Closed
Description
System information
| Type | Version/Name |
|---|---|
| Distribution Name | Debian |
| Distribution Version | sid, mostly up-to-date as of Sun 11 Apr 00:35:52 CEST 2021 |
| Linux Kernel | Linux szarotka 5.10.0-5-amd64 #1 SMP Debian 5.10.24-1 (2021-03-19) x86_64 GNU/Linux |
| Architecture | x32 |
| ZFS Version | 2.0.3-6 |
Describe the problem you're observing
All reads on /proc/sys/kernel/spl/hostid return -EFAULT, tracked this back to this mainline commit with a v5.7-rc1-4-g32927393dc1c describe:
commit 32927393dc1ccd60fb2bdc05b9e8e88753761469
Author: Christoph Hellwig <[email protected]>
Date: Fri Apr 24 08:43:38 2020 +0200
sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Andrey Ignatov <[email protected]>
Signed-off-by: Al Viro <[email protected]>
This makes the access_ok() in copy_to_user() in proc_copyout_string() in proc_dohostid() fail, since ubuffer is kernel memory now – proc_dostring() just does a memcpy.
This is the only affected path, since all others delegate to kernel's proc_do*() functions.