netfilter: ebt_nflog: pin the NFLOG backend
In the Linux kernel, the following vulnerability has been resolved: netfilter: ebt_nflog: pin the NFLOG backend nf_log_unregister() runs after the per-net teardown so its final RCU grace period also drains readers that obtained the logger from a per-net binding. However, ebt_nflog passes an explicit ULOG log type to nf_log_packet() without holding a reference on the selected logger module, unlike the xt_NFLOG and nft_log frontends. An ebtables nflog rule can therefore remain callable while nfnetlink_log is unloaded. The resulting interleaving is: CPU 0 CPU 1 nfnetlink_log_fini() unregister_pernet_subsys() kfree(nfnl_log_pernet(net)) ebt_nflog_tg() nf_log_packet() nfulnl_log_packet() instance_lookup_get_rcu() The global ULOG logger is still registered at this point, so CPU 1 dereferences the per-net state after CPU 0 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu Read of size 8 at addr ff110001052e6210 by task poc/92 Call Trace: instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log] nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log] nf_log_packet+0x204/0x300 ebt_nflog_tg+0x351/0x550 ebt_do_table+0xedf/0x22b0 Allocated by task 90: __kmalloc_noprof+0x186/0x470 ops_init+0x6d/0x420 register_pernet_operations+0x2f6/0x670 register_pernet_subsys+0x23/0x40 Freed by task 93: kfree+0x131/0x3c0 ops_undo_list+0x3e3/0x700 unregister_pernet_operations+0x232/0x490 unregister_pernet_subsys+0x1c/0x30 nfnetlink_log_fini+0x34/0x450 [nfnetlink_log] Acquire the U
CVE-2026-74660
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-74660
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "3bcce49d617c593c7606083bfdb464a1761fa68d",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "394d7939c6b2b9e6bea0844c89efb5913168d898",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "2cac4294f184c9bc19ff82552c62b80498694c39",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "9d8a94b48b393885e7f876c8ef68ed4da5012078",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "6809379a860b9fccbb5435bf08343f6d081ac68d",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "e2ab7e878bdbe80104c879c31fd2d82a476703b8",
"versionType": "git"
},
{
"status": "affected",
"version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee",
"lessThan": "30825970339c107bacaf7f61af90fcdb1f597ca1",
"versionType": "git"
}
],
"programFiles": [
"net/bridge/netfilter/ebt_nflog.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.152",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bridge/netfilter/ebt_nflog.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74660
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #34261 · Revision 1
- Added to Heist Feed
- Publisher date