update: add monitoring of mprotect parameters

[loresuso]

What type of PR is this?

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/kind bug

/kind cleanup

/kind design

/kind documentation

/kind failing-test

/kind feature

Any specific area of the project related to this PR?

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/area build

/area driver-kmod

/area driver-ebpf

/area libscap

/area libsinsp

/area tests

/area proposals

What this PR does / why we need it:
I noticed that we were missing monitoring parameters of the mprotect syscall. I think that the latter can be used for malicious purposes, for instance:

• in ROP chains to make the stack executable again to bypass the NX protection and execute shellcode injected on it. (transition W->X)
• malware that self-modifies, injecting useless instructions to avoid detection like push/pop from stack, add/subtract the same register, and so on (transition X->W->X)
• unpacker that decrypts/uncompresses malware in memory and make it executable

In general, it may be interesting monitoring pages permissions transitions: every time a page passes from writable permissions to executable ones and vice versa, it may be a clue of something malicious going on. These transitions may be monitored by inspecting /proc/<pid>/maps on process startup and using the parameters of every mprotect and mmap syscalls to check if a valid transition occurred or not. Let me know what do you think about this, maybe we can use this PR to share more ideas!

You can test this system call with this simple C program.
Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

update: add monitoring of mprotect parameters

[poiana]

Hi @loresuso. Thanks for your PR.

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[FedeDP]

This is great! Thank you!

[poiana]

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This is great! Thank you!

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[jasondellaluce]

This is great!!

[FedeDP]

/ok-to-test

[leogr]

/approve

[poiana]

LGTM label has been added.

Git tree hash: 3d6af6c5775505216a7a2d7bcb8282e0f61c1e9a

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: leogr, loresuso

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