Andreas Kling 862b3ccb4e Kernel: Enforce W^X between sys$mmap() and sys$execve() ...

It's now an error to sys$mmap() a file as writable if it's currently
mapped executable by anyone else.

It's also an error to sys$execve() a file that's currently mapped
writable by anyone else.

This fixes a race condition vulnerability where one program could make
modifications to an executable while another process was in the kernel,
in the middle of exec'ing the same executable.

Test: Kernel/elf-execve-mmap-race.cpp

2020-01-18 23:40:12 +01:00

2.5 KiB

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