Segfault on roundcube config file

[divinity76]

possible duplicate of #3

trying to process the following config file on Ubuntu 18.04 with commit 7b590f7aefef35214125b4fd632c041a5c4fec13 (newest commit as of writing, 2019-09-28), results in a segfault, strace at bottom,

config file:

# Those aliases do not work properly with several hosts on your apache server
# Uncomment them to use it or adapt them to your configuration
#    Alias /roundcube /var/lib/roundcube

<Directory /var/lib/roundcube/>
  Options +FollowSymLinks
  # This is needed to parse /var/lib/roundcube/.htaccess. See its
  # content before setting AllowOverride to None.
  AllowOverride All
  <IfVersion >= 2.3>
    Require all granted
  </IfVersion> 
  <IfVersion < 2.3>
    Order allow,deny
    Allow from all
  </IfVersion>
</Directory>

# Protecting basic directories:
<Directory /var/lib/roundcube/config>
        Options -FollowSymLinks
        AllowOverride None
</Directory>

<Directory /var/lib/roundcube/temp>
        Options -FollowSymLinks
        AllowOverride None
        <IfVersion >= 2.3>
          Require all denied
        </IfVersion> 
        <IfVersion < 2.3>
          Order allow,deny
          Deny from all
        </IfVersion>
</Directory>

<Directory /var/lib/roundcube/logs>
        Options -FollowSymLinks
        AllowOverride None
        <IfVersion >= 2.3>
          Require all denied
        </IfVersion> 
        <IfVersion < 2.3>
          Order allow,deny
          Deny from all
        </IfVersion>
</Directory>

strace:

execve("./a2n", ["./a2n", "-f", "/etc/apache2/conf-available/roun"...], 0x7fffffffe5a0 /* 21 vars */) = 0
brk(NULL)                               = 0x5555558aa000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
access("/etc/ld.so.preload", R_OK)      = 0
openat(AT_FDCWD, "/etc/ld.so.preload", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=41, ...}) = 0
mmap(NULL, 41, PROT_READ|PROT_WRITE, MAP_PRIVATE, 3, 0) = 0x7ffff7ff6000
close(3)                                = 0
openat(AT_FDCWD, "/usr/lib/x86_64-linux-gnu/libeatmydata.so", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\320\7\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=10080, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7ffff7ff4000
mmap(NULL, 2105384, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff7bd2000
mprotect(0x7ffff7bd3000, 2097152, PROT_NONE) = 0
mmap(0x7ffff7dd3000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1000) = 0x7ffff7dd3000
close(3)                                = 0
munmap(0x7ffff7ff6000, 41)              = 0
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=45800, ...}) = 0
mmap(NULL, 45800, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7ffff7fe8000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libz.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\220\37\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=116960, ...}) = 0
mmap(NULL, 2212016, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff79b5000
mprotect(0x7ffff79d1000, 2093056, PROT_NONE) = 0
mmap(0x7ffff7bd0000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b000) = 0x7ffff7bd0000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200\272\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=1700792, ...}) = 0
mmap(NULL, 3789144, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff7617000
mprotect(0x7ffff77b4000, 2093056, PROT_NONE) = 0
mmap(0x7ffff79b3000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19c000) = 0x7ffff79b3000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libexpat.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0@8\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=202880, ...}) = 0
mmap(NULL, 2298016, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff73e5000
mprotect(0x7ffff7414000, 2097152, PROT_NONE) = 0
mmap(0x7ffff7614000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2f000) = 0x7ffff7614000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/librt.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\0\"\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=31680, ...}) = 0
mmap(NULL, 2128864, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff71dd000
mprotect(0x7ffff71e4000, 2093056, PROT_NONE) = 0
mmap(0x7ffff73e3000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6000) = 0x7ffff73e3000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\r\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=39208, ...}) = 0
mmap(NULL, 2322976, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff6fa5000
mprotect(0x7ffff6fae000, 2093056, PROT_NONE) = 0
mmap(0x7ffff71ad000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x8000) = 0x7ffff71ad000
mmap(0x7ffff71af000, 184864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff71af000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0000b\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=144976, ...}) = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7ffff7fe6000
mmap(NULL, 2221184, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff6d86000
mprotect(0x7ffff6da0000, 2093056, PROT_NONE) = 0
mmap(0x7ffff6f9f000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x19000) = 0x7ffff6f9f000
mmap(0x7ffff6fa1000, 13440, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff6fa1000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0P\16\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14560, ...}) = 0
mmap(NULL, 2109712, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff6b82000
mprotect(0x7ffff6b85000, 2093056, PROT_NONE) = 0
mmap(0x7ffff6d84000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7ffff6d84000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\3\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\260\34\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=2030544, ...}) = 0
mmap(NULL, 4131552, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7ffff6791000
mprotect(0x7ffff6978000, 2097152, PROT_NONE) = 0
mmap(0x7ffff6b78000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1e7000) = 0x7ffff6b78000
mmap(0x7ffff6b7e000, 15072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7ffff6b7e000
close(3)                                = 0
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7ffff7fe4000
arch_prctl(ARCH_SET_FS, 0x7ffff7fe4c00) = 0
mprotect(0x7ffff6b78000, 16384, PROT_READ) = 0
mprotect(0x7ffff6d84000, 4096, PROT_READ) = 0
mprotect(0x7ffff6f9f000, 4096, PROT_READ) = 0
mprotect(0x7ffff71ad000, 4096, PROT_READ) = 0
mprotect(0x7ffff73e3000, 4096, PROT_READ) = 0
mprotect(0x7ffff7614000, 8192, PROT_READ) = 0
mprotect(0x7ffff79b3000, 4096, PROT_READ) = 0
mprotect(0x7ffff7bd0000, 4096, PROT_READ) = 0
mprotect(0x7ffff7dd3000, 4096, PROT_READ) = 0
mprotect(0x555555898000, 24576, PROT_READ) = 0
mprotect(0x7ffff7ffc000, 4096, PROT_READ) = 0
munmap(0x7ffff7fe8000, 45800)           = 0
set_tid_address(0x7ffff7fe4ed0)         = 4765
set_robust_list(0x7ffff7fe4ee0, 24)     = 0
rt_sigaction(SIGRTMIN, {sa_handler=0x7ffff6d8bcb0, sa_mask=[], sa_flags=SA_RESTORER|SA_SIGINFO, sa_restorer=0x7ffff6d98890}, NULL, 8) = 0
rt_sigaction(SIGRT_1, {sa_handler=0x7ffff6d8bd50, sa_mask=[], sa_flags=SA_RESTORER|SA_RESTART|SA_SIGINFO, sa_restorer=0x7ffff6d98890}, NULL, 8) = 0
rt_sigprocmask(SIG_UNBLOCK, [RTMIN RT_1], NULL, 8) = 0
prlimit64(0, RLIMIT_STACK, NULL, {rlim_cur=8192*1024, rlim_max=RLIM64_INFINITY}) = 0
futex(0x7ffff6d850c8, FUTEX_WAKE_PRIVATE, 2147483647) = 0
brk(NULL)                               = 0x5555558aa000
brk(0x5555558cb000)                     = 0x5555558cb000
brk(0x5555558ed000)                     = 0x5555558ed000
brk(0x55555590f000)                     = 0x55555590f000
lstat("/etc", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/apache2", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/apache2/conf-available", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/apache2/conf-available/roundcube.conf", {st_mode=S_IFLNK|0777, st_size=26, ...}) = 0
readlink("/etc/apache2/conf-available/roundcube.conf", "/etc/roundcube/apache.conf", 4095) = 26
lstat("/etc", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/roundcube", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/roundcube/apache.conf", {st_mode=S_IFREG|0644, st_size=1240, ...}) = 0
lstat("/etc", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/roundcube", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat("/etc/roundcube/apache.conf", {st_mode=S_IFREG|0644, st_size=1240, ...}) = 0
--- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x558aeb68} ---
+++ killed by SIGSEGV (core dumped) +++