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USB: serial: kl5kusb105: fix bulk-out buffer overflow

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: USB: serial: kl5kusb105: fix bulk-out buffer overflow klsi_105_prepare_write_buffer() is called by the generic write path with the bulk-out buffer and its size (bulk_out_size, 64 bytes). It stores a two-byte length header at the start of the buffer and copies the payload from the write fifo starting at buf + KLSI_HDR_LEN, but passes the full buffer size as the number of bytes to copy: count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size, &port->lock); When the fifo holds at least size bytes, size bytes are copied starting two bytes into the size-byte buffer, writing KLSI_HDR_LEN bytes past its end. Copy at most size - KLSI_HDR_LEN bytes instead, leaving room for the header as safe_serial already does. Writing bulk_out_size or more bytes to the tty triggers a slab out-of-bounds write, observed with KASAN by emulating the device with dummy_hcd and raw-gadget: BUG: KASAN: slab-out-of-bounds in kfifo_copy_out+0x83/0xc0 Write of size 64 at addr ffff888112c62202 by task python3 kfifo_copy_out klsi_105_prepare_write_buffer [kl5kusb105] usb_serial_generic_write_start [usbserial] Allocated by task 139: usb_serial_probe [usbserial] The buggy address is located 2 bytes inside of allocated 64-byte region The out-of-bounds write no longer occurs with this change applied.

Announced Group revision 1
Original source ↗

CVE-2026-53194

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-53194

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "60af1fd82983c26604102e63a3fcc822c186cceb",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "0a57320f71941d4e0b1307453c9a1f0939afe666",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "14147b7963685957839c76ba8094924e22777d79",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "a1288cd700f721c1a119c4f1e8efa234e59caada",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "70d86e355c564b5510fde61361df014f5476c83e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "372f33ebed747d91870f57c0a2e62884a870bffa",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "bde742b076cbe26ecc89c8c68c76ae076a524d02",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
        "lessThan": "96d47e40bf9db4a9efd5c8fb53287a508d165f14",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/usb/serial/kl5kusb105.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.35"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.35",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.259",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.210",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.176",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.143",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.94",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.36",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.0.13",
        "versionType": "semver",
        "lessThanOrEqual": "7.0.*"
      },
      {
        "status": "unaffected",
        "version": "7.1",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/usb/serial/kl5kusb105.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-53194

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#40775 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement

Revision history

  1. CVE-2026-53194 · Revision 1Source updated