diff options
| author | Rongguang Wei <weirongguang@kylinos.cn> | 2026-08-07 15:09:14 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-08-10 16:37:08 -0700 |
| commit | fac7973f004de6dd51fb15a33e33ed37718e58bb (patch) | |
| tree | 3c31559b5b2ed91612b60588f2274393ad753022 | |
| parent | 34b270e7893f4a1e2257051e98fcb8cd8ef872c9 (diff) | |
tap: fix incorrect variable used for USO check in set_offload()
The USO features in set_offload() incorrectly uses feature_mask and
features argument.
The USO feature was written to the local features variable instead of
feature_mask. All other offload bits (TSO, TSO_ECN) are stored in
feature_mask which becomes tap->tap_features and is used by
tap_handle_frame() for GSO segmentation. Without NETIF_F_GSO_UDP_L4
in tap->tap_features, making USO on tap effectively non-functional.
Keeping the USO handling inside the TUN_F_CSUM block avoids enabling
GRO/LRO when userspace requests USO without CSUM.
This has not worked since the beginning, so
commit 399e0827642f ("driver/net/tun: Added features for USO.")
Signed-off-by: Rongguang Wei <weirongguang@kylinos.cn>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260807070914.112698-1-clementwei90@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/tap.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 5d2d34d24ce8..d4ca2fee538b 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -883,7 +883,7 @@ static int set_offload(struct tap_queue *q, unsigned long arg) /* TODO: for now USO4 and USO6 should work simultaneously */ if ((arg & (TUN_F_USO4 | TUN_F_USO6)) == (TUN_F_USO4 | TUN_F_USO6)) - features |= NETIF_F_GSO_UDP_L4; + feature_mask |= NETIF_F_GSO_UDP_L4; } /* tun/tap driver inverts the usage for TSO offloads, where @@ -894,8 +894,7 @@ static int set_offload(struct tap_queue *q, unsigned long arg) * When user space turns off TSO, we turn off GSO/LRO so that * user-space will not receive TSO frames. */ - if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6) || - (feature_mask & (TUN_F_USO4 | TUN_F_USO6)) == (TUN_F_USO4 | TUN_F_USO6)) + if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4)) features |= RX_OFFLOADS; else features &= ~RX_OFFLOADS; |