How severe is CVE-2024-47684?

CVE-2024-47684 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2024-47684 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-47684?

CVE-2024-47684 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-47684?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2024-47684 have an EU (EUVD) identifier?

Yes. CVE-2024-47684 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-42604.

When was CVE-2024-47684 published?

CVE-2024-47684 was published on 2024-10-21 and last updated on 2026-06-17.

CVE-2024-47684

CVE-2024-47684 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-42604
Weakness: CWE-476
Affected product: Linux Linux Kernel
Published: 2024-10-21
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: check skb is non-NULL in tcp_rto_delta_us() We have some machines running stock Ubuntu 20.04.6 which is their 5.4.0-174-generic kernel that are running ceph and recently hit a null ptr dereference in tcp_rearm_rto(). Initially hitting it from the TLP path, but then later we also saw it getting hit from the RACK case as well. Here are examples of the oops messages we saw in each of those cases: Jul 26 15:05:02 rx [11061395.780353] BUG: kernel NULL pointer dereference, address: 0000000000000020 Jul 26 15:05:02 rx [11061395.787572] #PF: supervisor read access in kernel mode Jul 26 15:05:02 rx [11061395.792971] #PF: error_code(0x0000) - not-present page Jul 26 15:05:02 rx [11061395.798362] PGD 0 P4D 0 Jul 26 15:05:02 rx [11061395.801164] Oops: 0000 [#1] SMP NOPTI Jul 26 15:05:02 rx [11061395.805091] CPU: 0 PID: 9180 Comm: msgr-worker-1 Tainted: G W 5.4.0-174-generic #193-Ubuntu Jul 26 15:05:02 rx [11061395.814996] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023 Jul 26 15:05:02 rx [11061395.825952] RIP: 0010:tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.830656] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3 Jul 26 15:05:02 rx [11061395.849665] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246 Jul 26 15:05:02 rx [11061395.855149] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000 Jul 26 15:05:02 rx [11061395.862542] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60 Jul 26 15:05:02 rx [11061395.869933] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8 Jul 26 15:05:02 rx [11061395.877318] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900 Jul 26 15:05:02 rx [11061395.884710] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30 Jul 26 15:05:02 rx [11061395.892095] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000 Jul 26 15:05:02 rx [11061395.900438] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 26 15:05:02 rx [11061395.906435] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0 Jul 26 15:05:02 rx [11061395.913822] PKRU: 55555554 Jul 26 15:05:02 rx [11061395.916786] Call Trace: Jul 26 15:05:02 rx [11061395.919488] Jul 26 15:05:02 rx [11061395.921765] ? show_regs.cold+0x1a/0x1f Jul 26 15:05:02 rx [11061395.925859] ? __die+0x90/0xd9 Jul 26 15:05:02 rx [11061395.929169] ? no_context+0x196/0x380 Jul 26 15:05:02 rx [11061395.933088] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0 Jul 26 15:05:02 rx [11061395.938216] ? ip6_sublist_rcv_finish+0x3d/0x50 Jul 26 15:05:02 rx [11061395.943000] ? __bad_area_nosemaphore+0x50/0x1a0 Jul 26 15:05:02 rx [11061395.947873] ? bad_area_nosemaphore+0x16/0x20 Jul 26 15:05:02 rx [11061395.952486] ? do_user_addr_fault+0x267/0x450 Jul 26 15:05:02 rx [11061395.957104] ? ipv6_list_rcv+0x112/0x140 Jul 26 15:05:02 rx [11061395.961279] ? __do_page_fault+0x58/0x90 Jul 26 15:05:02 rx [11061395.965458] ? do_page_fault+0x2c/0xe0 Jul 26 15:05:02 rx [11061395.969465] ? page_fault+0x34/0x40 Jul 26 15:05:02 rx [11061395.973217] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.977313] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.981408] tcp_send_loss_probe+0x10b/0x220 Jul 26 15:05:02 rx [11061395.985937] tcp_write_timer_handler+0x1b4/0x240 Jul 26 15:05:02 rx [11061395.990809] tcp_write_timer+0x9e/0xe0 Jul 26 15:05:02 rx [11061395.994814] ? tcp_write_timer_handler+0x240/0x240 Jul 26 15:05:02 rx [11061395.999866] call_timer_fn+0x32/0x130 Jul 26 15:05:02 rx [11061396.003782] __run_timers.part.0+0x180/0x280 Jul 26 15:05:02 rx [11061396.008309] ? recalibrate_cpu_khz+0x10/0x10 Jul 26 15:05:02 rx [11061396.012841] ? native_x2apic_icr_write+0x30/0x30 Jul 26 15:05:02 rx [11061396.017718] ? lapic_next_even ---truncated---

Frequently asked questions

What is CVE-2024-47684?: In the Linux kernel, the following vulnerability has been resolved: tcp: check skb is non-NULL in tcp_rto_delta_us() We have some machines running stock Ubuntu 20.04.6 which is their 5.4.0-174-generic kernel that are running ceph and recently hit a null ptr dereference in tcp_rearm_rto(). Initially hitting it from the TLP path, but then later we also saw it getting hit from the RACK case as well. Here are examples of the oops messages we saw in each of those cases: Jul 26 15:05:02 rx [11061395.780353] BUG: kernel NULL pointer dereference, address: 0000000000000020 Jul 26 15:05:02 rx [11061395.787572] #PF: supervisor read access in kernel mode Jul 26 15:05:02 rx [11061395.792971] #PF: error_code(0x0000) - not-present page Jul 26 15:05:02 rx [11061395.798362] PGD 0 P4D 0 Jul 26 15:05:02 rx [11061395.801164] Oops: 0000 [#1] SMP NOPTI Jul 26 15:05:02 rx [11061395.805091] CPU: 0 PID: 9180 Comm: msgr-worker-1 Tainted: G W 5.4.0-174-generic #193-Ubuntu Jul 26 15:05:02 rx [11061395.814996] Hardware name: Supermicro SMC 2x26 os-gen8 64C NVME-Y 256G/H12SSW-NTR, BIOS 2.5.V1.2U.NVMe.UEFI 05/09/2023 Jul 26 15:05:02 rx [11061395.825952] RIP: 0010:tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.830656] Code: 87 ca 04 00 00 00 5b 41 5c 41 5d 5d c3 c3 49 8b bc 24 40 06 00 00 eb 8d 48 bb cf f7 53 e3 a5 9b c4 20 4c 89 ef e8 0c fe 0e 00 <48> 8b 78 20 48 c1 ef 03 48 89 f8 41 8b bc 24 80 04 00 00 48 f7 e3 Jul 26 15:05:02 rx [11061395.849665] RSP: 0018:ffffb75d40003e08 EFLAGS: 00010246 Jul 26 15:05:02 rx [11061395.855149] RAX: 0000000000000000 RBX: 20c49ba5e353f7cf RCX: 0000000000000000 Jul 26 15:05:02 rx [11061395.862542] RDX: 0000000062177c30 RSI: 000000000000231c RDI: ffff9874ad283a60 Jul 26 15:05:02 rx [11061395.869933] RBP: ffffb75d40003e20 R08: 0000000000000000 R09: ffff987605e20aa8 Jul 26 15:05:02 rx [11061395.877318] R10: ffffb75d40003f00 R11: ffffb75d4460f740 R12: ffff9874ad283900 Jul 26 15:05:02 rx [11061395.884710] R13: ffff9874ad283a60 R14: ffff9874ad283980 R15: ffff9874ad283d30 Jul 26 15:05:02 rx [11061395.892095] FS: 00007f1ef4a2e700(0000) GS:ffff987605e00000(0000) knlGS:0000000000000000 Jul 26 15:05:02 rx [11061395.900438] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 26 15:05:02 rx [11061395.906435] CR2: 0000000000000020 CR3: 0000003e450ba003 CR4: 0000000000760ef0 Jul 26 15:05:02 rx [11061395.913822] PKRU: 55555554 Jul 26 15:05:02 rx [11061395.916786] Call Trace: Jul 26 15:05:02 rx [11061395.919488] Jul 26 15:05:02 rx [11061395.921765] ? show_regs.cold+0x1a/0x1f Jul 26 15:05:02 rx [11061395.925859] ? __die+0x90/0xd9 Jul 26 15:05:02 rx [11061395.929169] ? no_context+0x196/0x380 Jul 26 15:05:02 rx [11061395.933088] ? ip6_protocol_deliver_rcu+0x4e0/0x4e0 Jul 26 15:05:02 rx [11061395.938216] ? ip6_sublist_rcv_finish+0x3d/0x50 Jul 26 15:05:02 rx [11061395.943000] ? __bad_area_nosemaphore+0x50/0x1a0 Jul 26 15:05:02 rx [11061395.947873] ? bad_area_nosemaphore+0x16/0x20 Jul 26 15:05:02 rx [11061395.952486] ? do_user_addr_fault+0x267/0x450 Jul 26 15:05:02 rx [11061395.957104] ? ipv6_list_rcv+0x112/0x140 Jul 26 15:05:02 rx [11061395.961279] ? __do_page_fault+0x58/0x90 Jul 26 15:05:02 rx [11061395.965458] ? do_page_fault+0x2c/0xe0 Jul 26 15:05:02 rx [11061395.969465] ? page_fault+0x34/0x40 Jul 26 15:05:02 rx [11061395.973217] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.977313] ? tcp_rearm_rto+0xe4/0x160 Jul 26 15:05:02 rx [11061395.981408] tcp_send_loss_probe+0x10b/0x220 Jul 26 15:05:02 rx [11061395.985937] tcp_write_timer_handler+0x1b4/0x240 Jul 26 15:05:02 rx [11061395.990809] tcp_write_timer+0x9e/0xe0 Jul 26 15:05:02 rx [11061395.994814] ? tcp_write_timer_handler+0x240/0x240 Jul 26 15:05:02 rx [11061395.999866] call_timer_fn+0x32/0x130 Jul 26 15:05:02 rx [11061396.003782] __run_timers.part.0+0x180/0x280 Jul 26 15:05:02 rx [11061396.008309] ? recalibrate_cpu_khz+0x10/0x10 Jul 26 15:05:02 rx [11061396.012841] ? native_x2apic_icr_write+0x30/0x30 Jul 26 15:05:02 rx [11061396.017718] ? lapic_next_even ---truncated---
How severe is CVE-2024-47684?: CVE-2024-47684 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2024-47684 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-47684?: CVE-2024-47684 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-47684?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-47684 have an EU (EUVD) identifier?: Yes. CVE-2024-47684 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-42604.
When was CVE-2024-47684 published?: CVE-2024-47684 was published on 2024-10-21 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.10.108:*:*:*:*:*:*:*

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