serial: core: check uartclk for zero to avoid divide by zero
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-369.
Summary
In the Linux kernel, the following vulnerability has been resolved: serial: core: check uartclk for zero to avoid divide by zero Calling ioctl TIOCSSERIAL with an invalid baud_base can result in uartclk being zero, which will result in a divide by zero error in uart_get_divisor(). The check for uartclk being zero in uart_set_info() needs to be done before other settings are made as subsequent calls to ioctl TIOCSSERIAL for the same port would be impacted if the uartclk check was done where uartclk gets set. Oops: divide error: 0000 PREEMPT SMP KASAN PTI RIP: 0010:uart_get_divisor (drivers/tty/serial/serial_core.c:580) Call Trace: <TASK> serial8250_get_divisor (drivers/tty/serial/8250/8250_port.c:2576 drivers/tty/serial/8250/8250_port.c:2589) serial8250_do_set_termios (drivers/tty/serial/8250/8250_port.c:502 drivers/tty/serial/8250/8250_port.c:2741) serial8250_set_termios (drivers/tty/serial/8250/8250_port.c:2862) uart_change_line_settings (./include/linux/spinlock.h:376 ./include/linux/serial_core.h:608 drivers/tty/serial/serial_core.c:222) uart_port_startup (drivers/tty/serial/serial_core.c:342) uart_startup (drivers/tty/serial/serial_core.c:368) uart_set_info (drivers/tty/serial/serial_core.c:1034) uart_set_info_user (drivers/tty/serial/serial_core.c:1059) tty_set_serial (drivers/tty/tty_io.c:2637) tty_ioctl (drivers/tty/tty_io.c:2647 drivers/tty/tty_io.c:2791) __x64_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:907 fs/ioctl.c:893 fs/ioctl.c:893) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Rule: add
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.12 and later | 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.105, 6.6.46, 6.10.5, 6.11 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.12 and later Fixed in 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.105, 6.6.46, 6.10.5, 6.11 Patch available CNA
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.19.320; 4.20 to before 5.4.282; 5.5 to before 5.10.224; 5.11 to before 5.15.165; 5.16 to before 6.1.105; 6.2 to before 6.6.46; 6.7 to before 6.10.5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* | 6.11 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* | 6.11 rc2 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.19.320; 4.20 to before 5.4.282; 5.5 to before 5.10.224; 5.11 to before 5.15.165; 5.16 to before 6.1.105; 6.2 to before 6.6.46; 6.7 to before 6.10.5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* Versions 6.11 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* Versions 6.11 rc2 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.105, 6.6.46, 6.10.5, 6.11
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2024-43893
- 2026-10-03 Alias added: GHSA-v66h-w7q8-587v
References
Patch 8
- https://git.kernel.org/stable/c/3bbd90fca824e6fd61fb20f6dd2b0fa5f8b14bba
- https://git.kernel.org/stable/c/55b2a5d331a6ceb1c4372945fdb77181265ba24f
- https://git.kernel.org/stable/c/52b138f1021113e593ee6ad258ce08fe90693a9e
- https://git.kernel.org/stable/c/9196e42a3b8eeff1707e6ef769112b4b6096be49
- https://git.kernel.org/stable/c/e13ba3fe5ee070f8a9dab60029d52b1f61da5051
- https://git.kernel.org/stable/c/e3ad503876283ac3fcca922a1bf243ef9eb0b0e2
- https://git.kernel.org/stable/c/68dc02f319b9ee54dc23caba742a5c754d1cccc8
- https://git.kernel.org/stable/c/6eabce6608d6f3440f4c03aa3d3ef50a47a3d193
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-43893 · CVE Program
- CVE-2024-43893 · NVD
- FIRST EPSS
- GHSA-v66h-w7q8-587v · GitHub Advisory Database · CC BY 4.0
- CVE-2024-43893 · Red Hat security data · CC BY 4.0
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