Bug #20592: Interrupting Addrinfo causes Segmentation fault on alpine

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.4.0preview1 (2024-05-16 master 9d69619623) [x86_64-linux-musl]
• Backport: 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: REQUIRED

[haukot (Dmitry Davydov)]

On Alpine 3.20 got a segfault when interrupting Addrinfo request which would resolve with error.

Same on
ruby 3.3.1 (2024-04-23 revision c56cd86388) [x86_64-linux-musl]

Tried on docker image alpine3.20 and ruby:3.4.0-preview1-alpine.

# test.rb

require 'socket'
require 'timeout'

begin
  Addrinfo.ip("1234.example.com")
rescue StandardError => e
  puts e
end

sleep 10 # wait getaddrinfo to resolve and fail

/app # ruby test.rb
execution expired
[BUG] Segmentation fault at 0x0000000000000028
ruby 3.4.0preview1 (2024-05-16 master 9d69619623) [x86_64-linux-musl]

-- Machine register context ------------------------------------------------
 RIP: 0x00007fefe4cd4886 RBP: 0x0000000000000001 RSP: 0x00007fefc95d3a10
 RAX: 0x0000000000000001 RBX: 0x00007fefc94212e0 RCX: 0x00007fefc95d0b70
 RDX: 0x0000000000000010 RDI: 0x0000000000000000 RSI: 0x00007fefc95d08f0
  R8: 0x0000000000000000  R9: 0x0000000000000000 R10: 0x0000000000000000
 R11: 0x0000000000000217 R12: 0x00007fefc9421340 R13: 0x00007fff5a0ec750
 R14: 0x00007fefe4649b10 R15: 0x00007fefc95d3b38 EFL: 0x0000000000010202

-- Other runtime information -----------------------------------------------

gdb logs

/app # gdb -q --args ruby test.rb
(gdb) run
Starting program: /usr/local/bin/ruby test.rb
warning: Error disabling address space randomization: Operation not permitted
[New LWP 36]
[New LWP 37]
[New LWP 38]
execution expired

Thread 4 "ruby" received signal SIGSEGV, Segmentation fault.
[Switching to LWP 38]
0x00007f0a2c33b886 in freeaddrinfo (p=0x0) at src/network/freeaddrinfo.c:10
warning: 10     src/network/freeaddrinfo.c: No such file or directory
(gdb) bt
#0  0x00007f0a2c33b886 in freeaddrinfo (p=0x0) at src/network/freeaddrinfo.c:10
#1  0x00007f0a10c1e940 in do_getaddrinfo (ptr=0x7f0a10f61200) at raddrinfo.c:426
#2  0x00007f0a2c35c349 in start (p=0x7f0a10afaa88) at src/thread/pthread_create.c:207
#3  0x00007f0a2c35e95f in __clone () at src/thread/x86_64/clone.s:22
Backtrace stopped: frame did not save the PC
(gdb) info args
p = 0x0

There are no errors if Addrinfo resolves with data

  Timeout.timeout(0.01) { Addrinfo.ip("ruby-lang.org") } # finishes correctly

The problem is that freeaddrinfo on alpine does not accept a NULL pointer (ref
https://git.musl-libc.org/cgit/musl/tree/src/network/freeaddrinfo.c)

[haukot (Dmitry Davydov)]

PR https://github.com/ruby/ruby/pull/11045

[haukot (Dmitry Davydov)]

• Description updated (diff)

[haukot (Dmitry Davydov)]

• Description updated (diff)

[haukot (Dmitry Davydov)]

• File segfault.txt segfault.txt added
• File segfault_gdb.txt segfault_gdb.txt added

[haukot (Dmitry Davydov)]

• File deleted (segfault_gdb)

[haukot (Dmitry Davydov)]

• File deleted (segfault)

[haukot (Dmitry Davydov)]

• Status changed from Open to Closed

Applied in changeset git|fba8aff7af450e476e97b62385427dfa51850955.

---

[Bug #20592] Fix segfault when sending NULL to freeaddrinfo

On alpine freeaddrinfo does not accept NULL pointer

[mame (Yusuke Endoh)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN to 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: REQUIRED

Thanks! Looks good to me. I have merged your PR.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: REQUIRED to 3.1: UNKNOWN, 3.2: REQUIRED, 3.3: REQUIRED