GHSA-R243-XCVF-H6CR
Vulnerability from github – Published: 2025-07-04 15:31 – Updated: 2025-12-18 21:31In 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
{
"affected": [],
"aliases": [
"CVE-2025-38229"
],
"database_specific": {
"cwe_ids": [
"CWE-908"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-04T14:15:32Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cxusb: no longer judge rbuf when the write fails\n\nsyzbot reported a uninit-value in cxusb_i2c_xfer. [1]\n\nOnly when the write operation of usb_bulk_msg() in dvb_usb_generic_rw()\nsucceeds and rlen is greater than 0, the read operation of usb_bulk_msg()\nwill be executed to read rlen bytes of data from the dvb device into the\nrbuf.\n\nIn this case, although rlen is 1, the write operation failed which resulted\nin the dvb read operation not being executed, and ultimately variable i was\nnot initialized.\n\n[1]\nBUG: KMSAN: uninit-value in cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline]\nBUG: KMSAN: uninit-value in cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196\n cxusb_gpio_tuner drivers/media/usb/dvb-usb/cxusb.c:124 [inline]\n cxusb_i2c_xfer+0x153a/0x1a60 drivers/media/usb/dvb-usb/cxusb.c:196\n __i2c_transfer+0xe25/0x3150 drivers/i2c/i2c-core-base.c:-1\n i2c_transfer+0x317/0x4a0 drivers/i2c/i2c-core-base.c:2315\n i2c_transfer_buffer_flags+0x125/0x1e0 drivers/i2c/i2c-core-base.c:2343\n i2c_master_send include/linux/i2c.h:109 [inline]\n i2cdev_write+0x210/0x280 drivers/i2c/i2c-dev.c:183\n do_loop_readv_writev fs/read_write.c:848 [inline]\n vfs_writev+0x963/0x14e0 fs/read_write.c:1057\n do_writev+0x247/0x5c0 fs/read_write.c:1101\n __do_sys_writev fs/read_write.c:1169 [inline]\n __se_sys_writev fs/read_write.c:1166 [inline]\n __x64_sys_writev+0x98/0xe0 fs/read_write.c:1166\n x64_sys_call+0x2229/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:21\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f",
"id": "GHSA-r243-xcvf-h6cr",
"modified": "2025-12-18T21:31:34Z",
"published": "2025-07-04T15:31:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38229"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/04354c529c8246a38ae28f713fd6bfdc028113bc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/390b864e3281802109dfe56e508396683e125653"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/41807a5f67420464ac8ee7741504f6b5decb3b7c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/73fb3b92da84637e3817580fa205d48065924e15"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/77829a5f5a74026b888b0529628475b29750cef4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/84eca597baa346f09b30accdaeca10ced3eeba2d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8b35b50b7e98d8e9a0a27257c8424448afae10de"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9bff888c92f5c25effbb876d22a793c2388c1ccc"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.