opendoas

my fork of doas with custom prompt
git clone git://git.kocotian.pl/opendoas.git
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commit dd136587ed181ac3a6eb5c3fcdfa2f99f42e020d
parent 9a9495d672fb426010a6b52d637c30a0dbeb619f
Author: tedu <tedu>
Date:   Mon, 10 Jun 2019 18:11:27 +0000

use getpwuid_r to avoid problems with hidden static storage. ok deraadt lteo martijn

Diffstat:
Mdoas.c | 93+++++++++++++++++++++++++++++++++++++++++++++++++------------------------------
1 file changed, 58 insertions(+), 35 deletions(-)

diff --git a/doas.c b/doas.c @@ -260,13 +260,19 @@ main(int argc, char **argv) const char *cmd; char cmdline[LINE_MAX]; char myname[_PW_NAME_LEN + 1]; - struct passwd *pw; +#ifdef __OpenBSD__ + char mypwbuf[_PW_BUF_LEN], targpwbuf[_PW_BUF_LEN]; +#else + char *mypwbuf = NULL, *targpwbuf = NULL; +#endif + struct passwd mypwstore, targpwstore; + struct passwd *mypw, *targpw; const struct rule *rule; uid_t uid; uid_t target = 0; gid_t groups[NGROUPS_MAX + 1]; int ngroups; - int i, ch; + int i, ch, rv; int sflag = 0; int nflag = 0; char cwdpath[PATH_MAX]; @@ -333,10 +339,23 @@ main(int argc, char **argv) } else if ((!sflag && !argc) || (sflag && argc)) usage(); - pw = getpwuid(uid); - if (!pw) - err(1, "getpwuid failed"); - if (strlcpy(myname, pw->pw_name, sizeof(myname)) >= sizeof(myname)) +#ifdef __OpenBSD__ + rv = getpwuid_r(uid, &mypwstore, mypwbuf, sizeof(mypwbuf), &mypw); + if (rv != 0 || mypw == NULL) + err(1, "getpwuid_r failed"); +#else + for (size_t sz = 1024; sz <= 16*1024; sz *= 2) { + mypwbuf = reallocarray(mypwbuf, sz, sizeof (char)); + if (mypwbuf == NULL) + errx(1, "can't allocate mypwbuf"); + rv = getpwuid_r(uid, &mypwstore, mypwbuf, sz, &mypw); + if (rv != ERANGE) + break; + } + if (rv != 0 || mypw == NULL) + err(1, "getpwuid_r failed"); +#endif + if (strlcpy(myname, mypw->pw_name, sizeof(myname)) >= sizeof(myname)) errx(1, "pw_name too long"); ngroups = getgroups(NGROUPS_MAX, groups); if (ngroups == -1) @@ -346,7 +365,7 @@ main(int argc, char **argv) if (sflag) { sh = getenv("SHELL"); if (sh == NULL || *sh == '\0') { - shargv[0] = strdup(pw->pw_shell); + shargv[0] = strdup(mypw->pw_shell); if (shargv[0] == NULL) err(1, NULL); } else @@ -383,57 +402,61 @@ main(int argc, char **argv) errc(1, EPERM, NULL); } -#if defined(__OpenBSD__) +#if defined(__OpenBSD__) || defined(USE_SHADOW) if (!(rule->options & NOPASS)) { if (nflag) errx(1, "Authorization required"); +# ifdef __OpenBSD__ authuser(myname, login_style, rule->options & PERSIST); +# else + shadowauth(myname, rule->options & PERSIST); +# endif } +# ifdef __OpenBSD__ if (pledge("stdio rpath getpw exec id", NULL) == -1) err(1, "pledge"); +# endif - pw = getpwuid(target); - if (!pw) - errx(1, "no passwd entry for target"); - -#elif defined(USE_SHADOW) +#elif !defined(USE_PAM) + (void) nflag; if (!(rule->options & NOPASS)) { - if (nflag) - errx(1, "Authorization required"); - - shadowauth(myname, rule->options & PERSIST); + errx(1, "Authorization required"); } +#endif /* !(__OpenBSD__ || USE_SHADOW) && !USE_PAM */ - pw = getpwuid(target); - if (!pw) - errx(1, "no passwd entry for target"); - -#elif defined(USE_PAM) - pw = getpwuid(target); - if (!pw) +#ifdef __OpenBSD__ + rv = getpwuid_r(target, &targpwstore, targpwbuf, sizeof(targpwbuf), &targpw); + if (rv != 0 || targpw == NULL) errx(1, "no passwd entry for target"); - - pamauth(pw->pw_name, myname, !nflag, rule->options & NOPASS, - rule->options & PERSIST); - #else - (void) nflag; - if (!(rule->options & NOPASS)) { - errx(1, "Authorization required"); + for (size_t sz = 1024; sz <= 16*1024; sz *= 2) { + targpwbuf = reallocarray(targpwbuf, sz, sizeof (char)); + if (targpwbuf == NULL) + errx(1, "can't allocate targpwbuf"); + rv = getpwuid_r(target, &targpwstore, targpwbuf, sz, &targpw); + if (rv != ERANGE) + break; } + if (rv != 0 || targpw == NULL) + err(1, "getpwuid_r failed"); +#endif + +#if defined(USE_PAM) + pamauth(targpw->pw_name, myname, !nflag, rule->options & NOPASS, + rule->options & PERSIST); #endif #ifdef HAVE_SETUSERCONTEXT - if (setusercontext(NULL, pw, target, LOGIN_SETGROUP | + if (setusercontext(NULL, targpw, target, LOGIN_SETGROUP | LOGIN_SETPRIORITY | LOGIN_SETRESOURCES | LOGIN_SETUMASK | LOGIN_SETUSER) != 0) errx(1, "failed to set user context for target"); #else - if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) + if (setresgid(targpw->pw_gid, targpw->pw_gid, targpw->pw_gid) != 0) err(1, "setresgid"); - if (initgroups(pw->pw_name, pw->pw_gid) != 0) + if (initgroups(targpw->pw_name, targpw->pw_gid) != 0) err(1, "initgroups"); if (setresuid(target, target, target) != 0) err(1, "setresuid"); @@ -455,7 +478,7 @@ main(int argc, char **argv) #endif syslog(LOG_AUTHPRIV | LOG_INFO, "%s ran command %s as %s from %s", - myname, cmdline, pw->pw_name, cwd); + myname, cmdline, targpw->pw_name, cwd); envp = prepenv(rule);