CVE-2024-50256

CVE Details

Release Date:

2024-11-09

Description

In the Linux kernel, the following vulnerability has been resolved:\nnetfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()\nI got a syzbot report without a repro [1] crashing in nf_send_reset6()\nI think the issue is that dev->hard_header_len is zero, and we attempt\nlater to push an Ethernet header.\nUse LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.\n[1]\nskbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun\nkernel BUG at net/core/skbuff.c:206 !\nOops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI\nCPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024\nRIP: 0010:skb_panic net/core/skbuff.c:206 [inline]\nRIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216\nCode: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3\nRSP: 0018:ffffc900045269b0 EFLAGS: 00010282\nRAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800\nRDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000\nRBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc\nR10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140\nR13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c\nFS: 00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n\nskb_push+0xe5/0x100 net/core/skbuff.c:2636\neth_header+0x38/0x1f0 net/ethernet/eth.c:83\ndev_hard_header include/linux/netdevice.h:3208 [inline]\nnf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358\nnft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48\nexpr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]\nnft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288\nnft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161\nnf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\nnf_hook_slow+0xc3/0x220 net/netfilter/core.c:626\nnf_hook include/linux/netfilter.h:269 [inline]\nNF_HOOK include/linux/netfilter.h:312 [inline]\nbr_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184\nnf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]\nnf_hook_bridge_pre net/bridge/br_input.c:277 [inline]\nbr_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424\n__netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562\n__netif_receive_skb_one_core net/core/dev.c:5666 [inline]\n__netif_receive_skb+0x12f/0x650 net/core/dev.c:5781\nnetif_receive_skb_internal net/core/dev.c:5867 [inline]\nnetif_receive_skb+0x1e8/0x890 net/core/dev.c:5926\ntun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550\ntun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007\ntun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053\nnew_sync_write fs/read_write.c:590 [inline]\nvfs_write+0xa6d/0xc90 fs/read_write.c:683\nksys_write+0x183/0x2b0 fs/read_write.c:736\ndo_syscall_x64 arch/x86/entry/common.c:52 [inline]\ndo_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83\nentry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7fdbeeb7d1ff\nCode: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48\nRSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001\nRAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff\nRDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8\nRBP: 00007fdbeebf12be R08: 0000000\n---truncated---

See more information about CVE-2024-50256 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	5.5
Vector String:	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Local
Attack Complexity:	Low
Privileges Required:	Low
User Interaction:	None
Scope:	Unchanged
Confidentiality:	None
Integrity:	None
Availability:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (kernel)	ELSA-2024-10943	2024-12-11