fatal error: mlock failed

[martinvonwittich]

When I setup Firefox to use nordvpn-proxy as a SOCKS proxy, nordvpn-proxy quickly dies with the following error message:

runtime: mlock of signal stack failed: 12                                                                                                                                   
runtime: increase the mlock limit (ulimit -l) or                                                                                                                            
runtime: update your kernel to 5.3.15+, 5.4.2+, or 5.5+                                                                                                                     
fatal error: mlock failed                                                                                                                                                   
                                                                                                                                                                            
runtime stack:                                                                                                                                                              
runtime.throw(0xb9545e, 0xc)                                                                                                                                                
        /usr/local/go/src/runtime/panic.go:1112 +0x72                                                                                                                       
runtime.mlockGsignal(0xc000d34c00)                                                                                                                                          
        /usr/local/go/src/runtime/os_linux_x86.go:72 +0x107                                                                                                                 
runtime.mpreinit(0xc000d3f880)                                                                                                                                              
        /usr/local/go/src/runtime/os_linux.go:341 +0x78                                                                                                                     
runtime.mcommoninit(0xc000d3f880)                                                                                                                                           
        /usr/local/go/src/runtime/proc.go:630 +0x108                                                                                                                        
runtime.allocm(0xc00003d000, 0xbc1f28, 0x782579f7fd00)                                                                                                                      
        /usr/local/go/src/runtime/proc.go:1390 +0x14e                                                                                                                       
runtime.newm(0xbc1f28, 0xc00003d000)                                                                                                                                        
        /usr/local/go/src/runtime/proc.go:1704 +0x39                                                                                                                        
runtime.startm(0x0, 0xc0003b2101)                                                                                                                                           
        /usr/local/go/src/runtime/proc.go:1869 +0x12a                                                                                                                       
runtime.wakep(...)                                                                                                                                                          
        /usr/local/go/src/runtime/proc.go:1953                                                                                                                              
runtime.resetspinning()                                                                                                                                                     
        /usr/local/go/src/runtime/proc.go:2415 +0x93                                                                                                                        
runtime.schedule()                                                                                                                                                          
        /usr/local/go/src/runtime/proc.go:2527 +0x2de                                                                                                                       
runtime.park_m(0xc000ba5b00)                                                                                                                                                
        /usr/local/go/src/runtime/proc.go:2690 +0x9d                                                                                                                        
runtime.mcall(0x800000)                                                                                                                                                     
        /usr/local/go/src/runtime/asm_amd64.s:318 +0x5b                                                                                                                     
                                                                                                                                                                            
goroutine 1 [chan receive]:                                                                                                                                                 
main.wait(0xc000f74e90, 0xbc18d8, 0xc000310090)                                                                                                                             
        /builds/nordvpn/apps-source/linux-app/src/cmd/daemon/wait.go:17 +0xbd                                                                                               
main.main()                                                                                                                                                                 
        /builds/nordvpn/apps-source/linux-app/src/cmd/daemon/main.go:153 +0xb64                                                                                             
[pages of pages of stack traces...]
2020-12-01 23:50:03,582 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,583 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,667 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,669 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,832 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,833 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,961 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:03,962 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:04,134 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:04,135 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:04,170 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       
2020-12-01 23:50:04,171 ERROR [rusty_socks::connection] Cannot assign requested address (os error 99)                                                                       

Apparently this is a golang workaround for a kernel bug which is probably hampered by Docker restrictions. I was able to resolve this by adding --cap-add IPC_LOCK to the docker run command line. Might be worth a note in the docs.

[twitchax]

Cool: will do!