From: Loris Reiff loris.reiff@liblor.ch
[ Upstream commit f4a2da755a7e1f5d845c52aee71336cee289935a ]
Since ctx.optlen is signed, a larger value than max_value could be passed, as it is later on used as unsigned, which causes a WARN_ON_ONCE in the copy_to_user.
Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Signed-off-by: Loris Reiff loris.reiff@liblor.ch Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Stanislav Fomichev sdf@google.com Link: https://lore.kernel.org/bpf/20210122164232.61770-2-loris.reiff@liblor.ch Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 5b2413eb79db4..c2f0aa818b7af 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1131,7 +1131,7 @@ 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; }