Jakob Unterwurzacher 26dc498a9f net: dsa: microchip: linearize skb for tail-tagging switches ... [ Upstream commit ba54bce747 ] The pointer arithmentic for accessing the tail tag only works for linear skbs. For nonlinear skbs, it reads uninitialized memory inside the skb headroom, essentially randomizing the tag. I have observed it gets set to 6 most of the time. Example where ksz9477_rcv thinks that the packet from port 1 comes from port 6 (which does not exist for the ksz9896 that's in use), dropping the packet. Debug prints added by me (not included in this patch): [ 256.645337] ksz9477_rcv:323 tag0=6 [ 256.645349] skb len=47 headroom=78 headlen=0 tailroom=0 mac=(64,14) mac_len=14 net=(78,0) trans=78 shinfo(txflags=0 nr_frags=1 gso(size=0 type=0 segs=0)) csum(0x0 start=0 offset=0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x00f8 pkttype=1 iif=3 priority=0x0 mark=0x0 alloc_cpu=0 vlan_all=0x0 encapsulation=0 inner(proto=0x0000, mac=0, net=0, trans=0) [ 256.645377] dev name=end1 feat=0x0002e10200114bb3 [ 256.645386] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645395] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645403] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645411] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 256.645420] skb headroom: 00000040: ff ff ff ff ff ff 00 1c 19 f2 e2 db 08 06 [ 256.645428] skb frag: 00000000: 00 01 08 00 06 04 00 01 00 1c 19 f2 e2 db 0a 02 [ 256.645436] skb frag: 00000010: 00 83 00 00 00 00 00 00 0a 02 a0 2f 00 00 00 00 [ 256.645444] skb frag: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 [ 256.645452] ksz_common_rcv:92 dsa_conduit_find_user returned NULL Call skb_linearize before trying to access the tag. This patch fixes ksz9477_rcv which is used by the ksz9896 I have at hand, and also applies the same fix to ksz8795_rcv which seems to have the same problem. Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@cherry.de> CC: stable@vger.kernel.org Fixes: 016e43a26b ("net: dsa: ksz: Add KSZ8795 tag code") Fixes: 8b8010fb78 ("dsa: add support for Microchip KSZ tail tagging") Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Link: https://patch.msgid.link/20250515072920.2313014-1-jakob.unterwurzacher@cherry.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2025-09-09 18:44:00 +02:00
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6lowpan
9p
802
8021q	net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime	2025-08-28 16:21:16 +02:00
appletalk	net: appletalk: Fix use-after-free in AARP proxy probe	2025-08-28 16:21:17 +02:00
atm	net: atm: fix memory leak in atm_register_sysfs when device_register fail	2025-09-09 18:43:58 +02:00
ax25	ax25: properly unshare skbs in ax25_kiss_rcv()	2025-09-09 18:43:58 +02:00
batman-adv	batman-adv: fix OOB read/write in network-coding decode	2025-09-09 18:43:59 +02:00
bluetooth	Bluetooth: Fix use-after-free in l2cap_sock_cleanup_listen()	2025-09-09 18:43:57 +02:00
bpf
bpfilter
bridge
caif	caif: reduce stack size, again	2025-08-28 16:21:19 +02:00
can
ceph
core	netpoll: prevent hanging NAPI when netcons gets enabled	2025-08-28 16:21:22 +02:00
dcb
dccp
decnet
dns_resolver
dsa	net: dsa: microchip: linearize skb for tail-tagging switches	2025-09-09 18:44:00 +02:00
ethernet
hsr
ieee802154
ife
ipv4	ipv4: Fix NULL vs error pointer check in inet_blackhole_dev_init()	2025-09-09 18:43:58 +02:00
ipv6	icmp: fix icmp_ndo_send address translation for reply direction	2025-09-09 18:43:57 +02:00
iucv
kcm
key
l2tp
l3mdev
lapb
llc
mac80211	Reapply "wifi: mac80211: Update skb's control block key in ieee80211_tx_dequeue()"	2025-08-28 16:21:20 +02:00
mac802154
mpls
ncsi	net: ncsi: Fix buffer overflow in fetching version id	2025-08-28 16:21:27 +02:00
netfilter	netfilter: conntrack: helper: Replace -EEXIST by -EBUSY	2025-09-09 18:43:57 +02:00
netlabel
netlink	netlink: avoid infinite retry looping in netlink_unicast()	2025-08-28 16:21:23 +02:00
netrom
nfc
nsh
openvswitch
packet	net/packet: fix a race in packet_set_ring() and packet_notifier()	2025-08-28 16:21:23 +02:00
phonet	phonet/pep: Move call to pn_skb_get_dst_sockaddr() earlier in pep_sock_accept()	2025-08-28 16:21:14 +02:00
psample
qrtr
rds
rfkill
rose	rose: fix dangling neighbour pointers in rose_rt_device_down()	2025-07-17 18:25:00 +02:00
rxrpc	rxrpc: Fix oops due to non-existence of prealloc backlog struct	2025-07-17 18:25:02 +02:00
sched	net/sched: Remove unnecessary WARNING condition for empty child qdisc in htb_activate	2025-08-28 16:21:37 +02:00
sctp	sctp: initialize more fields in sctp_v6_from_sk()	2025-09-04 14:05:55 +02:00
smc
strparser
sunrpc
switchdev
tipc	tipc: Fix use-after-free in tipc_conn_close().	2025-07-17 18:25:01 +02:00
tls	bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls	2025-08-28 16:21:19 +02:00
unix
vmw_vsock	vsock: Do not allow binding to VMADDR_PORT_ANY	2025-08-28 16:21:23 +02:00
wimax
wireless	wifi: cfg80211: fix use-after-free in cmp_bss()	2025-09-09 18:43:56 +02:00
x25
xdp
xfrm
compat.c
Kconfig
Makefile
socket.c
sysctl_net.c