[PATCH net-next] tap: report IFF_DETACH_QUEUE in TUNGETIFF
From: Umang Pokhriyal <hidden>
Date: 2026-09-29 14:24:30
Also in:
lkml
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
tun sets IFF_DETACH_QUEUE in the flags returned by TUNGETIFF when the
queue is detached, since commit 3d407a80b62f ("tun: Report whether the
queue is attached or not"). tap_ioctl() returns only q->flags, so a
detached macvtap or ipvtap queue is reported as attached.
Cloud Hypervisor ran into this when checking queue state on macvtap.
Report the flag from q->enabled, as tun does.
Assisted-by: LLM
Signed-off-by: Umang Pokhriyal <redacted>
---
drivers/net/tap.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index ff67d99deb39e..cb8ffb0c4a315 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c@@ -950,6 +950,8 @@ static long tap_ioctl(struct file *file, unsigned int cmd, ret = 0; u = q->flags; + if (!q->enabled) + u |= IFF_DETACH_QUEUE; if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || put_user(u, &ifr->ifr_flags)) ret = -EFAULT;
base-commit: c66d93e68728cfb5f40b40d0f24129d7768faf43 -- 2.53.0