init/main.c: Fix potential static_command_line memory overflow

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: init/main.c: Fix potential static_command_line memory overflow We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for static_command_line, but the strings copied into static_command_line are extra_command_line and command_line, rather than extra_command_line and boot_command_line. When strlen(command_line) > strlen(boot_command_line), static_command_line will overflow. This patch just recovers strlen(command_line) which was miss-consolidated with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")

References

• https://git.kernel.org/stable/c/2ef607ea103616aec0289f1b65d103d499fa903a
• https://git.kernel.org/stable/c/0dc727a4e05400205358a22c3d01ccad2c8e1fe4
• https://git.kernel.org/stable/c/76c2f4d426a5358fced5d5990744d46f10a4ccea
• https://git.kernel.org/stable/c/81cf85ae4f2dd5fa3e43021782aa72c4c85558e8
• https://git.kernel.org/stable/c/936a02b5a9630c5beb0353c3085cc49d86c57034
• https://git.kernel.org/stable/c/46dad3c1e57897ab9228332f03e1c14798d2d3b9