is reproducible in upstream kernel >> since >> commit 47e4937a4a7c ("erofs: move erofs out of staging") >> >> and up to (inclusively) >> commit 2bfab9c0edac ("erofs: record the longest decompressed size in this >> round") >> >> The first commit that makes this bug go away is: >> commit 267f2492c8f7 ("erofs: introduce multi-reference pclusters >> (fully-referenced)") >> Although, this commit looks like new support and not like an explicit >> bug fix. >> >> I'd like to fix the lts kernels. I'm happy to try any suggestions or do >> some tests. Please let me know if the bug rings a bell. > > Thanks for your report. I will try to seek time to look at this this > weekend. But just from your description, I guess that there could be > something wrong on several compressed extents pointing to the same > blocks (i.e. the same pcluster). But prior to commit 267f2492c8f7, such > image is always considered as corrupted images. > > Anyway, I will look into that and see if there could be alternative ways > to fix this rather than backport the whole multi-reference pcluster > feature. Yet I think no need to worry since such image is pretty > crafted and should be used as normal images.
I guess to backport the multi-reference pcluster feature is not an option for stable - just fixes are accepted. If you think it is worth fixing the problem without adding new support, I can dive into it. Let me know what you think.
Thanks, ta
> > Thanks, > Gao Xiang > >> >> Thanks, >> ta >> >> [1] >> https://syzkaller.appspot.com/bug?id=a9b56d324d0de9233ad80633826fac76836d792a
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