6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit b9653d19e556c6afd035602927a93d100a0d7644 ]
syzbot is able to feed a packet with 14 bytes, pretending
it is a vlan one.
Since fill_frame_info() is relying on skb->mac_len already,
extend the check to cover this case.
BUG: KMSAN: uninit-value in fill_frame_info net/hsr/hsr_forward.c:709 [inline]
BUG: KMSAN: uninit-value in hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
fill_frame_info net/hsr/hsr_forward.c:709 [inline]
hsr_forward_skb+0x9ee/0x3b10 net/hsr/hsr_forward.c:724
hsr_dev_xmit+0x2f0/0x350 net/hsr/hsr_device.c:235
__netdev_start_xmit include/linux/netdevice.h:5002 [inline]
netdev_start_xmit include/linux/netdevice.h:5011 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3606
__dev_queue_xmit+0x366a/0x57d0 net/core/dev.c:4434
dev_queue_xmit include/linux/netdevice.h:3168 [inline]
packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276
packet_snd net/packet/af_packet.c:3146 [inline]
packet_sendmsg+0x91ae/0xa6f0 net/packet/af_packet.c:3178
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:726
__sys_sendto+0x594/0x750 net/socket.c:2197
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
slab_post_alloc_hook mm/slub.c:4091 [inline]
slab_alloc_node mm/slub.c:4134 [inline]
kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4186
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:587
__alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
alloc_skb include/linux/skbuff.h:1323 [inline]
alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612
sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881
packet_alloc_skb net/packet/af_packet.c:2995 [inline]
packet_snd net/packet/af_packet.c:3089 [inline]
packet_sendmsg+0x74c6/0xa6f0 net/packet/af_packet.c:3178
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x30f/0x380 net/socket.c:726
__sys_sendto+0x594/0x750 net/socket.c:2197
__do_sys_sendto net/socket.c:2204 [inline]
__se_sys_sendto net/socket.c:2200 [inline]
__x64_sys_sendto+0x125/0x1d0 net/socket.c:2200
x64_sys_call+0x346a/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:45
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: 48b491a5cc74 ("net: hsr: fix mac_len checks")
Reported-by: syzbot+671e2853f9851d039551@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://lore.kernel.org/netdev/6745dc7f.050a0220.21d33d.0018.GAE@xxxxxxxxxx/T/#u
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: WingMan Kwok <w-kwok2@xxxxxx>
Cc: Murali Karicheri <m-karicheri2@xxxxxx>
Cc: MD Danish Anwar <danishanwar@xxxxxx>
Cc: Jiri Pirko <jiri@xxxxxxxxxx>
Cc: George McCollister <george.mccollister@xxxxxxxxx>
Link: https://patch.msgid.link/20241126144344.4177332-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/hsr/hsr_forward.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index 0323ab5023c69..2790f3964d6bd 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -588,6 +588,8 @@ static int fill_frame_info(struct hsr_frame_info *frame,
frame->is_vlan = true;
if (frame->is_vlan) {
+ if (skb->mac_len < offsetofend(struct hsr_vlan_ethhdr, vlanhdr))
+ return -EINVAL;
vlan_hdr = (struct hsr_vlan_ethhdr *)ethhdr;
proto = vlan_hdr->vlanhdr.h_vlan_encapsulated_proto;
/* FIXME: */
--
2.43.0
