In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_fib: fix stale stack leak via the OIFNAME register For NFT_FIB_RESULT_OIFNAME the destination register is declared with len = IFNAMSIZ (four 32-bit registers), but on the lookup-fail, RTN_LOCAL and oif-mismatch paths nft_fib{4,6}_eval() only writes one register via "*dest = 0". The remaining three registers are left as whatever was on the stack in nft_do_chain()'s struct nft_regs, and a downstream expression that loads the register span can leak that uninitialised kernel stack to userspace. The NFTA_FIB_F_PRESENT existence check has the same shape: it is only meaningful for NFT_FIB_RESULT_OIF, yet it was accepted for any result type while the eval stores a single byte via nft_reg_store8(), leaving the rest of the declared span stale. Fix both: - replace the bare "*dest = 0" in the eval with nft_fib_store_result(), which strscpy_pad()s the whole IFNAMSIZ for OIFNAME (and is already used on the other early-return path), and - restrict NFTA_FIB_F_PRESENT to NFT_FIB_RESULT_OIF and declare its destination as a single u8, so the marked span matches the one byte the eval writes.
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
CWE-401
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d24244f7900> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23a5905780> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23beb86580> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23bea8be00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23a59c2d40> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23a59c3b40> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7d23beb1d000> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23beb840c0> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23beb86e80> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23a59c1d00> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23beb87000> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23af256180> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23a59e0780> | Operating System |
| linux | linux_kernel | 7.1 | <built-in method update of dict object at 0x7d23a5907640> | 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:7.1:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* |