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openwrt/target/linux/generic/backport-6.6/611-03-v6.11-udp-Fall-back-to-software-USO-if-IPv6-extension-head.patch
John Audia 93cca95434 kernel: bump 6.6 to 6.6.48
Changelog: https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.48

Removed upstreamed:
	generic/backport-6.6/752-04-v6.6-net-ethernet-mtk_wed-check-update_wo_rx_stats-in-mtk.patch[1]
	generic/pending-6.6/601-udp-fix-receiving-fraglist-GSO_packets.patch[2]
	mediatek/patches-6.6/951-net-ethernet-mtk_wed-fix-use-after-free-panic-in-mtk.patch[3]
	rockchip/patches-6.6/302-mmc-allow-probe-to-defer-if-clock-is-not-ready.patch[4]

Manually rebased:
	bcm27xx/patches-6.6/950-0058-Revert-Bluetooth-Always-request-for-user-confirmatio.patch

All other patches automatically rebased.

1. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.48&id=7ede6ef04c9ffc466844a297d3d68bea8a06093d
2. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.48&id=cfa692e7e71b22d35174a796d10b9111bafa0686
3. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.48&id=326a89321f9d5fe399fe6f9ff7c0fc766582a6a0
4. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.48&id=7bbf8f8b8861dd2a6215f1aded425c66e6c376a0

Build system: x86/64
Build-tested: x86/64/AMD Cezanne, flogic/xiaomi_redmi-router-ax6000-ubootmod, ramips/tplink_archer-a6-v3
Run-tested: x86/64/AMD Cezanne, flogic/xiaomi_redmi-router-ax6000-ubootmod, ramips/tplink_archer-a6-v3

Signed-off-by: John Audia <therealgraysky@proton.me>
Link: https://github.com/openwrt/openwrt/pull/16282
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2024-08-31 20:08:13 +02:00

87 lines
3.9 KiB
Diff

From: Jakub Sitnicki <jakub@cloudflare.com>
Date: Thu, 8 Aug 2024 11:56:22 +0200
Subject: [PATCH] udp: Fall back to software USO if IPv6 extension headers are
present
In commit 10154dbded6d ("udp: Allow GSO transmit from devices with no
checksum offload") we have intentionally allowed UDP GSO packets marked
CHECKSUM_NONE to pass to the GSO stack, so that they can be segmented and
checksummed by a software fallback when the egress device lacks these
features.
What was not taken into consideration is that a CHECKSUM_NONE skb can be
handed over to the GSO stack also when the egress device advertises the
tx-udp-segmentation / NETIF_F_GSO_UDP_L4 feature.
This will happen when there are IPv6 extension headers present, which we
check for in __ip6_append_data(). Syzbot has discovered this scenario,
producing a warning as below:
ip6tnl0: caps=(0x00000006401d7869, 0x00000006401d7869)
WARNING: CPU: 0 PID: 5112 at net/core/dev.c:3293 skb_warn_bad_offload+0x166/0x1a0 net/core/dev.c:3291
Modules linked in:
CPU: 0 PID: 5112 Comm: syz-executor391 Not tainted 6.10.0-rc7-syzkaller-01603-g80ab5445da62 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:skb_warn_bad_offload+0x166/0x1a0 net/core/dev.c:3291
[...]
Call Trace:
<TASK>
__skb_gso_segment+0x3be/0x4c0 net/core/gso.c:127
skb_gso_segment include/net/gso.h:83 [inline]
validate_xmit_skb+0x585/0x1120 net/core/dev.c:3661
__dev_queue_xmit+0x17a4/0x3e90 net/core/dev.c:4415
neigh_output include/net/neighbour.h:542 [inline]
ip6_finish_output2+0xffa/0x1680 net/ipv6/ip6_output.c:137
ip6_finish_output+0x41e/0x810 net/ipv6/ip6_output.c:222
ip6_send_skb+0x112/0x230 net/ipv6/ip6_output.c:1958
udp_v6_send_skb+0xbf5/0x1870 net/ipv6/udp.c:1292
udpv6_sendmsg+0x23b3/0x3270 net/ipv6/udp.c:1588
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xef/0x270 net/socket.c:745
____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
___sys_sendmsg net/socket.c:2639 [inline]
__sys_sendmmsg+0x3b2/0x740 net/socket.c:2725
__do_sys_sendmmsg net/socket.c:2754 [inline]
__se_sys_sendmmsg net/socket.c:2751 [inline]
__x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2751
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[...]
</TASK>
We are hitting the bad offload warning because when an egress device is
capable of handling segmentation offload requested by
skb_shinfo(skb)->gso_type, the chain of gso_segment callbacks won't produce
any segment skbs and return NULL. See the skb_gso_ok() branch in
{__udp,tcp,sctp}_gso_segment helpers.
To fix it, force a fallback to software USO when processing a packet with
IPv6 extension headers, since we don't know if these can checksummed by
all devices which offer USO.
Fixes: 10154dbded6d ("udp: Allow GSO transmit from devices with no checksum offload")
Reported-by: syzbot+e15b7e15b8a751a91d9a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000e1609a061d5330ce@google.com/
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://patch.msgid.link/20240808-udp-gso-egress-from-tunnel-v4-2-f5c5b4149ab9@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -283,6 +283,12 @@ struct sk_buff *__udp_gso_segment(struct
!(skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST)))
return ERR_PTR(-EINVAL);
+ /* We don't know if egress device can segment and checksum the packet
+ * when IPv6 extension headers are present. Fall back to software GSO.
+ */
+ if (gso_skb->ip_summed != CHECKSUM_PARTIAL)
+ features &= ~(NETIF_F_GSO_UDP_L4 | NETIF_F_CSUM_MASK);
+
if (skb_gso_ok(gso_skb, features | NETIF_F_GSO_ROBUST)) {
/* Packet is from an untrusted source, reset gso_segs. */
skb_shinfo(gso_skb)->gso_segs = DIV_ROUND_UP(gso_skb->len - sizeof(*uh),