In the Linux kernel, the following vulnerability has been resolved: iio: pressure: bmp280: fix stack leak in bmp580 trigger handler bmp580_trigger_handler() declares its scan buffer on the stack without an initializer and then memcpy()s 3 bytes of 24-bit sensor data into each 4-byte __le32 field. The high byte of comp_temp and comp_press is left uninitialized, and the channel storagebits is 32, so two bytes of stack are pushed to userspace per scan. This is a regression from when the buffer
In the Linux kernel, the following vulnerability has been resolved:
iio: pressure: bmp280: fix stack leak in bmp580 trigger handler
bmp580_trigger_handler() declares its scan buffer on the stack without an initializer and then memcpy()s 3 bytes of 24-bit sensor data into each 4-byte __le32 field. The high byte of comp_temp and comp_press is left uninitialized, and the channel storagebits is 32, so two bytes of stack are pushed to userspace per scan.
This is a regression from when the buffer lived in the private data, the move to a stack-local struct dropped the implicit zeroing. bme280_trigger_handler() was fixed up to handle this bug, but this driver was not fixed because there was no padding hole, but rather a short-fill issue.
Fix this all by just zero-initializing the structure on the stack.
Why this VPI (explainable, experimental)
VPI breakdown
| Impact(default (no data)) | 55.00 |
| Exploitation signal(No additional exploitation signal) | ×1.00 |
| VPI | 55.00 |
VPI formula vpi-v1