hush: fix umask: umask(022) was setting umask(755)

Based on the patch by Rich Felker <dalias@libc.org>

function                                             old     new   delta
builtin_umask                                        121     161     +40
umaskcmd                                             318     279     -39

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 21 insertions, 25 deletions

diff --git a/shell/ash.c b/shell/ash.c
index b34dcc149..2669157bc 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -12814,7 +12814,7 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 }
 
 static int FAST_FUNC
-umaskcmd(int argc UNUSED_PARAM, char **argv)
+umaskcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 {
         static const char permuser[3] ALIGN1 = "ugo";
         static const char permmode[3] ALIGN1 = "rwx";
@@ -12824,9 +12824,6 @@ umaskcmd(int argc UNUSED_PARAM, char **argv)
                 S_IROTH, S_IWOTH, S_IXOTH
         };
 
-        /* TODO: use bb_parse_mode() instead */
-
-        char *ap;
         mode_t mask;
         int i;
         int symbolic_mode = 0;
@@ -12840,8 +12837,7 @@ umaskcmd(int argc UNUSED_PARAM, char **argv)
         umask(mask);
         INT_ON;
 
-        ap = *argptr;
-        if (ap == NULL) {
+        if (*argptr == NULL) {
                 if (symbolic_mode) {
                         char buf[18];
                         char *p = buf;
@@ -12858,27 +12854,23 @@ umaskcmd(int argc UNUSED_PARAM, char **argv)
                                 }
                                 *p++ = ',';
                         }
-                        *--p = 0;
+                        *--p = '\0';
                         puts(buf);
                 } else {
                         out1fmt("%.4o\n", mask);
                 }
         } else {
-                if (isdigit((unsigned char) *ap)) {
-                        mask = 0;
-                        do {
-                                if (*ap >= '8' || *ap < '0')
-                                        ash_msg_and_raise_error(msg_illnum, argv[1]);
-                                mask = (mask << 3) + (*ap - '0');
-                        } while (*++ap != '\0');
-                        umask(mask);
-                } else {
-                        mask = ~mask & 0777;
-                        if (!bb_parse_mode(ap, &mask)) {
-                                ash_msg_and_raise_error("illegal mode: %s", ap);
-                        }
-                        umask(~mask & 0777);
-                }
+                char *modestr = *argptr;
+                /* numeric umasks are taken as-is */
+                /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
+                if (!isdigit(modestr[0]))
+                        mask ^= 0777;
+                if (!bb_parse_mode(modestr, &mask) || (unsigned)mask > 0777) {
+                        ash_msg_and_raise_error("illegal mode: %s", modestr);
+                }
+                if (!isdigit(modestr[0]))
+                        mask ^= 0777;
+                umask(mask);
         }
         return 0;
 }
diff --git a/shell/hush.c b/shell/hush.c
index 752080a64..8b8d5fc8b 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -8970,10 +8970,14 @@ static int FAST_FUNC builtin_umask(char **argv)
         if (argv[0]) {
                 mode_t old_mask = mask;
 
-                mask ^= 0777;
+                /* numeric umasks are taken as-is */
+                /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
+                if (!isdigit(argv[0][0]))
+                        mask ^= 0777;
                 rc = bb_parse_mode(argv[0], &mask);
-                mask ^= 0777;
-                if (rc == 0) {
+                if (!isdigit(argv[0][0]))
+                        mask ^= 0777;
+                if (rc == 0 || (unsigned)mask > 0777) {
                         mask = old_mask;
                         /* bash messages:
                          * bash: umask: 'q': invalid symbolic mode operator