CVE-2025-38229: In the Linux kernel, the following vulnerability has been resolved: media: cxusb: no longer judge rbuf when the write fails syzbot reported a uninit...

Description

In the Linux kernel, the following vulnerability has been resolved: media: cxusb: no longer judge rbuf when the write fails syzbot reported a uninit-value in cxusb_i2c_xfer. [1] Only when the write operation of usb_bulk_msg() in dvb_usb_generic_rw() succeeds and rlen is greater than 0, the read operation of usb_bulk_msg() will be executed to read rlen bytes of data from the dvb device into the rbuf. In this case, although rlen is 1, the write operation failed which resulted in the dvb read operation not being executed, and ultimately variable i was not initialized. [1] BUG: KMSAN: uninit-value in cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline] BUG: KMSAN: uninit-value in cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196 cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline] cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196 __i2c_transfer+0xe25/0x3150 drivers/i2c/i2c-core-base.c:-1 i2c_transfer+0x317/0x4a0 drivers/i2c/i2c-core-base.c:2315 i2c_transfer_buffer_flags+0x125/0x1e0 drivers/i2c/i2c-core-base.c:2343 i2c_master_send include/linux/i2c.h:109 [inline] i2cdev_write+0x210/0x280 drivers/i2c/i2c-dev.c:183 do_loop_readv_writev fs/read_write.c:848 [inline] vfs_writev+0x963/0x14e0 fs/read_write.c:1057 do_writev+0x247/0x5c0 fs/read_write.c:1101 __do_sys_writev fs/read_write.c:1169 [inline] __se_sys_writev fs/read_write.c:1166 [inline] __x64_sys_writev+0x98/0xe0 fs/read_write.c:1166 x64_sys_call+0x2229/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:21 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Metrics

CVSS 3.1

5.5/10

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

EPSS Probability

0.15%

4.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-908

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 2.6.14, < 5.4.296
Linux	Linux Kernel	>= 5.5, < 5.10.239
Linux	Linux Kernel	>= 5.11, < 5.15.186
Linux	Linux Kernel	>= 5.16, < 6.1.142
Linux	Linux Kernel	>= 6.2, < 6.6.95
Linux	Linux Kernel	>= 6.7, < 6.12.35
Linux	Linux Kernel	>= 6.13, < 6.15.4
Linux	Linux Kernel	2.6.13
Debian	Debian Linux	11.0

References

Timeline

Published: Jul 4, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-38229?

In the Linux kernel, the following vulnerability has been resolved: media: cxusb: no longer judge rbuf when the write fails syzbot reported a uninit-value in cxusb_i2c_xfer. [1] Only when the write operation of usb_bulk_msg() in dvb_usb_generic_rw() succeeds and rlen is greater than 0, the read operation of usb_bulk_msg() will be executed to read rlen bytes of data from the dvb device into the rbuf. In this case, although rlen is 1, the write operation failed which resulted in the dvb read operation not being executed, and ultimately variable i was not initialized. [1] BUG: KMSAN: uninit-value in cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline] BUG: KMSAN: uninit-value in cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196 cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline] cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196 __i2c_transfer+0xe25/0x3150 drivers/i2c/i2c-core-base.c:-1 i2c_transfer+0x317/0x4a0 drivers/i2c/i2c-core-base.c:2315 i2c_transfer_buffer_flags+0x125/0x1e0 drivers/i2c/i2c-core-base.c:2343 i2c_master_send include/linux/i2c.h:109 [inline] i2cdev_write+0x210/0x280 drivers/i2c/i2c-dev.c:183 do_loop_readv_writev fs/read_write.c:848 [inline] vfs_writev+0x963/0x14e0 fs/read_write.c:1057 do_writev+0x247/0x5c0 fs/read_write.c:1101 __do_sys_writev fs/read_write.c:1169 [inline] __se_sys_writev fs/read_write.c:1166 [inline] __x64_sys_writev+0x98/0xe0 fs/read_write.c:1166 x64_sys_call+0x2229/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:21 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f

How severe is CVE-2025-38229?

CVE-2025-38229 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2025-38229?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.