{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39894","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.145Z","datePublished":"2025-10-01T07:42:43.126Z","dateUpdated":"2026-05-11T21:38:28.994Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T21:38:28.994Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm\n\nWhen send a broadcast packet to a tap device, which was added to a bridge,\nbr_nf_local_in() is called to confirm the conntrack. If another conntrack\nwith the same hash value is added to the hash table, which can be\ntriggered by a normal packet to a non-bridge device, the below warning\nmay happen.\n\n  ------------[ cut here ]------------\n  WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200\n  CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary)\n  RIP: 0010:br_nf_local_in+0x168/0x200\n  Call Trace:\n   <TASK>\n   nf_hook_slow+0x3e/0xf0\n   br_pass_frame_up+0x103/0x180\n   br_handle_frame_finish+0x2de/0x5b0\n   br_nf_hook_thresh+0xc0/0x120\n   br_nf_pre_routing_finish+0x168/0x3a0\n   br_nf_pre_routing+0x237/0x5e0\n   br_handle_frame+0x1ec/0x3c0\n   __netif_receive_skb_core+0x225/0x1210\n   __netif_receive_skb_one_core+0x37/0xa0\n   netif_receive_skb+0x36/0x160\n   tun_get_user+0xa54/0x10c0\n   tun_chr_write_iter+0x65/0xb0\n   vfs_write+0x305/0x410\n   ksys_write+0x60/0xd0\n   do_syscall_64+0xa4/0x260\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   </TASK>\n  ---[ end trace 0000000000000000 ]---\n\nTo solve the hash conflict, nf_ct_resolve_clash() try to merge the\nconntracks, and update skb->_nfct. However, br_nf_local_in() still use the\nold ct from local variable 'nfct' after confirm(), which leads to this\nwarning.\n\nIf confirm() does not insert the conntrack entry and return NF_DROP, the\nwarning may also occur. There is no need to reserve the WARN_ON_ONCE, just\nremove it."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_netfilter_hooks.c"],"versions":[{"version":"7c3f28599652acf431a2211168de4a583f30b6d5","lessThan":"d00c8b0daf56012f69075e3377da67878c775e4c","status":"affected","versionType":"git"},{"version":"2b1414d5e94e477edff1d2c79030f1d742625ea0","lessThan":"ccbad4803225eafe0175d3cb19f0d8d73b504a94","status":"affected","versionType":"git"},{"version":"80cd0487f630b5382734997c3e5e3003a77db315","lessThan":"50db11e2bbb635e38e3dd096215580d6adb41fb0","status":"affected","versionType":"git"},{"version":"62e7151ae3eb465e0ab52a20c941ff33bb6332e9","lessThan":"c47ca77fee9071aa543bae592dd2a384f895c8b6","status":"affected","versionType":"git"},{"version":"62e7151ae3eb465e0ab52a20c941ff33bb6332e9","lessThan":"a74abcf0f09f59daeecf7a3ba9c1d690808b0afe","status":"affected","versionType":"git"},{"version":"62e7151ae3eb465e0ab52a20c941ff33bb6332e9","lessThan":"479a54ab92087318514c82428a87af2d7af1a576","status":"affected","versionType":"git"},{"version":"cb734975b0ffa688ff6cc0eed463865bf07b6c01","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bridge/br_netfilter_hooks.c"],"versions":[{"version":"6.8","status":"affected"},{"version":"0","lessThan":"6.8","status":"unaffected","versionType":"semver"},{"version":"5.15.192","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.151","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.105","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.46","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.16.6","lessThanOrEqual":"6.16.*","status":"unaffected","versionType":"semver"},{"version":"6.17","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.151","versionEndExcluding":"5.15.192"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.81","versionEndExcluding":"6.1.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.21","versionEndExcluding":"6.6.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.16.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7.9"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d00c8b0daf56012f69075e3377da67878c775e4c"},{"url":"https://git.kernel.org/stable/c/ccbad4803225eafe0175d3cb19f0d8d73b504a94"},{"url":"https://git.kernel.org/stable/c/50db11e2bbb635e38e3dd096215580d6adb41fb0"},{"url":"https://git.kernel.org/stable/c/c47ca77fee9071aa543bae592dd2a384f895c8b6"},{"url":"https://git.kernel.org/stable/c/a74abcf0f09f59daeecf7a3ba9c1d690808b0afe"},{"url":"https://git.kernel.org/stable/c/479a54ab92087318514c82428a87af2d7af1a576"}],"title":"netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"}],"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2025-11-03T17:44:28.733Z"}}]}}