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Fencer Vulns
high 7.5

CVE-2024-50256 json

netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()

published 2024-11-09 1 y ago modified 2026-08-05 3 mo ago also EUVD-2024-44758

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()

I got a syzbot report without a repro [1] crashing in nf_send_reset6()

I think the issue is that dev->hard_header_len is zero, and we attempt later to push an Ethernet header.

Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.

[1]

skbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun kernel BUG at net/core/skbuff.c:206 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline] RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216 Code: 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 RSP: 0018:ffffc900045269b0 EFLAGS: 00010282 RAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800 RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000 RBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc R10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140 R13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c FS: 00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> skb_push+0xe5/0x100 net/core/skbuff.c:2636 eth_header+0x38/0x1f0 net/ethernet/eth.c:83 dev_hard_header include/linux/netdevice.h:3208 [inline] nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358 nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5781 netif_receive_skb_internal net/core/dev.c:5867 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926 tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550 tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007 tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xa6d/0xc90 fs/read_write.c:683 ksys_write+0x183/0x2b0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdbeeb7d1ff Code: 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 RSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff RDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8 RBP: 00007fdbeebf12be R08: 0000000 ---truncated---

Patch / fix

  • Linux Linux 6.1.116, 6.6.60, 6.11.7, 6.12
  • linux Debian 12 6.1.119-1
  • linux Debian 14, Debian 13 6.11.7-1

debian advisories DEBIAN-CVE-2024-50256

  • linux Ubuntu 20.04 LTS 5.4.0-214.234
  • linux Ubuntu 22.04 LTS 5.15.0-138.148
  • linux Ubuntu 24.04 LTS 6.8.0-58.60
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1144.154
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1082.89
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1027.29
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1147.156
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1081.90

ubuntu advisories UBUNTU-CVE-2024-50256

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-570.12.1.el9_6
  • rv RHEL 9 5.14.0-570.12.1.el9_6
  • perf RHEL 9 5.14.0-570.12.1.el9_6
  • rtla RHEL 9 5.14.0-570.12.1.el9_6
  • libperf RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-rt RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-64k RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-core RHEL 9 5.14.0-570.12.1.el9_6

red hat advisories RHSA-2025:6966RHSA-2025:1658RHSA-2024:10943RHSA-2024:10944

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-livepatch-MICRO-6-0-RT_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1.21.4
  • kernel-livepatch-MICRO-6-0_Update_5 Linux Micro 6.1, Linux Micro 6.0 1-1.2

suse advisories SUSE-SU-2025:20166-1SUSE-SU-2025:20249-1SUSE-SU-2025:20165-1SUSE-SU-2025:20248-1SUSE-SU-2025:0201-1SUSE-SU-2025:0201-2

  • kernel-source-longterm openSUSE Tumbleweed 6.12.11-1.1
  • kernel-source openSUSE Tumbleweed 6.11.8-1.1

opensuse advisories openSUSE-SU-2025:14705-1openSUSE-SU-2024:14500-1

  • kernel AlmaLinux 8 4.18.0-553.32.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.32.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.32.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.32.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.32.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.32.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.32.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.32.1.el8_10

almalinux advisories ALSA-2024:10943ALSA-2024:10944

  • kernel-rt Rocky Linux 8 4.18.0-553.32.1.rt7.373.el8_10
  • kernel Rocky Linux 8 4.18.0-553.32.1.el8_10

rocky linux advisories RLSA-2024:10944RLSA-2024:10943

  • kernel Azure Linux 3.0 6.6.64.2-1

azure linux advisories AZL-53313

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-50256 updated cvss 5.5

kernel: netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.55.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.55.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.55.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.55.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.55.1.el9_4
    fixed: vendor fix RHSA-2025:1658
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.12.1.el9_6, perf 5.14.0-570.12.1.el9_6, rtla 5.14.0-570.12.1.el9_6, python3-perf 5.14.0-570.12.1.el9_6, kernel-devel-matched 5.14.0-570.12.1.el9_6, kernel-64k-devel-matched 5.14.0-570.12.1.el9_6, +7 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.55.1.el9_4, perf 5.14.0-427.55.1.el9_4, rtla 5.14.0-427.55.1.el9_4, kernel-devel-matched 5.14.0-427.55.1.el9_4, kernel-64k-devel-matched 5.14.0-427.55.1.el9_4, kernel-debug-devel-matched 5.14.0-427.55.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:1658
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.32.1.el8_10, kernel 4.18.0-553.32.1.el8_10, bpftool 4.18.0-553.32.1.el8_10, kernel-core 4.18.0-553.32.1.el8_10, kernel-tools 4.18.0-553.32.1.el8_10, python3-perf 4.18.0-553.32.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:10943
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.12.1.el9_6, kernel-64k 5.14.0-570.12.1.el9_6, kernel-core 5.14.0-570.12.1.el9_6, kernel-tools 5.14.0-570.12.1.el9_6, kernel-modules 5.14.0-570.12.1.el9_6, kernel-64k-core 5.14.0-570.12.1.el9_6, +27 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.55.1.el9_4, kernel 5.14.0-427.55.1.el9_4, kernel-64k 5.14.0-427.55.1.el9_4, kernel-core 5.14.0-427.55.1.el9_4, kernel-tools 5.14.0-427.55.1.el9_4, python3-perf 5.14.0-427.55.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:1658
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.12.1.el9_6
    fixed: vendor fix RHSA-2025:6966
show 8 more
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.32.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.32.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.32.1.el8_10
    fixed: vendor fix RHSA-2024:10943
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-kvm 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-core 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-modules 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-debug-kvm 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-debug-core 4.18.0-553.32.1.rt7.373.el8_10, +4 more
    fixed: vendor fix RHSA-2024:10944
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-64k 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-64k-core 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +14 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.55.1.el9_4, kernel-rt-core 5.14.0-427.55.1.el9_4, kernel-rt-modules 5.14.0-427.55.1.el9_4, kernel-rt-debug-core 5.14.0-427.55.1.el9_4, kernel-rt-modules-core 5.14.0-427.55.1.el9_4, kernel-rt-debug-modules 5.14.0-427.55.1.el9_4, +4 more
    fixed: vendor fix RHSA-2025:1658
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-kvm 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +6 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.55.1.el9_4, kernel-rt-kvm 5.14.0-427.55.1.el9_4, kernel-rt-core 5.14.0-427.55.1.el9_4, kernel-rt-modules 5.14.0-427.55.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.55.1.el9_4, kernel-rt-debug-core 5.14.0-427.55.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:1658
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-core 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-modules 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-debug-core 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-debug-modules 4.18.0-553.32.1.rt7.373.el8_10, kernel-rt-modules-extra 4.18.0-553.32.1.rt7.373.el8_10, +2 more
    fixed: vendor fix RHSA-2024:10944
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.