Messages in this thread | | | Subject | Re: NFSv3 directory traversal causes lockup in 4.9.214 | From | Bartos-Elekes Zsolt <> | Date | Sun, 22 Mar 2020 08:03:12 +0100 |
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Hi!
> I think I found a bug in 4.9.214: a simple directory traversal of a NFSv3-mounted filesystem causes system lockup after > a few seconds - everything attempting NFS and local disk access is blocked. The machine is still alive (responding to > pings and on the console), but I can't start any new programs. > > > 4.9.213 is OK, 4.9.214 is not. > > If we revert commit 67a56e9743171bdacddbdc05a58735aa024bb474 (commit 4b310319c6a8ce708f1033d57145e2aa027a883c upstream), > the problem goes away. > > > How to trigger the problem: > > mount nfs-server.example.com:/ /mnt/net -o vers=3,ro > find /mnt/net > > > I have observed this only on two older machines running in i386 mode (my home server, an Intel D2500HN, and a test > machine, a Lenovo ThinkCentre A57 (Product ID: 9851-7AG)), but could not trigger the bug on a Pentium III machine (all > three running the very same kernel).
I reply to myself: commit dbfc9e9878561da92cdcda41f321137c16966587 ("NFS: Remove superfluous kmap in nfs_readdir_xdr_to_array") in 4.9.217 fixes it.
-- Best regards, Zsolt
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