In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks()
The check_command_size_in_blocks() function calculates the data size
in bytes by left shifting common->data_size_from_cmnd by the block
size (common->curlun->blkbits). However, it does not validate whether
this shift operation will cause an integer overflow.
Initially, the block size is set up in fsg_lun_open() , and the
common->data_size_from_cmnd is set up in do_scsi_command(). During
initialization, there is no integer overflow check for the interaction
between two variables.
So if a malicious USB host sends a SCSI READ or WRITE command
requesting a large amount of data (common->data_size_from_cmnd), the
left shift operation can wrap around. This results in a truncated data
size, which can bypass boundary checks and potentially lead to memory
corruption or out-of-bounds accesses.
Fix this by using the check_shl_overflow() macro to safely perform the shift and catch any overflows.