In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absent ctnetlink_alloc_expect() allocates expectations from a non-zeroing slab cache via nf_ct_expect_alloc(). When CTA_EXPECT_NAT is not present in the netlink message, saved_addr and saved_proto are never initialized. Stale data from a previous slab occupant can then be dumped to userspace by ctnetlink_exp_dump_expect(), which checks these fields to decide whether to emit CTA_EXPECT_NAT. The safe sibling nf_ct_expect_init(), used by the packet path, explicitly zeroes these fields. Zero saved_addr, saved_proto and dir in the else branch, guarded by IS_ENABLED(CONFIG_NF_NAT) since these fields only exist when NAT is enabled. Confirmed by priming the expect slab with NAT-bearing expectations, freeing them, creating a new expectation without CTA_EXPECT_NAT, and observing that the ctnetlink dump emits a spurious CTA_EXPECT_NAT containing stale data from the prior allocation.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
NVD-CWE-noinfo
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| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23a59841c0> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245af940> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea7a340> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea79b00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24245bb540> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea7a780> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23a5986e80> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d242455fc40> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d24245372c0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d23a7f74fc0> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d25cf20c280> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2424534d80> | Operating System |
| linux | linux_kernel | 7.0 | <built-in method update of dict object at 0x7d2424536a80> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* |