diff options
Diffstat (limited to 'Src/options.c')
| -rw-r--r-- | Src/options.c | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/Src/options.c b/Src/options.c index 590652ea9..600b649e4 100644 --- a/Src/options.c +++ b/Src/options.c @@ -769,15 +769,32 @@ dosetopt(int optno, int value, int force, char *new_opts) } else if(optno == PRIVILEGED && !value) { /* unsetting PRIVILEGED causes the shell to make itself unprivileged */ #ifdef HAVE_SETUID - setuid(getuid()); - setgid(getgid()); - if (setuid(getuid())) { - zwarn("failed to change user ID: %e", errno); - return -1; - } else if (setgid(getgid())) { + int ignore_err; + errno = 0; + /* + * Set the GID first as if we set the UID to non-privileged it + * might be impossible to restore the GID. + * + * Some OSes (possibly no longer around) have been known to + * fail silently the first time, so we attempt the change twice. + * If it fails we are guaranteed to pick this up the second + * time, so ignore the first time. + * + * Some versions of gcc make it hard to ignore the results the + * first time, hence the following. (These are probably not + * systems that require the doubled calls.) + */ + ignore_err = setgid(getgid()); + (void)ignore_err; + ignore_err = setuid(getuid()); + (void)ignore_err; + if (setgid(getgid())) { zwarn("failed to change group ID: %e", errno); return -1; - } + } else if (setuid(getuid())) { + zwarn("failed to change user ID: %e", errno); + return -1; + } #else zwarn("setuid not available"); return -1; |