CVE-2026-23095

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-23095
In the Linux kernel, the following vulnerability has been resolved: gue: Fix skb memleak with inner IP protocol 0. syzbot reported skb memleak below. [0] The repro generated a GUE packet with its inner protocol 0. gue_udp_recv() returns -guehdr->proto_ctype for "resubmit" in ip_protocol_deliver_rcu(), but this only works with non-zero protocol number. Let's drop such packets. Note that 0 is a valid number (IPv6 Hop-by-Hop Option). I think it is not practical to encap HOPOPT in GUE, so once someone starts to complain, we could pass down a resubmit flag pointer to distinguish two zeros from the upper layer: * no error * resubmit HOPOPT [0] BUG: memory leak unreferenced object 0xffff888109695a00 (size 240): comm "syz.0.17", pid 6088, jiffies 4294943096 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 40 c2 10 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. backtrace (crc a84b336f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5270 __build_skb+0x23/0x60 net/core/skbuff.c:474 build_skb+0x20/0x190 net/core/skbuff.c:490 __tun_build_skb drivers/net/tun.c:1541 [inline] tun_build_skb+0x4a1/0xa40 drivers/net/tun.c:1636 tun_get_user+0xc12/0x2030 drivers/net/tun.c:1770 tun_chr_write_iter+0x71/0x120 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0xa7/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/380a82d36e37db49fd41ecc378c22fd29392e96a Patch
https://git.kernel.org/stable/c/536f5bbc322eb1e175bdd1ced22b236a951c4d8f Patch
https://git.kernel.org/stable/c/5437a279804ced8088cabb945dba88a26d828f8c Patch
https://git.kernel.org/stable/c/886f186328b718400dbf79e1bc8cbcbd710ab766 Patch
https://git.kernel.org/stable/c/9a56796ad258786d3624eef5aefba394fc9bdded Patch
https://git.kernel.org/stable/c/ce569b389a5c78d64788a5ea94560e17fa574b35 Patch
https://git.kernel.org/stable/c/f87b9b7a618c82e7465e872eb10e14c803871892 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*
History

03 Apr 2026, 14:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : 5.5 		v2 : unknown
v3 : 7.5

18 Mar 2026, 13:36

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/380a82d36e37db49fd41ecc378c22fd29392e96a - () https://git.kernel.org/stable/c/380a82d36e37db49fd41ecc378c22fd29392e96a - Patch
References () https://git.kernel.org/stable/c/536f5bbc322eb1e175bdd1ced22b236a951c4d8f - () https://git.kernel.org/stable/c/536f5bbc322eb1e175bdd1ced22b236a951c4d8f - Patch
References () https://git.kernel.org/stable/c/5437a279804ced8088cabb945dba88a26d828f8c - () https://git.kernel.org/stable/c/5437a279804ced8088cabb945dba88a26d828f8c - Patch
References () https://git.kernel.org/stable/c/886f186328b718400dbf79e1bc8cbcbd710ab766 - () https://git.kernel.org/stable/c/886f186328b718400dbf79e1bc8cbcbd710ab766 - Patch
References () https://git.kernel.org/stable/c/9a56796ad258786d3624eef5aefba394fc9bdded - () https://git.kernel.org/stable/c/9a56796ad258786d3624eef5aefba394fc9bdded - Patch
References () https://git.kernel.org/stable/c/ce569b389a5c78d64788a5ea94560e17fa574b35 - () https://git.kernel.org/stable/c/ce569b389a5c78d64788a5ea94560e17fa574b35 - Patch
References () https://git.kernel.org/stable/c/f87b9b7a618c82e7465e872eb10e14c803871892 - () https://git.kernel.org/stable/c/f87b9b7a618c82e7465e872eb10e14c803871892 - Patch
Summary
  • (es) En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: gue: Corrige la fuga de memoria de skb con el protocolo IP interno 0. syzbot informó de una fuga de memoria de skb a continuación. [0] La reproducción generó un paquete GUE con su protocolo interno 0. gue_udp_recv() devuelve -guehdr->proto_ctype para 'resubmit' en ip_protocol_deliver_rcu(), pero esto solo funciona con números de protocolo distintos de cero. Descartemos tales paquetes. Tenga en cuenta que 0 es un número válido (Opción Salto a Salto de IPv6). Creo que no es práctico encapsular HOPOPT en GUE, así que una vez que alguien empiece a quejarse, podríamos pasar un puntero de bandera de reenvío para distinguir dos ceros de la capa superior: * sin error * reenviar HOPOPT [0] BUG: fuga de memoria objeto sin referencia 0xffff888109695a00 (tamaño 240): comm 'syz.0.17', pid 6088, jiffies 4294943096 volcado hexadecimal (primeros 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 40 c2 10 81 88 ff ff 00 00 00 00 00 00 00 00 .@.............. rastreo (crc a84b336f): kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline] slab_post_alloc_hook mm/slub.c:4958 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x3b4/0x590 mm/slub.c:5270 __build_skb+0x23/0x60 net/core/skbuff.c:474 build_skb+0x20/0x190 net/core/skbuff.c:490 __tun_build_skb drivers/net/tun.c:1541 [inline] tun_build_skb+0x4a1/0xa40 drivers/net/tun.c:1636 tun_get_user+0xc12/0x2030 drivers/net/tun.c:1770 tun_chr_write_iter+0x71/0x120 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x45d/0x710 fs/read_write.c:686 ksys_write+0xa7/0x170 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
CPE cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:*
CWE CWE-401
First Time Linux
Linux linux Kernel

06 Feb 2026, 17:16

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/380a82d36e37db49fd41ecc378c22fd29392e96a -
  • () https://git.kernel.org/stable/c/536f5bbc322eb1e175bdd1ced22b236a951c4d8f -
  • () https://git.kernel.org/stable/c/886f186328b718400dbf79e1bc8cbcbd710ab766 -

04 Feb 2026, 17:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-02-04 17:16

Updated : 2026-04-03 14:16

NVD link : CVE-2026-23095

Mitre link : CVE-2026-23095

CVE.ORG link : CVE-2026-23095

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-401

Missing Release of Memory after Effective Lifetime