CVE-2021-47179 Information

Description

In the Linux kernel the following vulnerability has been resolved:

NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return()

Commit de144ff4234f changes _pnfs_return_layout() to call pnfs_mark_matching_lsegs_return() passing NULL as the struct pnfs_layout_range argument. Unfortunately pnfs_mark_matching_lsegs_return() doesn’t check if we have a value here before dereferencing it causing an oops.

I’m able to hit this crash consistently when running connectathon basic tests on NFS v4.1/v4.2 against Ontap.

Reference

https://git.kernel.org/stable/c/4e1ba532dbc1a0e19fc2458d74ab8d98680c4e42 https://git.kernel.org/stable/c/42637ca25c7d7b5a92804a679af5192e8c1a9f48 https://git.kernel.org/stable/c/39785761feadf261bc5101372b0b0bbaf6a94494 https://git.kernel.org/stable/c/aba3c7795f51717ae316f3566442dee7cc3eeccb https://git.kernel.org/stable/c/f9890652185b72b8de9ebeb4406037640b6e1b53 https://git.kernel.org/stable/c/b090d110e66636bca473fd8b98d5c97b555a965a