CVE-2025-38124

Commit a1e40ac5b5e9 ("net: gso: fix udp gso fraglist segmentation after pull from fraglist") detected invalid geometry in fraglist skbs and redirects them from skbsegmentlist to more robust skbsegment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skbsegment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust.

If only part of the fraglist payload is pulled into headskb, it will always cause exception when splitting skbs by skbsegment. For detailed call stack information, see below.

Valid SKBGSOFRAGLIST skbs - consist of two or more segments - the headskb holds the protocol headers plus first gsosize - one or more fraglist skbs hold exactly one segment - all but the last must be gsosize

Optional datapath hooks such as NAT and BPF (bpfskbpull_data) can modify fraglist skbs, breaking these invariants.

In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes.

The skbs no longer meets the above SKBGSOFRAGLIST conditions because payload was pulled into headskb, it needs to be linearized before pass to regular skbsegment.

skb_segment+0xcd0/0xd14
__udp_gso_segment+0x334/0x5f4
udp4_ufo_fragment+0x118/0x15c
inet_gso_segment+0x164/0x338
skb_mac_gso_segment+0xc4/0x13c
__skb_gso_segment+0xc4/0x124
validate_xmit_skb+0x9c/0x2c0
validate_xmit_skb_list+0x4c/0x80
sch_direct_xmit+0x70/0x404
__dev_queue_xmit+0x64c/0xe5c
neigh_resolve_output+0x178/0x1c4
ip_finish_output2+0x37c/0x47c
__ip_finish_output+0x194/0x240
ip_finish_output+0x20/0xf4
ip_output+0x100/0x1a0
NF_HOOK+0xc4/0x16c
ip_forward+0x314/0x32c
ip_rcv+0x90/0x118
__netif_receive_skb+0x74/0x124
process_backlog+0xe8/0x1a4
__napi_poll+0x5c/0x1f8
net_rx_action+0x154/0x314
handle_softirqs+0x154/0x4b8

[118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278!
[118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000
[118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000
[118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO)
[118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14
[118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14
[118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770

References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

080e6c9a3908de193a48f646c5ce1bfb15676ffc

Fixed

0e65f38bd1aa14ea86e221b7bb814d38278d86c3

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

af3122f5fdc0d00581d6e598a668df6bf54c9daa

Fixed

85eef1748c024da1a191aed56b30a3a65958c50c

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

a1e40ac5b5e9077fe1f7ae0eb88034db0f9ae1ab

Fixed

4399f59a9467a324ed46657555f0e1f209a14acb

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

a1e40ac5b5e9077fe1f7ae0eb88034db0f9ae1ab

Fixed

a04302867094bdc6efac1b598370fc47cf3f2388

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

a1e40ac5b5e9077fe1f7ae0eb88034db0f9ae1ab

Fixed

3382a1ed7f778db841063f5d7e317ac55f9e7f72

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

33e28acf42ee863f332a958bfc2f1a284a3659df

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

3cd00d2e3655fad3bda96dc1ebf17b6495f86fea

Affected versions

v5.*

v5.10.1

v5.10.10

v5.10.11

v5.10.12

v5.10.13

v5.10.14

v5.10.15

v5.10.16

v5.10.17

v5.10.18

v5.10.19

v5.10.2

v5.10.3

v5.10.4

v5.10.5

v5.10.6

v5.10.7

v5.10.8

v5.10.9

v5.11.1

v5.11.10

v5.11.11

v5.11.12

v5.11.13

v5.11.14

v5.11.15

v5.11.16

v5.11.17

v5.11.18

v5.11.19

v5.11.2

v5.11.20

v5.11.21

v5.11.3

v5.11.4

v5.11.5

v5.11.6

v5.11.7

v5.11.8

v5.11.9

v5.12.1

v5.12.10

v5.12.11

v5.12.12

v5.12.13

v5.12.14

v5.12.15

v5.12.16

v5.12.17

v5.12.18

v5.12.19

v5.12.2

v5.12.3

v5.12.4

v5.12.5

v5.12.6

v5.12.7

v5.12.8

v5.12.9

v5.13.1

v5.13.10

v5.13.11

v5.13.12

v5.13.13

v5.13.14

v5.13.15

v5.13.16

v5.13.17

v5.13.18

v5.13.2

v5.13.3

v5.13.4

v5.13.5

v5.13.6

v5.13.7

v5.13.8

v5.13.9

v5.14.1

v5.14.10

v5.14.11

v5.14.12

v5.14.13

v5.14.14

v5.14.15

v5.14.16

v5.14.17

v5.14.18

v5.14.19

v5.14.2

v5.14.20

v5.14.3

v5.14.4

v5.14.5

v5.14.6

v5.14.7

v5.14.8

v5.14.9

v5.15.1

v5.15.10

v5.15.11

v5.15.12

v5.15.13

v5.15.14

v5.15.15

v5.15.16

v5.15.17

v5.15.18

v5.15.19

v5.15.2

v5.15.3

v5.15.4

v5.15.5

v5.15.6

v5.15.7

v5.15.8

v5.15.9

v5.16.1

v5.16.10

v5.16.11

v5.16.12

v5.16.13

v5.16.14

v5.16.15

v5.16.16

v5.16.17

v5.16.18

v5.16.19

v5.16.2

v5.16.20

v5.16.3

v5.16.4

v5.16.5

v5.16.6

v5.16.7

v5.16.8

v5.16.9

v5.17.1

v5.17.10

v5.17.11

v5.17.12

v5.17.13

v5.17.14

v5.17.2

v5.17.3

v5.17.4

v5.17.5

v5.17.6

v5.17.7

v5.17.8

v5.17.9

v5.18.1

v5.18.10

v5.18.11

v5.18.12

v5.18.13

v5.18.14

v5.18.15

v5.18.16

v5.18.17

v5.18.18

v5.18.19

v5.18.2

v5.18.3

v5.18.4

v5.18.5

v5.18.6

v5.18.7

v5.18.8

v5.18.9

v5.19.1

v5.19.10

v5.19.11

v5.19.12

v5.19.13

v5.19.14

v5.19.15

v5.19.16

v5.19.2

v5.19.3

v5.19.4

v5.19.5

v5.19.6

v5.19.7

v5.19.8

v5.19.9

v5.6.1

v5.6.10

v5.6.11

v5.6.12

v5.6.13

v5.6.14

v5.6.15

v5.6.16

v5.6.17

v5.6.18

v5.6.2

v5.6.3

v5.6.4

v5.6.5

v5.6.6

v5.6.7

v5.6.8

v5.6.9

v5.7.1

v5.7.10

v5.7.11

v5.7.12

v5.7.13

v5.7.14

v5.7.15

v5.7.16

v5.7.2

v5.7.3

v5.7.4

v5.7.5

v5.7.6

v5.7.7

v5.7.8

v5.7.9

v5.8.1

v5.8.10

v5.8.11

v5.8.12

v5.8.13

v5.8.14

v5.8.15

v5.8.16

v5.8.17

v5.8.18

v5.8.2

v5.8.3

v5.8.4

v5.8.5

v5.8.6

v5.8.7

v5.8.8

v5.8.9

v5.9.1

v5.9.10

v5.9.11

v5.9.12

v5.9.13

v5.9.14

v5.9.15

v5.9.16

v5.9.2

v5.9.3

v5.9.4

v5.9.5

v5.9.6

v5.9.7

v5.9.8

v5.9.9

v6.*

v6.0.1

v6.0.10

v6.0.11

v6.0.12

v6.0.13

v6.0.14

v6.0.15

v6.0.16

v6.0.17

v6.0.18

v6.0.2

v6.0.3

v6.0.4

v6.0.5

v6.0.6

v6.0.7

v6.0.8

v6.0.9

v6.1.1

v6.1.10

v6.1.11

v6.1.113

v6.1.114

v6.1.115

v6.1.116

v6.1.117

v6.1.118

v6.1.119

v6.1.12

v6.1.120

v6.1.121

v6.1.122

v6.1.123

v6.1.124

v6.1.125

v6.1.126

v6.1.127

v6.1.128

v6.1.129

v6.1.13

v6.1.130

v6.1.131

v6.1.132

v6.1.133

v6.1.134

v6.1.135

v6.1.136

v6.1.137

v6.1.138

v6.1.139

v6.1.14

v6.1.140

v6.1.141

v6.1.15

v6.1.2

v6.1.3

v6.1.4

v6.1.5

v6.1.6

v6.1.7

v6.1.8

v6.1.9

v6.10.1

v6.10.10

v6.10.11

v6.10.12

v6.10.13

v6.10.14

v6.10.2

v6.10.3

v6.10.4

v6.10.5

v6.10.6

v6.10.7

v6.10.8

v6.10.9

v6.11.10

v6.11.11

v6.11.3

v6.11.4

v6.11.5

v6.11.6

v6.11.7

v6.11.8

v6.11.9

v6.12

v6.12-rc1

v6.12-rc2

v6.12-rc3

v6.12-rc4

v6.12-rc5

v6.12-rc6

v6.12-rc7

v6.12.1

v6.12.10

v6.12.11

v6.12.12

v6.12.13

v6.12.14

v6.12.15

v6.12.16

v6.12.17

v6.12.18

v6.12.19

v6.12.2

v6.12.20

v6.12.21

v6.12.22

v6.12.23

v6.12.24

v6.12.25

v6.12.26

v6.12.27

v6.12.28

v6.12.29

v6.12.3

v6.12.30

v6.12.31

v6.12.32

v6.12.33

v6.12.4

v6.12.5

v6.12.6

v6.12.7

v6.12.8

v6.12.9

v6.13

v6.13-rc1

v6.13-rc2

v6.13-rc3

v6.13-rc4

v6.13-rc5

v6.13-rc6

v6.13-rc7

v6.13.1

v6.13.10

v6.13.11

v6.13.12

v6.13.2

v6.13.3

v6.13.4

v6.13.5

v6.13.6

v6.13.7

v6.13.8

v6.13.9

v6.14

v6.14-rc1

v6.14-rc2

v6.14-rc3

v6.14-rc4

v6.14-rc5

v6.14-rc6

v6.14-rc7

v6.14.1

v6.14.10

v6.14.11

v6.14.2

v6.14.3

v6.14.4

v6.14.5

v6.14.6

v6.14.7

v6.14.8

v6.14.9

v6.15

v6.15-rc1

v6.15-rc2

v6.15-rc3

v6.15-rc4

v6.15-rc5

v6.15-rc6

v6.15-rc7

v6.15.1

v6.15.10

v6.15.11

v6.15.2

v6.15.3

v6.15.4

v6.15.5

v6.15.6

v6.15.7

v6.15.8

v6.15.9

v6.16

v6.16-rc1

v6.16-rc2

v6.16-rc3

v6.16-rc4

v6.16-rc5

v6.16-rc6

v6.16-rc7

v6.16.1

v6.16.10

v6.16.11

v6.16.12

v6.16.2

v6.16.3

v6.16.4

v6.16.5

v6.16.6

v6.16.7

v6.16.8

v6.16.9

v6.17

v6.17-rc1

v6.17-rc2

v6.17-rc3

v6.17-rc4

v6.17-rc5

v6.17-rc6

v6.17-rc7

v6.17.1

v6.17.2

v6.17.3

v6.2.1

v6.2.10

v6.2.11

v6.2.12

v6.2.13

v6.2.14

v6.2.15

v6.2.2

v6.2.3

v6.2.4

v6.2.5

v6.2.6

v6.2.7

v6.2.8

v6.2.9

v6.3.1

v6.3.10

v6.3.11

v6.3.12

v6.3.2

v6.3.3

v6.3.4

v6.3.5

v6.3.6

v6.3.7

v6.3.8

v6.3.9

v6.4.1

v6.4.10

v6.4.11

v6.4.12

v6.4.13

v6.4.14

v6.4.15

v6.4.16

v6.4.2

v6.4.3

v6.4.4

v6.4.5

v6.4.6

v6.4.7

v6.4.8

v6.4.9

v6.5.1

v6.5.10

v6.5.11

v6.5.12

v6.5.13

v6.5.2

v6.5.3

v6.5.4

v6.5.5

v6.5.6

v6.5.7

v6.5.8

v6.5.9

v6.6.1

v6.6.10

v6.6.11

v6.6.12

v6.6.13

v6.6.14

v6.6.2

v6.6.3

v6.6.4

v6.6.5

v6.6.55

v6.6.56

v6.6.57

v6.6.58

v6.6.59

v6.6.6

v6.6.60

v6.6.61

v6.6.62

v6.6.63

v6.6.64

v6.6.65

v6.6.66

v6.6.67

v6.6.68

v6.6.69

v6.6.7

v6.6.70

v6.6.71

v6.6.72

v6.6.73

v6.6.74

v6.6.75

v6.6.76

v6.6.77

v6.6.78

v6.6.79

v6.6.8

v6.6.80

v6.6.81

v6.6.82

v6.6.83

v6.6.84

v6.6.85

v6.6.86

v6.6.87

v6.6.88

v6.6.89

v6.6.9

v6.6.90

v6.6.91

v6.6.92

v6.6.93

v6.7.1

v6.7.10

v6.7.11

v6.7.2

v6.7.3

v6.7.4

v6.7.5

v6.7.6

v6.7.7

v6.7.8

v6.7.9

v6.8.1

v6.8.10

v6.8.11

v6.8.2

v6.8.3

v6.8.4

v6.8.5

v6.8.6

v6.8.7

v6.8.8

v6.8.9

v6.9.1

v6.9.10

v6.9.11

v6.9.12

v6.9.2

v6.9.3

v6.9.4

v6.9.5

v6.9.6

v6.9.7

v6.9.8

v6.9.9

Linux / Kernel

Package

Name: Kernel

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.1.142

Type: ECOSYSTEM
Events: Introduced

6.2.0

Fixed

6.6.94

Type: ECOSYSTEM
Events: Introduced

6.7.0

Fixed

6.12.34

Type: ECOSYSTEM
Events: Introduced

6.12.0

Fixed

6.15.3