Mercurial > vim
view src/pty.c @ 33811:06219b3bdaf3 v9.0.2121
patch 9.0.2121: [security]: use-after-free in ex_substitute
Commit: https://github.com/vim/vim/commit/26c11c56888d01e298cd8044caf860f3c26f57bb
Author: Christian Brabandt <cb@256bit.org>
Date: Wed Nov 22 21:26:41 2023 +0100
patch 9.0.2121: [security]: use-after-free in ex_substitute
Problem: [security]: use-after-free in ex_substitute
Solution: always allocate memory
closes: #13552
A recursive :substitute command could cause a heap-use-after free in Vim
(CVE-2023-48706).
The whole reproducible test is a bit tricky, I can only reproduce this
reliably when no previous substitution command has been used yet
(which is the reason, the test needs to run as first one in the
test_substitute.vim file) and as a combination of the `:~` command
together with a :s command that contains the special substitution atom `~\=`
which will make use of a sub-replace special atom and calls a vim script
function.
There was a comment in the existing :s code, that already makes the
`sub` variable allocate memory so that a recursive :s call won't be able
to cause any issues here, so this was known as a potential problem
already. But for the current test-case that one does not work, because
the substitution does not start with `\=` but with `~\=` (and since
there does not yet exist a previous substitution atom, Vim will simply
increment the `sub` pointer (which then was not allocated dynamically)
and later one happily use a sub-replace special expression (which could
then free the `sub` var).
The following commit fixes this, by making the sub var always using
allocated memory, which also means we need to free the pointer whenever
we leave the function. Since sub is now always an allocated variable,
we also do no longer need the sub_copy variable anymore, since this one
was used to indicated when sub pointed to allocated memory (and had
therefore to be freed on exit) and when not.
Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-c8qm-x72m-q53q
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Wed, 22 Nov 2023 22:15:05 +0100 |
parents | 695b50472e85 |
children | 7c30841c60a0 |
line wrap: on
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/* vi:set ts=8 sts=4 sw=4 noet: * * VIM - Vi IMproved by Bram Moolenaar * * Do ":help uganda" in Vim to read copying and usage conditions. * Do ":help credits" in Vim to see a list of people who contributed. * See README.txt for an overview of the Vim source code. */ /* * The stuff in this file mostly comes from the "screen" program. * Included with permission from Juergen Weigert. * Copied from "pty.c". "putenv.c" was used for putenv() in misc2.c. * * It has been modified to work better with Vim. * The parts that are not used in Vim have been deleted. * See the "screen" sources for the complete stuff. * * This specific version is distributed under the Vim license (attribution by * Juergen Weigert), the GPL applies to the original version, see the * copyright notice below. */ // Copyright (c) 1993 // Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de) // Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de) // Copyright (c) 1987 Oliver Laumann // // This program is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 2, or (at your option) // any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program (see the file COPYING); if not, write to the // Free Software Foundation, Inc., // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA #include "vim.h" #if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL) #include <signal.h> #ifdef HAVE_SYS_IOCTL_H # include <sys/ioctl.h> #endif #if HAVE_STROPTS_H # include <sys/types.h> # ifdef sinix # define buf_T __system_buf_t__ # endif # include <stropts.h> # ifdef sinix # undef buf_T # endif # ifdef SUN_SYSTEM # include <sys/conf.h> # if defined(HAVE_SYS_PTMS_H) && defined(HAVE_SVR4_PTYS) # include <sys/ptms.h> # endif # endif #endif #ifdef HAVE_UNISTD_H # include <unistd.h> #endif #if HAVE_TERMIO_H # include <termio.h> #else # ifdef HAVE_TERMIOS_H # include <termios.h> # endif #endif #if HAVE_SYS_STREAM_H # include <sys/stream.h> #endif #if HAVE_SYS_PTEM_H # include <sys/ptem.h> #endif #if !defined(SUN_SYSTEM) && !defined(VMS) # include <sys/ioctl.h> #endif #if defined(SUN_SYSTEM) && defined(LOCKPTY) && !defined(TIOCEXCL) # include <sys/ttold.h> #endif #ifdef ISC # include <sys/tty.h> # include <sys/sioctl.h> # include <sys/pty.h> #endif #ifdef sgi # include <sys/sysmacros.h> #endif #if defined(_INCLUDE_HPUX_SOURCE) && !defined(hpux) # define hpux #endif /* * if no PTYRANGE[01] is in the config file, we pick a default */ #ifndef PTYRANGE0 # define PTYRANGE0 "qprs" #endif #ifndef PTYRANGE1 # define PTYRANGE1 "0123456789abcdef" #endif // SVR4 pseudo ttys don't seem to work with SCO-5 #ifdef M_UNIX # undef HAVE_SVR4_PTYS #endif /* * Open all ptys with O_NOCTTY, just to be on the safe side. */ #ifndef O_NOCTTY # define O_NOCTTY 0 #endif #if defined(HAVE_SVR4_PTYS) || defined(HAVE_POSIX_OPENPT) // These should be in stdlib.h, but it depends on _XOPEN_SOURCE. char *ptsname(int); int unlockpt(int); int grantpt(int); int posix_openpt(int flags); #endif static void initmaster(int f UNUSED) { #ifndef VMS # ifdef POSIX tcflush(f, TCIOFLUSH); # else # ifdef TIOCFLUSH (void)ioctl(f, TIOCFLUSH, (char *) 0); # endif # endif # ifdef LOCKPTY (void)ioctl(f, TIOCEXCL, (char *) 0); # endif #endif } /* * This causes a hang on some systems, but is required for a properly working * pty on others. Needs to be tuned... */ int setup_slavepty(int fd) { if (fd < 0) return 0; #if defined(I_PUSH) && defined(HAVE_SVR4_PTYS) && !defined(sgi) \ && !defined(linux) && !defined(__osf__) && !defined(M_UNIX) # if defined(HAVE_SYS_PTEM_H) || defined(hpux) if (ioctl(fd, I_PUSH, "ptem") != 0) return -1; # endif if (ioctl(fd, I_PUSH, "ldterm") != 0) return -1; # ifdef SUN_SYSTEM if (ioctl(fd, I_PUSH, "ttcompat") != 0) return -1; # endif #endif return 0; } #if defined(HAVE_POSIX_OPENPT) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; char *m; sighandler_T sigcld; static char TtyName[32]; // used for opening a new pty-pair if ((f = posix_openpt(O_RDWR | O_NOCTTY | O_EXTRA)) == -1) return -1; // SIGCHLD set to SIG_DFL for grantpt() because it fork()s and // exec()s pt_chmod sigcld = mch_signal(SIGCHLD, SIG_DFL); if ((m = ptsname(f)) == NULL || grantpt(f) || unlockpt(f)) { mch_signal(SIGCHLD, sigcld); close(f); return -1; } mch_signal(SIGCHLD, sigcld); vim_strncpy((char_u *)TtyName, (char_u *)m, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(OSX) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; static char TtyName[32]; if ((f = open_controlling_pty(TtyName)) < 0) return -1; initmaster(f); *ttyn = TtyName; return f; } #endif #if (defined(sequent) || defined(_SEQUENT_)) && defined(HAVE_GETPSEUDOTTY) \ && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { char *m, *s; int f; // used for opening a new pty-pair: static char PtyName[32]; static char TtyName[32]; if ((f = getpseudotty(&s, &m)) < 0) return -1; #ifdef _SEQUENT_ fvhangup(s); #endif vim_strncpy((char_u *)PtyName, (char_u *)m, sizeof(PtyName) - 1); vim_strncpy((char_u *)TtyName, (char_u *)s, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(MIPS) && defined(HAVE_DEV_PTC) && !defined(PTY_DONE) #define PTY_DONE int mch_openpty(char **ttyn) { int f; stat_T buf; // used for opening a new pty-pair: static char TtyName[32]; if ((f = open("/dev/ptc", O_RDWR | O_NOCTTY | O_NONBLOCK | O_EXTRA, 0)) < 0) return -1; if (mch_fstat(f, &buf) < 0) { close(f); return -1; } sprintf(TtyName, "/dev/ttyq%d", minor(buf.st_rdev)); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(HAVE_SVR4_PTYS) && !defined(PTY_DONE) && !defined(hpux) \ && !(defined(MACOS_X) && !defined(MAC_OS_X_VERSION_10_6)) // NOTE: Even though HPUX can have /dev/ptmx, the code below doesn't work! // Same for Mac OS X Leopard (10.5). #define PTY_DONE int mch_openpty(char **ttyn) { int f; char *m; sighandler_T sigcld; // used for opening a new pty-pair: static char TtyName[32]; if ((f = open("/dev/ptmx", O_RDWR | O_NOCTTY | O_EXTRA, 0)) == -1) return -1; /* * SIGCHLD set to SIG_DFL for grantpt() because it fork()s and * exec()s pt_chmod */ sigcld = mch_signal(SIGCHLD, SIG_DFL); if ((m = ptsname(f)) == NULL || grantpt(f) || unlockpt(f)) { mch_signal(SIGCHLD, sigcld); close(f); return -1; } mch_signal(SIGCHLD, sigcld); vim_strncpy((char_u *)TtyName, (char_u *)m, sizeof(TtyName) - 1); initmaster(f); *ttyn = TtyName; return f; } #endif #if defined(_AIX) && defined(HAVE_DEV_PTC) && !defined(PTY_DONE) #define PTY_DONE #ifdef _IBMR2 static int aixhack = -1; #endif int mch_openpty(char **ttyn) { int f; // used for opening a new pty-pair: static char TtyName[32]; // a dumb looking loop replaced by mycrofts code: if ((f = open("/dev/ptc", O_RDWR | O_NOCTTY | O_EXTRA)) < 0) return -1; vim_strncpy((char_u *)TtyName, (char_u *)ttyname(f), sizeof(TtyName) - 1); if (geteuid() != ROOT_UID && mch_access(TtyName, R_OK | W_OK)) { close(f); return -1; } initmaster(f); # ifdef _IBMR2 if (aixhack >= 0) close(aixhack); if ((aixhack = open(TtyName, O_RDWR | O_NOCTTY | O_EXTRA, 0)) < 0) { close(f); return -1; } # endif *ttyn = TtyName; return f; } #endif #ifndef PTY_DONE # ifdef hpux static char PtyProto[] = "/dev/ptym/ptyXY"; static char TtyProto[] = "/dev/pty/ttyXY"; # else # ifdef(__HAIKU__) static char PtyProto[] = "/dev/pt/XY"; static char TtyProto[] = "/dev/tt/XY"; # else static char PtyProto[] = "/dev/ptyXY"; static char TtyProto[] = "/dev/ttyXY"; # endif # endif int mch_openpty(char **ttyn) { char *p, *q, *l, *d; int f; // used for opening a new pty-pair: static char PtyName[32]; static char TtyName[32]; strcpy(PtyName, PtyProto); strcpy(TtyName, TtyProto); for (p = PtyName; *p != 'X'; p++) ; for (q = TtyName; *q != 'X'; q++) ; for (l = PTYRANGE0; (*p = *l) != '\0'; l++) { for (d = PTYRANGE1; (p[1] = *d) != '\0'; d++) { if ((f = open(PtyName, O_RDWR | O_NOCTTY | O_EXTRA, 0)) == -1) continue; q[0] = *l; q[1] = *d; if (geteuid() != ROOT_UID && mch_access(TtyName, R_OK | W_OK)) { close(f); continue; } #if defined(SUN_SYSTEM) && defined(TIOCGPGRP) && !defined(SUNOS3) // Hack to ensure that the slave side of the pty is // unused. May not work in anything other than SunOS4.1 { int pgrp; // tcgetpgrp does not work (uses TIOCGETPGRP)! if (ioctl(f, TIOCGPGRP, (char *)&pgrp) != -1 || errno != EIO) { close(f); continue; } } #endif initmaster(f); *ttyn = TtyName; return f; } } return -1; } #endif /* * Call isatty(fd), except for SunOS where it's done differently. */ int mch_isatty(int fd) { # if defined(I_STR) && defined(HAVE_SYS_PTMS_H) && defined(HAVE_SVR4_PTYS) \ && defined(SUN_SYSTEM) // On SunOS, isatty() for /dev/ptmx returns false or sometimes can hang up // in the inner ioctl(), and therefore first determine whether "fd" is a // master device. struct strioctl istr; istr.ic_cmd = ISPTM; istr.ic_timout = 0; istr.ic_dp = NULL; istr.ic_len = 0; if (ioctl(fd, I_STR, &istr) == 0) // Trick: return 2 in order to advice the caller that "fd" is a master // device. cf. src/os_unix.c:get_tty_fd() return 2; # endif return isatty(fd); } #endif // FEAT_GUI || FEAT_JOB_CHANNEL