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| author | Chenbo Feng <fengc@google.com> | 2018-03-19 17:57:27 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-28 18:24:50 +0200 |
| commit | b4e02202a0ba47d7ba546ae681f66ed68e69d459 (patch) | |
| tree | 2fd76d4e73d6a622b16302c784dc659a064e5426 | |
| parent | 3e1130970ec38bae0d4dd2a38678e563f092f7b3 (diff) | |
| download | linux-exynos-b4e02202a0ba47d7ba546ae681f66ed68e69d459.tar.gz linux-exynos-b4e02202a0ba47d7ba546ae681f66ed68e69d459.tar.bz2 linux-exynos-b4e02202a0ba47d7ba546ae681f66ed68e69d459.zip | |
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>
| -rw-r--r-- | kernel/bpf/syscall.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 25d074920a00..4e933219fec6 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1455,7 +1455,7 @@ 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; err = check_uarg_tail_zero(uattr, sizeof(attr), size); |