CVE-2024-44950

Summary

In the Linux kernel, the following vulnerability has been resolved:

serial: sc16is7xx: fix invalid FIFO access with special register set

When enabling access to the special register set, Receiver time-out and RHR interrupts can happen. In this case, the IRQ handler will try to read from the FIFO thru the RHR register at address 0x00, but address 0x00 is mapped to DLL register, resulting in erroneous FIFO reading.

Call graph example: sc16is7xx_startup(): entry sc16is7xx_ms_proc(): entry sc16is7xx_set_termios(): entry sc16is7xx_set_baud(): DLH/DLL = $009C –> access special register set sc16is7xx_port_irq() entry –> IIR is 0x0C sc16is7xx_handle_rx() entry sc16is7xx_fifo_read(): –> unable to access FIFO (RHR) because it is mapped to DLL (LCR=LCR_CONF_MODE_A) sc16is7xx_set_baud(): exit –> Restore access to general register set

Fix the problem by claiming the efr_lock mutex when accessing the Special register set.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxdfeae619d781dee61666d5551b93ba3be755a86b < cc6a3f35bc9b3a8da1b195420a2e8d9fdadfa831affected
LinuxLinuxdfeae619d781dee61666d5551b93ba3be755a86b < dc5ead0e8fc5ef53b8553394d4aab60c277976b3affected
LinuxLinuxdfeae619d781dee61666d5551b93ba3be755a86b < 6a6730812220a9a5ce4003eb347da1ee5abd06b0affected
LinuxLinuxdfeae619d781dee61666d5551b93ba3be755a86b < 7d3b793faaab1305994ce568b59d61927235f57baffected
LinuxLinux3.16affected
LinuxLinux0 < 3.16unaffected
LinuxLinux6.1.120 <= 6.1.*unaffected
LinuxLinux6.6.64 <= 6.6.*unaffected
LinuxLinux6.10.5 <= 6.10.*unaffected
LinuxLinux6.11 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References