CVE-2025-22055: net: fix geneve_opt length integer overflow
In the Linux kernel, the following vulnerability has been resolved:
net: fix geneveopt length integer overflow
struct geneveopt uses 5 bit length for each single option, which means every vary size option should be smaller than 128 bytes.
However, all current related Netlink policies cannot promise this length condition and the attacker can exploit a exact 128-byte size option to fake a zero length option and confuse the parsing logic, further achieve heap out-of-bounds read.
One example crash log is like below:
[ 3.905425] ================================================================== [ 3.905925] BUG: KASAN: slab-out-of-bounds in nlaput+0xa9/0xe0 [ 3.906255] Read of size 124 at addr ffff888005f291cc by task poc/177 [ 3.906646] [ 3.906775] CPU: 0 PID: 177 Comm: poc-oob-read Not tainted 6.1.132 #1 [ 3.907131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 3.907784] Call Trace: [ 3.907925] <TASK> [ 3.908048] dumpstacklvl+0x44/0x5c [ 3.908258] printreport+0x184/0x4be [ 3.909151] kasanreport+0xc5/0x100 [ 3.909539] kasancheckrange+0xf3/0x1a0 [ 3.909794] memcpy+0x1f/0x60 [ 3.909968] nlaput+0xa9/0xe0 [ 3.910147] tunnelkeydump+0x945/0xba0 [ 3.911536] tcfactiondump1+0x1c1/0x340 [ 3.912436] tcfactiondump+0x101/0x180 [ 3.912689] tcfextsdump+0x164/0x1e0 [ 3.912905] fwdump+0x18b/0x2d0 [ 3.913483] tcffillnode+0x2ee/0x460 [ 3.914778] tfilternotify+0xf4/0x180 [ 3.915208] tcnewtfilter+0xd51/0x10d0 [ 3.918615] rtnetlinkrcvmsg+0x4a2/0x560 [ 3.919118] netlinkrcvskb+0xcd/0x200 [ 3.919787] netlinkunicast+0x395/0x530 [ 3.921032] netlinksendmsg+0x3d0/0x6d0 [ 3.921987] socksendmsg+0x99/0xa0 [ 3.922220] syssendto+0x1b7/0x240 [ 3.922682] x64syssendto+0x72/0x90 [ 3.922906] dosyscall64+0x5e/0x90 [ 3.923814] entrySYSCALL64afterhwframe+0x6e/0xd8 [ 3.924122] RIP: 0033:0x7e83eab84407 [ 3.924331] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf [ 3.925330] RSP: 002b:00007ffff505e370 EFLAGS: 00000202 ORIGRAX: 000000000000002c [ 3.925752] RAX: ffffffffffffffda RBX: 00007e83eaafa740 RCX: 00007e83eab84407 [ 3.926173] RDX: 00000000000001a8 RSI: 00007ffff505e3c0 RDI: 0000000000000003 [ 3.926587] RBP: 00007ffff505f460 R08: 00007e83eace1000 R09: 000000000000000c [ 3.926977] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffff505f3c0 [ 3.927367] R13: 00007ffff505f5c8 R14: 00007e83ead1b000 R15: 00005d4fbbe6dcb8
Fix these issues by enforing correct length condition in related policies.
Other sources
In the Linux kernel, the following vulnerability has been resolved:
net: fix geneveopt length integer overflow
struct geneveopt uses 5 bit length for each single option, which means every vary size option should be smaller than 128 bytes.
However, all current related Netlink policies cannot promise this length condition and the attacker can exploit a exact 128-byte size option to fake a zero length option and confuse the parsing logic, further achieve heap out-of-bounds read.
One example crash log is like below:
[ 3.905425] ================================================================== [ 3.905925] BUG: KASAN: slab-out-of-bounds in nlaput+0xa9/0xe0 [ 3.906255] Read of size 124 at addr ffff888005f291cc by task poc/177 [ 3.906646] [ 3.906775] CPU: 0 PID: 177 Comm: poc-oob-read Not tainted 6.1.132 #1 [ 3.907131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 3.907784] Call Trace: [ 3.907925] <TASK> [ 3.908048] dumpstacklvl+0x44/0x5c [ 3.908258] printreport+0x184/0x4be [ 3.909151] kasanreport+0xc5/0x100 [ 3.909539] kasancheckrange+0xf3/0x1a0 [ 3.909794] memcpy+0x1f/0x60 [ 3.909968] nlaput+0xa9/0xe0 [ 3.910147] tunnelkeydump+0x945/0xba0 [ 3.911536] tcfactiondump1+0x1c1/0x340 [ 3.912436] tcfactiondump+0x101/0x180 [ 3.912689] tcfextsdump+0x164/0x1e0 [ 3.912905] fwdump+0x18b/0x2d0 [ 3.913483] tcffillnode+0x2ee/0x460 [ 3.914778] tfilternotify+0xf4/0x180 [ 3.915208] tcnewtfilter+0xd51/0x10d0 [ 3.918615] rtnetlinkrcvmsg+0x4a2/0x560 [ 3.919118] netlinkrcvskb+0xcd/0x200 [ 3.919787] netlinkunicast+0x395/0x530 [ 3.921032] netlinksendmsg+0x3d0/0x6d0 [ 3.921987] socksendmsg+0x99/0xa0 [ 3.922220] syssendto+0x1b7/0x240 [ 3.922682] x64syssendto+0x72/0x90 [ 3.922906] dosyscall64+0x5e/0x90 [ 3.923814] entrySYSCALL64afterhwframe+0x6e/0xd8 [ 3.924122] RIP: 0033:0x7e83eab84407 [ 3.924331] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf [ 3.925330] RSP: 002b:00007ffff505e370 EFLAGS: 00000202 ORIGRAX: 000000000000002c [ 3.925752] RAX: ffffffffffffffda RBX: 00007e83eaafa740 RCX: 00007e83eab84407 [ 3.926173] RDX: 00000000000001a8 RSI: 00007ffff505e3c0 RDI: 0000000000000003 [ 3.926587] RBP: 00007ffff505f460 R08: 00007e83eace1000 R09: 000000000000000c [ 3.926977] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffff505f3c0 [ 3.927367] R13: 00007ffff505f5c8 R14: 00007e83ead1b000 R15: 00005d4fbbe6dcb8
Fix these issues by enforing correct length condition in related policies.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Fix/implement correct length-condition enforcement in the geneve option parsing logic: since struct geneve_opt uses 5 bit length for each single option, prevent acceptance/parsing of an option whose effective length is 128 bytes or more; reject or clamp lengths so that every variable-size option is smaller than 128 bytes. This addresses "option to *fake* a zero length option and confuse the parsing logic" and the "length integer overflow" described for "net: fix geneve_opt length integer overflow".
Geneve (geneve_opt) Netlink/packet option parsing geneve_opt length field (5-bit per single option) = enforce decoded option length to be < 128 bytes (attacker can exploit an exact 128-byte size; ensure any variable-length option is smaller than 128 bytes).
Event History
Frequently Asked Questions
What is the severity of CVE-2025-22055?
CVE-2025-22055 has been classified with a high-severity level due to its potential for integer overflow exploits.
How do I fix CVE-2025-22055?
To fix CVE-2025-22055, update to the latest patched version of the Linux kernel provided by your distribution.
What does CVE-2025-22055 affect?
CVE-2025-22055 affects the Linux kernel, specifically the handling of geneve_opt structures in netlink communication.
What vulnerability does CVE-2025-22055 address?
CVE-2025-22055 addresses an integer overflow vulnerability in geneve_opt length processing.
Is CVE-2025-22055 a critical vulnerability?
While not classified as critical, CVE-2025-22055 is significant and can lead to serious security issues if exploited.