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author | Daniel Borkmann <daniel@iogearbox.net> | 2021-05-11 22:35:17 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-16 12:51:45 +0100 |
commit | 07e7f7cc619d15645e45d04b1c99550c6d292e9c (patch) | |
tree | d01382c9e0b3555bdd573be9e6292f55af1d551f /init | |
parent | cf9de6a36b01c25e0c03f92fc09af060ed813304 (diff) | |
download | linux-stable-07e7f7cc619d15645e45d04b1c99550c6d292e9c.tar.gz linux-stable-07e7f7cc619d15645e45d04b1c99550c6d292e9c.tar.bz2 linux-stable-07e7f7cc619d15645e45d04b1c99550c6d292e9c.zip |
bpf: Add kconfig knob for disabling unpriv bpf by default
commit 08389d888287c3823f80b0216766b71e17f0aba5 upstream.
Add a kconfig knob which allows for unprivileged bpf to be disabled by default.
If set, the knob sets /proc/sys/kernel/unprivileged_bpf_disabled to value of 2.
This still allows a transition of 2 -> {0,1} through an admin. Similarly,
this also still keeps 1 -> {1} behavior intact, so that once set to permanently
disabled, it cannot be undone aside from a reboot.
We've also added extra2 with max of 2 for the procfs handler, so that an admin
still has a chance to toggle between 0 <-> 2.
Either way, as an additional alternative, applications can make use of CAP_BPF
that we added a while ago.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net
[fllinden@amazon.com: backported to 4.19]
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'init')
-rw-r--r-- | init/Kconfig | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig index b56a125b5a76..0fe4f60c974d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1474,6 +1474,16 @@ config BPF_JIT_ALWAYS_ON Enables BPF JIT and removes BPF interpreter to avoid speculative execution of BPF instructions by the interpreter +config BPF_UNPRIV_DEFAULT_OFF + bool "Disable unprivileged BPF by default" + depends on BPF_SYSCALL + help + Disables unprivileged BPF by default by setting the corresponding + /proc/sys/kernel/unprivileged_bpf_disabled knob to 2. An admin can + still reenable it by setting it to 0 later on, or permanently + disable it by setting it to 1 (from which no other transition to + 0 is possible anymore). + config USERFAULTFD bool "Enable userfaultfd() system call" select ANON_INODES |