CVE-2023-53121: linux kernel — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: tcp_make_synack() can be called from process context tcp_rtx_synack() now could be called in process context as explained in 0a375c822497 ("tcp: tcp_rtx_synack() can be called from process context"). tcp_rtx_synack() might call tcp_make_synack(), which will touch per-CPU variables with preemption enabled. This causes the following BUG: BUG: using __this_cpu_add() in preemptible [00000000] code: ThriftIO1/5464 caller is tcp_make_synack+0x841/0xac0 Call Trace: <TASK> dump_stack_lvl+0x10d/0x1a0 check_preemption_disabled+0x104/0x110 tcp_make_synack+0x841/0xac0 tcp_v6_send_synack+0x5c/0x450 tcp_rtx_synack+0xeb/0x1f0 inet_rtx_syn_ack+0x34/0x60 tcp_check_req+0x3af/0x9e0 tcp_rcv_state_process+0x59b/0x2030 tcp_v6_do_rcv+0x5f5/0x700 release_sock+0x3a/0xf0 tcp_sendmsg+0x33/0x40 ____sys_sendmsg+0x2f2/0x490 __sys_sendmsg+0x184/0x230 do_syscall_64+0x3d/0x90 Avoid calling __TCP_INC_STATS() with will touch per-cpu variables. Use TCP_INC_STATS() which is safe to be called from context switch.

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Products

Vendor	Product	Versions
linux	linux_kernel	3.7 — 4.14.311
linux	linux_kernel	4.15 — 4.19.279
linux	linux_kernel	4.20 — 5.4.238
linux	linux_kernel	5.5 — 5.10.176
linux	linux_kernel	5.11 — 5.15.104
linux	linux_kernel	5.16 — 6.1.21
linux	linux_kernel	6.2 — 6.2.8
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/442aa78ed70188b21ccd8669738448702c0a3281 https://git.kernel.org/stable/c/7613cde8c0c1f02a7ec2e1d536c01b65b135fc1c https://git.kernel.org/stable/c/77ad58bca0119e8cc3e0e9d91a3f22caa66e4dfa https://git.kernel.org/stable/c/9180aa4622a720b433e842b4d3aa34d73eec577a https://git.kernel.org/stable/c/ad07290d63ff6689f50565b02f5b6f34ec15a5ca https://git.kernel.org/stable/c/bced3f7db95ff2e6ca29dc4d1c9751ab5e736a09 https://git.kernel.org/stable/c/d493d4fe88195a144d6a277a90062a7534ed2192 https://git.kernel.org/stable/c/e23ca307745be3df7fe9762f3e2a7e311a57852e

Frequently Asked Questions

What is CVE-2023-53121? +

In the Linux kernel, the following vulnerability has been resolved: tcp: tcp_make_synack() can be called from process context tcp_rtx_synack() now could be called in process context as explained in 0a375c822497 ("tcp: tcp_rtx_synack() can be called from process context"). tcp_rtx_synack() might call tcp_make_synack(), which will touch per-CPU variables with preemption enabled. This causes the following BUG: BUG: using __this_cpu_add() in preemptible [00000000] code: ThriftIO1/5464 caller is tcp_make_synack+0x841/0xac0 Call Trace: <TASK> dump_stack_lvl+0x10d/0x1a0 check_preemption_disabled+0x104/0x110 tcp_make_synack+0x841/0xac0 tcp_v6_send_synack+0x5c/0x450 tcp_rtx_synack+0xeb/0x1f0 inet_rtx_syn_ack+0x34/0x60 tcp_check_req+0x3af/0x9e0 tcp_rcv_state_process+0x59b/0x2030 tcp_v6_do_rcv+0x5f5/0x700 release_sock+0x3a/0xf0 tcp_sendmsg+0x33/0x40 ____sys_sendmsg+0x2f2/0x490 __sys_sendmsg+0x184/0x230 do_syscall_64+0x3d/0x90 Avoid calling __TCP_INC_STATS() with will touch per-cpu variables. Use TCP_INC_STATS() which is safe to be called from context switch. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2023-53121? +

CVE-2023-53121 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2023-53121? +

CVE-2023-53121 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-53121? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2023-53121