netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 5.15.192, 6.1.151, 6.6.105, 6.8, 6.12.46, and 1 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm When send a broadcast packet to a tap device, which was added to a bridge, br_nf_local_in() is called to confirm the conntrack. If another conntrack with the same hash value is added to the hash table, which can be triggered by a normal packet to a non-bridge device, the below warning may happen. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200 CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary) RIP: 0010:br_nf_local_in+0x168/0x200 Call Trace: <TASK> nf_hook_slow+0x3e/0xf0 br_pass_frame_up+0x103/0x180 br_handle_frame_finish+0x2de/0x5b0 br_nf_hook_thresh+0xc0/0x120 br_nf_pre_routing_finish+0x168/0x3a0 br_nf_pre_routing+0x237/0x5e0 br_handle_frame+0x1ec/0x3c0 __netif_receive_skb_core+0x225/0x1210 __netif_receive_skb_one_core+0x37/0xa0 netif_receive_skb+0x36/0x160 tun_get_user+0xa54/0x10c0 tun_chr_write_iter+0x65/0xb0 vfs_write+0x305/0x410 ksys_write+0x60/0xd0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> ---[ end trace 0000000000000000 ]--- To solve the hash conflict, nf_ct_resolve_clash() try to merge the conntracks, and update skb->_nfct. However, br_nf_local_in() still use the old ct from local variable 'nfct' after confirm(), which leads to this warning. If confirm() does not insert the conntrack entry and return NF_DROP, the warning may also occur. There is no need to reserve the WARN_ON_ONCE, just remove it.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- Linux Linux
From 7c3f28599652acf431a2211168de4a583f30b6d5 · fixed in d00c8b0daf56012f69075e3377da67878c775e4c; From 2b1414d5e94e477edff1d2c79030f1d742625ea0 · fixed in ccbad4803225eafe0175d3cb19f0d8d73b504a94; From 80cd0487f630b5382734997c3e5e3003a77db315 · fixed in 50db11e2bbb635e38e3dd096215580d6adb41fb0; From 62e7151ae3eb465e0ab52a20c941ff33bb6332e9 · fixed in c47ca77fee9071aa543bae592dd2a384f895c8b6; From 62e7151ae3eb465e0ab52a20c941ff33bb6332e9 · fixed in a74abcf0f09f59daeecf7a3ba9c1d690808b0afe; From 62e7151ae3eb465e0ab52a20c941ff33bb6332e9 · fixed in 479a54ab92087318514c82428a87af2d7af1a576; From 5.15.151 · fixed in 5.15.192; From 6.1.81 · fixed in 6.1.151; From 6.6.21 · fixed in 6.6.105; From 6.7.9 · fixed in 6.8
- Linux Linux
6.8
- KernelLinux
fixed in 5.15.192; From 5.16.0 · fixed in 6.1.151; From 6.2.0 · fixed in 6.6.105; From 6.7.0 · fixed in 6.12.46; From 6.8.0 · fixed in 6.16.6