NetSight
IP …
high7.8

CVE-2024-41042

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: prefer nft_chain_validate nft_chain_validate already performs loop de…

Impact

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: prefer nft_chain_validate nft_chain_validate already performs loop detection because a cycle will result in a call stack overflow (ctx->level >= NFT_JUMP_STACK_SIZE). It also follows maps via ->validate callback in nft_lookup, so there appears no reason to iterate the maps again. nf_tables_check_loops() and all its helper functions can be removed. This improves ruleset load time significantly, from 23s down to 12s. This also fixes a crash bug. Old loop detection code can result in unbounded recursion: BUG: TASK stack guard page was hit at .... Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN CPU: 4 PID: 1539 Comm: nft Not tainted 6.10.0-rc5+ #1 [..] with a suitable ruleset during validation of register stores. I can't see any actual reason to attempt to check for this from nft_validate_register_store(), at this point the transaction is still in progress, so we don't have a full picture of the rule graph. For nf-next it might make sense to either remove it or make this depend on table->validate_state in case we could catch an error earlier (for improved error reporting to userspace).

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 3.13 before 4.19.320
from 4.20 before 5.4.282
from 5.5 before 5.10.224
from 5.11 before 5.15.165
from 5.16 before 6.1.105
from 6.2 before 6.6.46

Weakness classification

CWE-787

References