4.2 KiB
CVE-2024-27018
Description
In the Linux kernel, the following vulnerability has been resolved:netfilter: br_netfilter: skip conntrack input hook for promisc packetsFor historical reasons, when bridge device is in promisc mode, packetsthat are directed to the taps follow bridge input hook path. This patchadds a workaround to reset conntrack for these packets.Jianbo Liu reports warning splats in their test infrastructure wherecloned packets reach the br_netfilter input hook to confirm theconntrack object.Scratch one bit from BR_INPUT_SKB_CB to annotate that this packet hasreached the input hook because it is passed up to the bridge device toreach the taps.[ 57.571874] WARNING: CPU: 1 PID: 0 at net/bridge/br_netfilter_hooks.c:616 br_nf_local_in+0x157/0x180 [br_netfilter][ 57.572749] Modules linked in: xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype xt_conntrack nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_isc si ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_ib ib_uverbs ib_core mlx5ctl mlx5_core[ 57.575158] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0+ #19[ 57.575700] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014[ 57.576662] RIP: 0010:br_nf_local_in+0x157/0x180 [br_netfilter][ 57.577195] Code: fe ff ff 41 bd 04 00 00 00 be 04 00 00 00 e9 4a ff ff ff be 04 00 00 00 48 89 ef e8 f3 a9 3c e1 66 83 ad b4 00 00 00 04 eb 91 <0f> 0b e9 f1 fe ff ff 0f 0b e9 df fe ff ff 48 89 df e8 b3 53 47 e1[ 57.578722] RSP: 0018:ffff88885f845a08 EFLAGS: 00010202[ 57.579207] RAX: 0000000000000002 RBX: ffff88812dfe8000 RCX: 0000000000000000[ 57.579830] RDX: ffff88885f845a60 RSI: ffff8881022dc300 RDI: 0000000000000000[ 57.580454] RBP: ffff88885f845a60 R08: 0000000000000001 R09: 0000000000000003[ 57.581076] R10: 00000000ffff1300 R11: 0000000000000002 R12: 0000000000000000[ 57.581695] R13: ffff8881047ffe00 R14: ffff888108dbee00 R15: ffff88814519b800[ 57.582313] FS: 0000000000000000(0000) GS:ffff88885f840000(0000) knlGS:0000000000000000[ 57.583040] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033[ 57.583564] CR2: 000000c4206aa000 CR3: 0000000103847001 CR4: 0000000000370eb0[ 57.584194] DR0: 0000000000000000 DR1: 0000000000000000 DR2:0000000000000000[ 57.584820] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:0000000000000400[ 57.585440] Call Trace:[ 57.585721] [ 57.585976] ? __warn+0x7d/0x130[ 57.586323] ? br_nf_local_in+0x157/0x180 [br_netfilter][ 57.586811] ? report_bug+0xf1/0x1c0[ 57.587177] ? handle_bug+0x3f/0x70[ 57.587539] ? exc_invalid_op+0x13/0x60[ 57.587929] ? asm_exc_invalid_op+0x16/0x20[ 57.588336] ? br_nf_local_in+0x157/0x180 [br_netfilter][ 57.588825] nf_hook_slow+0x3d/0xd0[ 57.589188] ? br_handle_vlan+0x4b/0x110[ 57.589579] br_pass_frame_up+0xfc/0x150[ 57.589970] ? br_port_flags_change+0x40/0x40[ 57.590396] br_handle_frame_finish+0x346/0x5e0[ 57.590837] ? ipt_do_table+0x32e/0x430[ 57.591221] ? br_handle_local_finish+0x20/0x20[ 57.591656] br_nf_hook_thresh+0x4b/0xf0 [br_netfilter][ 57.592286] ? br_handle_local_finish+0x20/0x20[ 57.592802] br_nf_pre_routing_finish+0x178/0x480 [br_netfilter][ 57.593348] ? br_handle_local_finish+0x20/0x20[ 57.593782] ? nf_nat_ipv4_pre_routing+0x25/0x60 [nf_nat][ 57.594279] br_nf_pre_routing+0x24c/0x550 [br_netfilter][ 57.594780] ? br_nf_hook_thresh+0xf0/0xf0 [br_netfilter][ 57.595280] br_handle_frame+0x1f3/0x3d0[ 57.595676] ? br_handle_local_finish+0x20/0x20[ 57.596118] ? br_handle_frame_finish+0x5e0/0x5e0[ 57.596566] __netif_receive_skb_core+0x25b/0xfc0[ 57.597017] ? __napi_build_skb+0x37/0x40[ 57.597418] __netif_receive_skb_list_core+0xfb/0x220
POC
Reference
No PoCs from references.