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CVE PROGRAM SOURCE RECORDUnscored

CVE-2024-26998

serial: core: Clearing the circular buffer before NULLifying it

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: serial: core: Clearing the circular buffer before NULLifying it The circular buffer is NULLified in uart_tty_port_shutdown() under the spin lock. However, the PM or other timer based callbacks may still trigger after this event without knowning that buffer pointer is not valid. Since the serial code is a bit inconsistent in checking the buffer state (some rely on the head-tail positions, some on the buffer pointer), it's better to have both aligned, i.e. buffer pointer to be NULL and head-tail possitions to be the same, meaning it's empty. This will prevent asynchronous calls to dereference NULL pointer as reported recently in 8250 case: BUG: kernel NULL pointer dereference, address: 00000cf5 Workqueue: pm pm_runtime_work EIP: serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) ... ? serial8250_tx_chars (drivers/tty/serial/8250/8250_port.c:1809) __start_tx (drivers/tty/serial/8250/8250_port.c:1551) serial8250_start_tx (drivers/tty/serial/8250/8250_port.c:1654) serial_port_runtime_suspend (include/linux/serial_core.h:667 drivers/tty/serial/serial_port.c:63) __rpm_callback (drivers/base/power/runtime.c:393) ? serial_port_remove (drivers/tty/serial/serial_port.c:50) rpm_suspend (drivers/base/power/runtime.c:447) The proposed change will prevent ->start_tx() to be called during suspend on shut down port.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 434beb66368d4fb4d3119c2116b9398500adbf47 to < 7ae7104d54342433a3a73975f6569beefdd86350affected
  • 43066e32227ecde674e8ae1fcdd4a1ede67680c2 to < bb1118905e875c111d7ccef9aee86ac5e4e7f985affected
  • 43066e32227ecde674e8ae1fcdd4a1ede67680c2 to < 9cf7ea2eeb745213dc2a04103e426b960e807940affected
  • a629a9b2f7699314a4abe8fbc37b0ee667b60f33affected
  • 6.6.24 to < 6.6.29affected
  • 6.7.12 to < 6.8affected

Linux Linux

Default version status: affected

  • 6.8affected
  • 0 to < 6.8unaffected
  • 6.6.29 to ≤ 6.6.*unaffected
  • 6.8.8 to ≤ 6.8.*unaffected
  • 6.9 to ≤ *unaffected

References