CWE
908
Advisory Published
Updated

CVE-2024-47685: netfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put()

First published: Mon Oct 21 2024(Updated: )

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put() syzbot reported that nf_reject_ip6_tcphdr_put() was possibly sending garbage on the four reserved tcp bits (th->res1) Use skb_put_zero() to clear the whole TCP header, as done in nf_reject_ip_tcphdr_put() BUG: KMSAN: uninit-value in nf_reject_ip6_tcphdr_put+0x688/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:255 nf_reject_ip6_tcphdr_put+0x688/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:255 nf_send_reset6+0xd84/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:344 nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5661 [inline] __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5775 process_backlog+0x4ad/0xa50 net/core/dev.c:6108 __napi_poll+0xe7/0x980 net/core/dev.c:6772 napi_poll net/core/dev.c:6841 [inline] net_rx_action+0xa5a/0x19b0 net/core/dev.c:6963 handle_softirqs+0x1ce/0x800 kernel/softirq.c:554 __do_softirq+0x14/0x1a kernel/softirq.c:588 do_softirq+0x9a/0x100 kernel/softirq.c:455 __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:382 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:908 [inline] __dev_queue_xmit+0x2692/0x5610 net/core/dev.c:4450 dev_queue_xmit include/linux/netdevice.h:3105 [inline] neigh_resolve_output+0x9ca/0xae0 net/core/neighbour.c:1565 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x2347/0x2ba0 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0xbb8/0x14b0 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x356/0x620 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip6_xmit+0x1ba6/0x25d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x442/0x530 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x3b07/0x4880 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_connect+0x35b6/0x7130 net/ipv4/tcp_output.c:4143 tcp_v6_connect+0x1bcc/0x1e40 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x2ef/0x1730 net/ipv4/af_inet.c:679 inet_stream_connect+0x6a/0xd0 net/ipv4/af_inet.c:750 __sys_connect_file net/socket.c:2061 [inline] __sys_connect+0x606/0x690 net/socket.c:2078 __do_sys_connect net/socket.c:2088 [inline] __se_sys_connect net/socket.c:2085 [inline] __x64_sys_connect+0x91/0xe0 net/socket.c:2085 x64_sys_call+0x27a5/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:43 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: nf_reject_ip6_tcphdr_put+0x60c/0x6c0 net/ipv6/netfilter/nf_reject_ipv6.c:249 nf_send_reset6+0xd84/0x15b0 net/ipv6/netfilter/nf_reject_ipv6.c:344 nft_reject_inet_eval+0x3c1/0x880 net/netfilter/nft_reject_inet.c:48 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x438/0x22a0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x41a/0x4f0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ipv6_rcv+0x29b/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core ---truncated---

Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Affected SoftwareAffected VersionHow to fix
Linux Kernel>=3.18<5.10.227
Linux Kernel>=5.11<5.15.168
Linux Kernel>=5.16<6.1.113
Linux Kernel>=6.2<6.6.54
Linux Kernel>=6.7<6.10.13
Linux Kernel>=6.11<6.11.2
debian/linux<=5.10.223-1<=5.10.226-1
6.1.123-1
6.1.128-1
6.12.12-1
6.12.15-1
debian/linux-6.1
6.1.119-1~deb11u1

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Frequently Asked Questions

  • What is the severity of CVE-2024-47685?

    CVE-2024-47685 is considered to have a medium severity level due to its impact on the functionality of TCP header processing.

  • How do I fix CVE-2024-47685?

    To fix CVE-2024-47685, upgrade your Linux kernel to a version that includes the relevant patches, such as 6.1.123-1 or later.

  • Which Linux kernel versions are affected by CVE-2024-47685?

    CVE-2024-47685 affects Linux kernel versions between 3.18 and 5.10.227, as well as several versions in the 5.11 to 6.11 range.

  • What is the nature of the vulnerability in CVE-2024-47685?

    The vulnerability in CVE-2024-47685 involves nf_reject_ip6_tcphdr_put() potentially sending incorrect values on reserved TCP bits.

  • Who reported the CVE-2024-47685 vulnerability?

    The CVE-2024-47685 vulnerability was reported by the syzbot automated testing system.

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