From 3eb88807b26daef1342d733d75956ad50d72b9d6 Mon Sep 17 00:00:00 2001 From: Chenbo Feng Date: Mon, 19 Mar 2018 17:57:27 -0700 Subject: [PATCH] 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 Acked-by: Lorenzo Colitti Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 91a2d37..f8b4e3e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -801,7 +801,7 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz union bpf_attr attr = {}; int err; - if (!capable(CAP_SYS_ADMIN) && sysctl_unprivileged_bpf_disabled) + if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN)) return -EPERM; if (!access_ok(VERIFY_READ, uattr, 1)) -- 2.7.4