From: Loris Reiff <[email protected]>

[ 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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Reviewed-by: Stanislav Fomichev <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
 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 6ec8f02f463b6..6aa9e10c6335a 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1464,7 +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;
        }
-- 
2.27.0



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