CVE-2024-42109: netfilter: nf_tables: unconditionally flush pending work before notifier
Vulnerability summary
CVE-2024-42109 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.3% of scored vulnerabilities.
Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 24 · Related 21Timeline
- 30-07-2024PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: unconditionally flush pending work before notifier syzbot reports: KASAN: slab-uaf in nft_ctx_update include/net/netfilter/nf_tables.h:1831 KASAN: slab-uaf in nft_commit_release net/netfilter/nf_tables_api.c:9530 KASAN: slab-uaf int nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597 Read of size 2 at addr ffff88802b0051c4 by task kworker/1:1/45 [..] Workqueue: events nf_tables_trans_destroy_work Call Trace: nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline] nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline] nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597 Problem is that the notifier does a conditional flush, but its possible that the table-to-be-removed is still referenced by transactions being processed by the worker, so we need to flush unconditionally. We could make the flush_work depend on whether we found a table to delete in nf-next to avoid the flush for most cases. AFAICS this problem is only exposed in nf-next, with commit e169285f8c56 ("netfilter: nf_tables: do not store nft_ctx in transaction objects"), with this commit applied there is an unconditional fetch of table->family which is whats triggering the above splat.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.25% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu117 products
- linux< 5.15.0-121.131 | < 6.8.0-48.48
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1069.75 | < 6.8.0-1018.20
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ f22954f8c58fd5f5489f5980796914e306757e77, < 3325628cb36b7f216c5716e7b5124d9dc81199e4 | ≥ 41841b585e53babdfb0fa6fdfa54f6d7c28c1206, < 4c06c13317b9a08decedcd7aaf706691e336277c | ≥ 2c9f0293280e258606e54ed2b96fa71498432eae, < 55a40406aac555defe9bdd0adec9508116ce7cb1 | ≥ 2c9f0293280e258606e54ed2b96fa71498432eae, < 09e650c3a3a7d804430260510534ccbf71c75b2e | ≥ 2c9f0293280e258606e54ed2b96fa71498432eae, < 9f6958ba2e902f9820c594869bd710ba74b7c4c0 | 4167aa477abcf62b0dfda51f3513280fa73cd588 | ≥ 5.15.129, < 5.15.163 | ≥ 6.1.50, < 6.1.98 | ≥ 6.4.13, < 6.5 | 6.5
- linux_kernel≥ 5.15.129, < 5.15.163 | ≥ 6.1.50, < 6.1.98 | ≥ 6.5, < 6.6.39 | ≥ 6.7, < 6.9.9
Debian1 product
- linux< 6.1.98-1 | < 6.9.9-1
3 vendors · 120 products
