uprobes/x86: Harden uretprobe syscall trampoline check

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: uprobes/x86: Harden uretprobe syscall trampoline check Jann reported a possible issue when trampoline_check_ip returns address near the bottom of the address space that is allowed to call into the syscall if uretprobes are not set up: https://lore.kernel.org/bpf/202502081235.5A6F352985@keescook/T/#m9d416df341b8fbc11737dacbcd29f0054413cbbf Though the mmap minimum address restrictions will typically prevent creating mappings there, let's make sure uretprobe syscall checks for that.

References

• https://git.kernel.org/stable/c/c35771342e47d58ab9433f3be1c3c30f2c5fa4f3
• https://git.kernel.org/stable/c/b0065d712049c87e1994c6eac00c6a637e39b325
• https://git.kernel.org/stable/c/d4e48b8d59fe162938a5004ace698c847e6a3207
• https://git.kernel.org/stable/c/fa6192adc32f4fdfe5b74edd5b210e12afd6ecc0