Linux syscall parameter verification

[angods]

https://wiki.osdev.org/System_Calls mentions, that Linux fails to verify pointers from userland. Can someone explain if that's still (or was ever) true and why exactly did Linux lack such safety checks?

Thanks

[thewrongchristian]

https://wiki.osdev.org/System_Calls mentions, that Linux fails to verify pointers from userland. Can someone explain if that's still (or was ever) true and why exactly did Linux lack such safety checks?

Thanks

I don't think that is true. Linux provides access checks and copying to/from user memory:

https://elixir.bootlin.com/linux/v5.14. ... cess.h#L52

[angods]

https://wiki.osdev.org/System_Calls mentions, that Linux fails to verify pointers from userland. Can someone explain if that's still (or was ever) true and why exactly did Linux lack such safety checks?

Thanks

I don't think that is true. Linux provides access checks and copying to/from user memory:

https://elixir.bootlin.com/linux/v5.14. ... cess.h#L52

Then the osdev page should be corrected

[Octocontrabass]

Go right ahead.

[nullplan]

I was getting around to that...

Sorry. I added the wrong sentence, and I also just removed it. I originally got tripped up by the difference between get_user and __get_user. The former verifies the pointer is in range, the latter doesn't.