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CVE-2026-53194

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, and 2 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: total

Summary

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.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: no · Technical impact: total

  3. Record last updated

Affected versions

  • Linux Linux

    From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 60af1fd82983c26604102e63a3fcc822c186cceb; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 0a57320f71941d4e0b1307453c9a1f0939afe666; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 14147b7963685957839c76ba8094924e22777d79; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in a1288cd700f721c1a119c4f1e8efa234e59caada; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 70d86e355c564b5510fde61361df014f5476c83e; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 372f33ebed747d91870f57c0a2e62884a870bffa; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in bde742b076cbe26ecc89c8c68c76ae076a524d02; From 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 · fixed in 96d47e40bf9db4a9efd5c8fb53287a508d165f14

  • Linux Linux

    2.6.35

  • KernelLinux

    From 2.6.35 · fixed in 5.10.259; From 5.11.0 · fixed in 5.15.210; From 5.16.0 · fixed in 6.1.176; From 6.2.0 · fixed in 6.6.143; From 6.7.0 · fixed in 6.12.94; From 6.13.0 · fixed in 6.18.36; From 6.19.0 · fixed in 7.0.13

References 8

git.kernel.org