Previously, the number of command line args was not checked for
cygwin process. Due to this, segmentation fault was caused if too
many command line args are specified.
https://cygwin.com/pipermail/cygwin/2023-August/254333.html
Since char *argv[argc + 1] is placed on the stack in dll_crt0_1(),
STATUS_STACK_OVERFLOW occurs if the stack does not have enough
space.
With this patch, char *argv[] is placed in heap instead of stack
and ARG_MAX is increased from 32000 to
2097152 which is default
value of Linux. The argument length is also compared with ARG_MAX
and spawnve() returns E2BIG if it is too long.
Reported-by: Ed Morton
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
a change to an element of argv[] it does not affect Cygwin's argv.
Changing the the contents of what argv[n] points to will still
affect Cygwin. This is similar (but not exactly like) Linux. */
- char *newargv[__argc + 1];
- char **nav = newargv;
- char **oav = __argv;
- while ((*nav++ = *oav++) != NULL)
- continue;
+ char **newargv = (char **) malloc ((__argc + 1) * sizeof (char *));
+ memcpy (newargv, __argv, (__argc + 1) * sizeof (char *));
/* Handle any signals which may have arrived */
sig_dispatch_pending (false);
_my_tls.call_signal_handler ();
application provided path strings we handle. */
#define NT_MAX_PATH 32768
+/* CYG_ARG_MAX is the maximum total length of command line args.
+ The value 2097152 is the default ARG_MAX value in Linux. */
+#define CYG_ARG_MAX 2097152
+
/* This definition allows to define wide char strings using macros as
parameters. See the definition of __CONCAT in newlib's sys/cdefs.h
and accompanying comment. */
- For the time being, disable creating special files using mknod/mkfifo
on NFS.
Addresses: https://cygwin.com/pipermail/cygwin/2023-August/254266.html
+
+- Fix segfault when too many command line args are specified.
+ Addresses: https://cygwin.com/pipermail/cygwin/2023-August/254333.html
We need to quote any argument that has whitespace or embedded "'s. */
int ac;
+ size_t arg_len = 0;
for (ac = 0; argv[ac]; ac++)
- /* nothing */;
+ arg_len += strlen (argv[ac]) + 1;
int err;
const char *ext;
__leave;
}
set (chtype, real_path.iscygexec ());
+ if (iscygwin () && arg_len > (size_t) sysconf (_SC_ARG_MAX))
+ {
+ set_errno (E2BIG);
+ res = -1;
+ __leave;
+ }
__stdin = in__stdin;
__stdout = in__stdout;
record_children ();
};
} sca[] =
{
- {cons, {c:ARG_MAX}}, /* 0, _SC_ARG_MAX */
+ {cons, {c:CYG_ARG_MAX}}, /* 0, _SC_ARG_MAX */
{cons, {c:CHILD_MAX}}, /* 1, _SC_CHILD_MAX */
{cons, {c:CLOCKS_PER_SEC}}, /* 2, _SC_CLK_TCK */
{cons, {c:NGROUPS_MAX}}, /* 3, _SC_NGROUPS_MAX */