Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2021-01-29

1) Fix two copy_{from,to}_user() warn_on_once splats for BPF cgroup getsockopt
   infra when user space is trying to race against optlen, from Loris Reiff.

2) Fix a missing fput() in BPF inode storage map update helper, from Pan Bian.

3) Fix a build error on unresolved symbols on disabled networking / keys LSM
   hooks, from Mikko Ylinen.

4) Fix preload BPF prog build when the output directory from make points to a
   relative path, from Quentin Monnet.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, preload: Fix build when $(O) points to a relative path
  bpf: Drop disabled LSM hooks from the sleepable set
  bpf, inode_storage: Put file handler if no storage was found
  bpf, cgroup: Fix problematic bounds check
  bpf, cgroup: Fix optlen WARN_ON_ONCE toctou
====================

Link: https://lore.kernel.org/r/20210129001556.6648-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 96555a8a2c54..6aa9e10c6335 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1442,6 +1442,11 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 			goto out;
 		}
 
+		if (ctx.optlen < 0) {
+			ret = -EFAULT;
+			goto out;
+		}
+
 		if (copy_from_user(ctx.optval, optval,
 				   min(ctx.optlen, max_optlen)) != 0) {
 			ret = -EFAULT;
@@ -1459,7 +1464,7 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 		goto out;
 	}
 
-	if (ctx.optlen > max_optlen) {
+	if (ctx.optlen > max_optlen || ctx.optlen < 0) {
 		ret = -EFAULT;
 		goto out;
 	}