CVE-2021-46913

netfilter: nftables: clone set element expression template

MEDIUM
5.5
CVSS Score
Published: February 27, 2024 at 06:53 AM UTC
Updated: August 5, 2026 at 09:24 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nftables: clone set element expression template memcpy() breaks when using connlimit in set elements. Use nft_expr_clone() to initialize the connlimit expression list, otherwise connlimit garbage collector crashes when walking on the list head copy. [ 493.064656] Workqueue: events_power_efficient nft_rhash_gc [nf_tables] [ 493.064685] RIP: 0010:find_or_evict+0x5a/0x90 [nf_conncount] [ 493.064694] Code: 2b 43 40 83 f8 01 77 0d 48 c7 c0 f5 ff ff ff 44 39 63 3c 75 df 83 6d 18 01 48 8b 43 08 48 89 de 48 8b 13 48 8b 3d ee 2f 00 00 <48> 89 42 08 48 89 10 48 b8 00 01 00 00 00 00 ad de 48 89 03 48 83 [ 493.064699] RSP: 0018:ffffc90000417dc0 EFLAGS: 00010297 [ 493.064704] RAX: 0000000000000000 RBX: ffff888134f38410 RCX: 0000000000000000 [ 493.064708] RDX: 0000000000000000 RSI: ffff888134f38410 RDI: ffff888100060cc0 [ 493.064711] RBP: ffff88812ce594a8 R08: ffff888134f38438 R09: 00000000ebb9025c [ 493.064714] R10: ffffffff8219f838 R11: 0000000000000017 R12: 0000000000000001 [ 493.064718] R13: ffffffff82146740 R14: ffff888134f38410 R15: 0000000000000000 [ 493.064721] FS: 0000000000000000(0000) GS:ffff88840e440000(0000) knlGS:0000000000000000 [ 493.064725] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 493.064729] CR2: 0000000000000008 CR3: 00000001330aa002 CR4: 00000000001706e0 [ 493.064733] Call Trace: [ 493.064737] nf_conncount_gc_list+0x8f/0x150 [nf_conncount] [ 493.064746] nft_rhash_gc+0x106/0x390 [nf_tables]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11.0 ≤ v < 5.11.165.7 ≤ v < 5.10.645.7 ≤ v < 5.11.165.7 ≤ v < 5.125.7.0 ≤ v < 5.10.644094445229760d0d31a4190dfe88fe815c9fc34e5.7
Vendor states this is fixed in 47d8de3c226574a3ddb8b87d0c152028d1bafef4 (fixed)
Vendor states this is fixed in 4d8f9065830e526c83199186c5f56a6514f457d2 (fixed)
Vendor states this is fixed in e51ff3ffc316377cca21de8b80404eed0c37b3c3 (fixed)
Vendor states this is fixed in 5.10.64 (unaffected)
Vendor states this is fixed in 5.11.16 (unaffected)
Vendor states this is fixed in 5.12 (unaffected)
Vendor states this is fixed in 5.7 (unaffected)

References (3)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/47d8de3c226574a3ddb8b87d0c152028d1bafef4
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/4d8f9065830e526c83199186c5f56a6514f457d2
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/e51ff3ffc316377cca21de8b80404eed0c37b3c3

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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