diff options
| author | Fernando Fernandez Mancera <fmancera@suse.de> | 2026-03-04 15:09:35 +0100 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2026-03-09 15:14:46 +0100 |
| commit | 0b352f83cabfefdaafa806d6471f0eca117dc7d5 (patch) | |
| tree | b8138c6f862e2122c083b43ef42c339c1db6b8d7 /net/xfrm | |
| parent | 0d10393d5eac33cbd92f7a41fddca12c41d3cb7e (diff) | |
xfrm: iptfs: fix skb_put() panic on non-linear skb during reassembly
In iptfs_reassem_cont(), IP-TFS attempts to append data to the new inner
packet 'newskb' that is being reassembled. First a zero-copy approach is
tried if it succeeds then newskb becomes non-linear.
When a subsequent fragment in the same datagram does not meet the
fast-path conditions, a memory copy is performed. It calls skb_put() to
append the data and as newskb is non-linear it triggers
SKB_LINEAR_ASSERT check.
Oops: invalid opcode: 0000 [#1] SMP NOPTI
[...]
RIP: 0010:skb_put+0x3c/0x40
[...]
Call Trace:
<IRQ>
iptfs_reassem_cont+0x1ab/0x5e0 [xfrm_iptfs]
iptfs_input_ordered+0x2af/0x380 [xfrm_iptfs]
iptfs_input+0x122/0x3e0 [xfrm_iptfs]
xfrm_input+0x91e/0x1a50
xfrm4_esp_rcv+0x3a/0x110
ip_protocol_deliver_rcu+0x1d7/0x1f0
ip_local_deliver_finish+0xbe/0x1e0
__netif_receive_skb_core.constprop.0+0xb56/0x1120
__netif_receive_skb_list_core+0x133/0x2b0
netif_receive_skb_list_internal+0x1ff/0x3f0
napi_complete_done+0x81/0x220
virtnet_poll+0x9d6/0x116e [virtio_net]
__napi_poll.constprop.0+0x2b/0x270
net_rx_action+0x162/0x360
handle_softirqs+0xdc/0x510
__irq_exit_rcu+0xe7/0x110
irq_exit_rcu+0xe/0x20
common_interrupt+0x85/0xa0
</IRQ>
<TASK>
Fix this by checking if the skb is non-linear. If it is, linearize it by
calling skb_linearize(). As the initial allocation of newskb originally
reserved enough tailroom for the entire reassembled packet we do not
need to check if we have enough tailroom or extend it.
Fixes: 5f2b6a909574 ("xfrm: iptfs: add skb-fragment sharing code")
Reported-by: Hao Long <me@imlonghao.com>
Closes: https://lore.kernel.org/netdev/DGRCO9SL0T5U.JTINSHJQ9KPK@imlonghao.com/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
| -rw-r--r-- | net/xfrm/xfrm_iptfs.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_iptfs.c b/net/xfrm/xfrm_iptfs.c index 0747d1cfa333..2c87290fe06c 100644 --- a/net/xfrm/xfrm_iptfs.c +++ b/net/xfrm/xfrm_iptfs.c @@ -901,6 +901,12 @@ static u32 iptfs_reassem_cont(struct xfrm_iptfs_data *xtfs, u64 seq, iptfs_skb_can_add_frags(newskb, fragwalk, data, copylen)) { iptfs_skb_add_frags(newskb, fragwalk, data, copylen); } else { + if (skb_linearize(newskb)) { + XFRM_INC_STATS(xs_net(xtfs->x), + LINUX_MIB_XFRMINBUFFERERROR); + goto abandon; + } + /* copy fragment data into newskb */ if (skb_copy_seq_read(st, data, skb_put(newskb, copylen), copylen)) { |