High · published September 17, 2025
In the Linux kernel, the following vulnerability has been resolved:
skbuff: Account for tail adjustment during pull operations
Extending the tail can have some unexpected side effects if a program uses
a helper like BPF_FUNC_skb_pull_data to read partial content beyond the
head skb headlen when all the skbs in the gso frag_list are linear with no
head_frag -
kernel BUG at net/core/skbuff.c:4219!
pc : skb_segment+0xcf4/0xd2c
lr : skb_segment+0x63c/0xd2c
Call trace:
skb_segment+0xcf4/0xd2c
__udp_gso_segment+0xa4/0x544
udp4_ufo_fragment+0x184/0x1c0
inet_gso_segment+0x16c/0x3a4
skb_mac_gso_segment+0xd4/0x1b0
__skb_gso_segment+0xcc/0x12c
udp_rcv_segment+0x54/0x16c
udp_queue_rcv_skb+0x78/0x144
udp_unicast_rcv_skb+0x8c/0xa4
__udp4_lib_rcv+0x490/0x68c
udp_rcv+0x20/0x30
ip_protocol_deliver_rcu+0x1b0/0x33c
ip_local_deliver+0xd8/0x1f0
ip_rcv+0x98/0x1a4
deliver_ptype_list_skb+0x98/0x1ec
__netif_receive_skb_core+0x978/0xc60
Fix this by marking these skbs as GSO_DODGY so segmentation can handle
the tail updates accordingly.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 4.9.194, < 4.9.337 | 4.9.337 |
| linux/linux_kernel | ≥ 4.14.145, < 4.14.303 | 4.14.303 |
| linux/linux_kernel | ≥ 4.19.74, < 4.19.270 | 4.19.270 |
| linux/linux_kernel | ≥ 5.2.16, < 5.3 | 5.3 |
| linux/linux_kernel | ≥ 5.3.1, < 5.4.229 | 5.4.229 |
| linux/linux_kernel | ≥ 5.5, < 5.10.163 | 5.10.163 |
| linux/linux_kernel | ≥ 5.11, < 5.15.86 | 5.15.86 |
| linux/linux_kernel | ≥ 5.16, < 6.0.16 | 6.0.16 |
| linux/linux_kernel | ≥ 6.1, < 6.1.2 | 6.1.2 |
| linux/linux_kernel | all versions | — |