BUG: unable to handle kernel paging request in z_erofs_decompress_queue

From: Tudor Ambarus
Date: Thu Dec 15 2022 - 07:58:19 EST


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,
ta

[1] https://syzkaller.appspot.com/bug?id=a9b56d324d0de9233ad80633826fac76836d792a