bpf: skip unnecessary capability check
authorChenbo Feng <fengc@google.com>
Tue, 20 Mar 2018 00:57:27 +0000 (17:57 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 28 Mar 2018 16:39:26 +0000 (18:39 +0200)
commit3eb88807b26daef1342d733d75956ad50d72b9d6
tree269be7dbd86b7ef0e7a997d77c928a701fb01ce1
parent733a4e1af803b1094b26040fc50e5c821fa2f28f
bpf: skip unnecessary capability check

commit 0fa4fe85f4724fff89b09741c437cbee9cf8b008 upstream.

The current check statement in BPF syscall will do a capability check
for CAP_SYS_ADMIN before checking sysctl_unprivileged_bpf_disabled. This
code path will trigger unnecessary security hooks on capability checking
and cause false alarms on unprivileged process trying to get CAP_SYS_ADMIN
access. This can be resolved by simply switch the order of the statement
and CAP_SYS_ADMIN is not required anyway if unprivileged bpf syscall is
allowed.

Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/bpf/syscall.c