FKIE_CVE-2026-64436
Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: af_key: initialize alg_key_len for IPComp states
pfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by
allocating x->calg and copying only the algorithm name:
x->calg = kmalloc_obj(*x->calg);
if (!x->calg) {
err = -ENOMEM;
goto out;
}
strcpy(x->calg->alg_name, a->name);
x->props.calgo = sa->sadb_sa_encrypt;
Unlike the authentication (x->aalg) and encryption (x->ealg) branches of
the same function, the compression branch never initializes
calg->alg_key_len. IPComp carries no key and the allocation only
reserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field
is left containing uninitialized slab data.
calg->alg_key_len is later used as a length by xfrm_algo_clone() when an
IPComp state is cloned during XFRM_MSG_MIGRATE:
xfrm_state_migrate()
xfrm_state_clone_and_setup()
x->calg = xfrm_algo_clone(orig->calg);
kmemdup(orig, xfrm_alg_len(orig));
where xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With
a non-zero garbage alg_key_len, kmemdup() reads past the end of the
68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating
it triggers (net-next, KASAN, init_on_alloc=0):
BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60
Read of size 4164 at addr ff11000025a74980 by task diag2/9287
CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1
Call Trace:
<TASK>
dump_stack_lvl+0x10e/0x1f0
print_report+0xf7/0x600
kasan_report+0xe4/0x120
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x23/0x60
kmemdup_noprof+0x44/0x60
xfrm_state_migrate+0x70a/0x1da0
xfrm_migrate+0x753/0x18a0
xfrm_do_migrate+0xb47/0xf10
xfrm_user_rcv_msg+0x411/0xb50
netlink_rcv_skb+0x158/0x420
xfrm_netlink_rcv+0x71/0x90
netlink_unicast+0x584/0x850
netlink_sendmsg+0x8b0/0xdc0
____sys_sendmsg+0x9f7/0xb90
___sys_sendmsg+0x134/0x1d0
__sys_sendmsg+0x16d/0x220
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Allocated by task 9287:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
pfkey_add+0x2652/0x2ea0
pfkey_process+0x6d0/0x830
pfkey_sendmsg+0x42c/0x850
__sys_sendto+0x461/0x4b0
__x64_sys_sendto+0xe0/0x1c0
do_syscall_64+0x116/0x7d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ff11000025a74980
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
allocated 68-byte region [ff11000025a74980, ff11000025a749c4)
Depending on the uninitialized value the same field can instead request
an oversized kmemdup() allocation and make the migration clone fail.
The XFRM netlink path is not affected: verify_one_alg() rejects an
XFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via
XFRM_MSG_NEWSA is always self-consistent.
Initialize calg->alg_key_len to 0, matching the aalg/ealg branches.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/key/af_key.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "58e82fc3dedb57b1432292504415b224fd2d6acb",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "01b9115b55018123ef2449ac4951f89147a8428e",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "3f63d1752d90c0e28be931a48ab5d89bc97d637d",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "273c06b81d2e902b21acc801ae18c8276c8a9b69",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "6de2a650917bedaaefd65b17cede83c5e2c1dedd",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "e8417353cbd078d10531ba3928e609c84ab09e6b",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
},
{
"lessThan": "d129c3177d7b1138fd5066fcc63a698b3ba415b0",
"status": "affected",
"version": "80c9abaabf4283f7cf4a0b3597cd302506635b7f",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/key/af_key.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.21"
},
{
"lessThan": "2.6.21",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: af_key: initialize alg_key_len for IPComp states\n\npfkey_msg2xfrm_state() handles the IPComp (SADB_X_SATYPE_IPCOMP) case by\nallocating x-\u003ecalg and copying only the algorithm name:\n\n\tx-\u003ecalg = kmalloc_obj(*x-\u003ecalg);\n\tif (!x-\u003ecalg) {\n\t\terr = -ENOMEM;\n\t\tgoto out;\n\t}\n\tstrcpy(x-\u003ecalg-\u003ealg_name, a-\u003ename);\n\tx-\u003eprops.calgo = sa-\u003esadb_sa_encrypt;\n\nUnlike the authentication (x-\u003eaalg) and encryption (x-\u003eealg) branches of\nthe same function, the compression branch never initializes\ncalg-\u003ealg_key_len. IPComp carries no key and the allocation only\nreserves sizeof(struct xfrm_algo) (i.e. no room for a key), so the field\nis left containing uninitialized slab data.\n\ncalg-\u003ealg_key_len is later used as a length by xfrm_algo_clone() when an\nIPComp state is cloned during XFRM_MSG_MIGRATE:\n\n\txfrm_state_migrate()\n\t xfrm_state_clone_and_setup()\n\t x-\u003ecalg = xfrm_algo_clone(orig-\u003ecalg);\n\t kmemdup(orig, xfrm_alg_len(orig));\n\nwhere xfrm_alg_len() returns sizeof(*alg) + (alg_key_len + 7) / 8. With\na non-zero garbage alg_key_len, kmemdup() reads past the end of the\n68-byte calg object. Adding an IPComp SA via PF_KEY and then migrating\nit triggers (net-next, KASAN, init_on_alloc=0):\n\n BUG: KASAN: slab-out-of-bounds in kmemdup_noprof+0x44/0x60\n Read of size 4164 at addr ff11000025a74980 by task diag2/9287\n CPU: 3 UID: 0 PID: 9287 Comm: diag2 7.1.0-rc6-g903db046d557 #1\n Call Trace:\n \u003cTASK\u003e\n dump_stack_lvl+0x10e/0x1f0\n print_report+0xf7/0x600\n kasan_report+0xe4/0x120\n kasan_check_range+0x105/0x1b0\n __asan_memcpy+0x23/0x60\n kmemdup_noprof+0x44/0x60\n xfrm_state_migrate+0x70a/0x1da0\n xfrm_migrate+0x753/0x18a0\n xfrm_do_migrate+0xb47/0xf10\n xfrm_user_rcv_msg+0x411/0xb50\n netlink_rcv_skb+0x158/0x420\n xfrm_netlink_rcv+0x71/0x90\n netlink_unicast+0x584/0x850\n netlink_sendmsg+0x8b0/0xdc0\n ____sys_sendmsg+0x9f7/0xb90\n ___sys_sendmsg+0x134/0x1d0\n __sys_sendmsg+0x16d/0x220\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \u003c/TASK\u003e\n\n Allocated by task 9287:\n kasan_save_stack+0x33/0x60\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0xaa/0xb0\n pfkey_add+0x2652/0x2ea0\n pfkey_process+0x6d0/0x830\n pfkey_sendmsg+0x42c/0x850\n __sys_sendto+0x461/0x4b0\n __x64_sys_sendto+0xe0/0x1c0\n do_syscall_64+0x116/0x7d0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n The buggy address belongs to the object at ff11000025a74980\n which belongs to the cache kmalloc-96 of size 96\n The buggy address is located 0 bytes inside of\n allocated 68-byte region [ff11000025a74980, ff11000025a749c4)\n\nDepending on the uninitialized value the same field can instead request\nan oversized kmemdup() allocation and make the migration clone fail.\n\nThe XFRM netlink path is not affected: verify_one_alg() rejects an\nXFRMA_ALG_COMP attribute shorter than xfrm_alg_len(), so a calg added via\nXFRM_MSG_NEWSA is always self-consistent.\n\nInitialize calg-\u003ealg_key_len to 0, matching the aalg/ealg branches."
}
],
"id": "CVE-2026-64436",
"lastModified": "2026-07-27T05:16:50.033",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.2,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-07-25T10:17:28.010",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/01b9115b55018123ef2449ac4951f89147a8428e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/273c06b81d2e902b21acc801ae18c8276c8a9b69"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3f63d1752d90c0e28be931a48ab5d89bc97d637d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/58e82fc3dedb57b1432292504415b224fd2d6acb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6de2a650917bedaaefd65b17cede83c5e2c1dedd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/cea34abc94b0a81e3a8b5cfb41cf45af37c2c67e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d129c3177d7b1138fd5066fcc63a698b3ba415b0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e8417353cbd078d10531ba3928e609c84ab09e6b"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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