# CVE-2025-38229: media: cxusb: no longer judge rbuf when the write fails > A local attacker can trigger a use of uninitialized memory in the cxusb driver, potentially leaking kernel memory contents. - **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Jul 2025 - **Updated:** 11 May 2026 - **Also known as:** AZL-64773, BELL-CVE-2025-38229, DEBIAN-CVE-2025-38229, GHSA-r243-xcvf-h6cr, ROOT-OS-DEBIAN-11-CVE-2025-38229, ROOT-OS-DEBIAN-12-CVE-2025-38229, ROOT-OS-UBUNTU-2204-CVE-2025-38229, ROOT-OS-UBUNTU-2404-CVE-2025-38229, UBUNTU-CVE-2025-38229 ## What is CVE-2025-38229? CVE-2025-38229 is a medium-severity vulnerability in Debian Debian Linux, published on 4 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim. ### Official 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 Weakness: CWE-908 (Use of Uninitialized Resource) ## Which versions are affected by CVE-2025-38229? It affects 2 products. Products: Debian Debian Linux, Linux kernel. ## How do I fix CVE-2025-38229? Apply the vendor's patch. ## Is CVE-2025-38229 being exploited? There is no known exploitation of CVE-2025-38229 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-38229 and fix it if it is affected. What it is: CVE-2025-38229 is a medium-severity vulnerability in Debian Debian Linux, published on 4 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2025-38229 in the wild and no public exploit code. Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-38229/ (Markdown: https://insights.sbomify.com/CVE-2025-38229/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38229 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38229 - OSV: https://osv.dev/vulnerability/CVE-2025-38229 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-38229/ Summaries are generated and may contain mistakes; the official description above is the record.