UBUNTU-CVE-2024-42109
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.
02 / AFFECTED SOFTWARE
Affected packages
12 explicit affected versions
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37 explicit affected versions
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12 explicit affected versions
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10 explicit affected versions
6 explicit affected versions
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51 explicit affected versions
7 explicit affected versions
50 explicit affected versions
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35 explicit affected versions
11 explicit affected versions
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12 explicit affected versions
37 explicit affected versions
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12 explicit affected versions
14 explicit affected versions
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11 explicit affected versions
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1 explicit affected versions
26 explicit affected versions
13 explicit affected versions
6 explicit affected versions
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6 explicit affected versions
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23 explicit affected versions
10 explicit affected versions
1 explicit affected versions
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42 explicit affected versions
36 explicit affected versions
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10 explicit affected versions
26 explicit affected versions
14 explicit affected versions
1 explicit affected versions
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15 explicit affected versions
13 explicit affected versions
14 explicit affected versions
16 explicit affected versions
55 explicit affected versions
15 explicit affected versions
43 explicit affected versions
3 explicit affected versions
2 explicit affected versions
51 explicit affected versions
12 explicit affected versions
8 explicit affected versions
12 explicit affected versions
41 explicit affected versions
27 explicit affected versions
27 explicit affected versions
13 explicit affected versions
16 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
7 explicit affected versions
46 explicit affected versions
10 explicit affected versions
13 explicit affected versions
12 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
41 explicit affected versions
37 explicit affected versions
15 explicit affected versions
14 explicit affected versions
38 explicit affected versions
44 explicit affected versions
9 explicit affected versions
44 explicit affected versions
11 explicit affected versions
52 explicit affected versions
7 explicit affected versions
25 explicit affected versions
4 explicit affected versions
1 explicit affected versions
50 explicit affected versions
13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
11 explicit affected versions
1 explicit affected versions
8 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/9f6958ba2e902f9820c594869bd710ba74b7c4c0
- https://git.kernel.org/stable/c/09e650c3a3a7d804430260510534ccbf71c75b2e
- https://git.kernel.org/stable/c/3325628cb36b7f216c5716e7b5124d9dc81199e4
- https://git.kernel.org/stable/c/4c06c13317b9a08decedcd7aaf706691e336277c
- https://git.kernel.org/stable/c/55a40406aac555defe9bdd0adec9508116ce7cb1
- https://git.kernel.org/stable/c/9f6958ba2e902f9820c594869bd710ba74b7c4c0
- https://ubuntu.com/security/CVE-2024-42109
- https://ubuntu.com/security/notices/USN-7007-1
- https://ubuntu.com/security/notices/USN-7007-2
- https://ubuntu.com/security/notices/USN-7007-3
- https://ubuntu.com/security/notices/USN-7009-1
- https://ubuntu.com/security/notices/USN-7009-2
- https://ubuntu.com/security/notices/USN-7019-1
- https://ubuntu.com/security/notices/USN-7089-1
- https://ubuntu.com/security/notices/USN-7089-2
- https://ubuntu.com/security/notices/USN-7089-3
- https://ubuntu.com/security/notices/USN-7089-4
- https://ubuntu.com/security/notices/USN-7089-5
- https://ubuntu.com/security/notices/USN-7089-6
- https://ubuntu.com/security/notices/USN-7089-7
- https://ubuntu.com/security/notices/USN-7090-1
- https://ubuntu.com/security/notices/USN-7095-1
- https://ubuntu.com/security/notices/USN-7156-1
- https://www.cve.org/CVERecord?id=CVE-2024-42109