bpf: skip unnecessary capability check
authorChenbo Feng <[email protected]>
Tue, 20 Mar 2018 00:57:27 +0000 (17:57 -0700)
committerDaniel Borkmann <[email protected]>
Tue, 20 Mar 2018 22:50:39 +0000 (23:50 +0100)
commit0fa4fe85f4724fff89b09741c437cbee9cf8b008
tree38f02d936f9ef5b3e9fe9af90f8565c76d16e91a
parentf005afede992e265bb98534b86912bb669ccd0d2
bpf: skip unnecessary capability check

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 <[email protected]>
Acked-by: Lorenzo Colitti <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
kernel/bpf/syscall.c