Mercurial > vim
view src/beval.c @ 33664:06b59278bfcf v9.0.2070
patch 9.0.2070: [security] disallow setting env in restricted mode
Commit: https://github.com/vim/vim/commit/6b89dd6a7257a1e2e9c7ea070b407bc4674a5118
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Oct 26 22:14:17 2023 +0200
patch 9.0.2070: [security] disallow setting env in restricted mode
Problem: [security] disallow setting env in restricted mode
Solution: Setting environment variables in restricted mode could
potentially be used to execute shell commands. Disallow this.
restricted mode: disable allow setting of environment variables
Setting environment variables in restricted mode, may have some unwanted
consequences. So, for example by setting $GCONV_PATH in restricted mode
and then calling the iconv() function, one may be able to execute some
unwanted payload, because the `iconv_open()` function internally uses
the `$GCONV_PATH` variable to find its conversion data.
So let's disable setting environment variables, even so this is no
complete protection, since we are not clearing the existing environment.
I tried a few ways but wasn't successful :(
One could also argue to disable the iconv() function completely in
restricted mode, but who knows what other API functions can be
influenced by setting some other unrelated environment variables.
So let's leave it as it is currently.
closes: #13394
See: https://huntr.com/bounties/b0a2eda1-459c-4e36-98e6-0cc7d7faccfe/
Signed-off-by: Christian Brabandt <cb@256bit.org>
author | Christian Brabandt <cb@256bit.org> |
---|---|
date | Thu, 26 Oct 2023 22:30:03 +0200 |
parents | 8fc442c731ca |
children |
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/* vi:set ts=8 sts=4 sw=4 noet: * * VIM - Vi IMproved by Bram Moolenaar * Visual Workshop integration by Gordon Prieur * * 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. */ #include "vim.h" #if defined(FEAT_BEVAL) || defined(FEAT_PROP_POPUP) || defined(PROTO) /* * Find text under the mouse position "row" / "col". * If "getword" is TRUE the returned text in "*textp" is not the whole line but * the relevant word in allocated memory. * Return OK if found. * Return FAIL if not found, no text at the mouse position. */ int find_word_under_cursor( int mouserow, int mousecol, int getword, int flags, // flags for find_ident_at_pos() win_T **winp, // can be NULL linenr_T *lnump, // can be NULL char_u **textp, int *colp, // column where mouse hovers, can be NULL int *startcolp) // column where text starts, can be NULL { int row = mouserow; int col = mousecol; int scol; win_T *wp; char_u *lbuf; linenr_T lnum; *textp = NULL; wp = mouse_find_win(&row, &col, FAIL_POPUP); if (wp == NULL || row < 0 || row >= wp->w_height || col >= wp->w_width) return FAIL; // Found a window and the cursor is in the text. Now find the line // number. if (mouse_comp_pos(wp, &row, &col, &lnum, NULL)) return FAIL; // position is below the last line // Not past end of the file. lbuf = ml_get_buf(wp->w_buffer, lnum, FALSE); if (col > win_linetabsize(wp, lnum, lbuf, (colnr_T)MAXCOL)) return FAIL; // past end of line // Not past end of line. if (getword) { // For Netbeans we get the relevant part of the line // instead of the whole line. int len; pos_T *spos = NULL, *epos = NULL; if (VIsual_active) { if (LT_POS(VIsual, curwin->w_cursor)) { spos = &VIsual; epos = &curwin->w_cursor; } else { spos = &curwin->w_cursor; epos = &VIsual; } } col = vcol2col(wp, lnum, col, NULL); scol = col; if (VIsual_active && wp->w_buffer == curwin->w_buffer && (lnum == spos->lnum ? col >= (int)spos->col : lnum > spos->lnum) && (lnum == epos->lnum ? col <= (int)epos->col : lnum < epos->lnum)) { // Visual mode and pointing to the line with the // Visual selection: return selected text, with a // maximum of one line. if (spos->lnum != epos->lnum || spos->col == epos->col) return FAIL; lbuf = ml_get_buf(curwin->w_buffer, VIsual.lnum, FALSE); len = epos->col - spos->col; if (*p_sel != 'e') len += mb_ptr2len(lbuf + epos->col); lbuf = vim_strnsave(lbuf + spos->col, len); lnum = spos->lnum; col = spos->col; scol = col; } else { // Find the word under the cursor. ++emsg_off; len = find_ident_at_pos(wp, lnum, (colnr_T)col, &lbuf, &scol, flags); --emsg_off; if (len == 0) return FAIL; lbuf = vim_strnsave(lbuf, len); } } else scol = col; if (winp != NULL) *winp = wp; if (lnump != NULL) *lnump = lnum; *textp = lbuf; if (colp != NULL) *colp = col; if (startcolp != NULL) *startcolp = scol; return OK; } #endif #if defined(FEAT_BEVAL) || defined(PROTO) /* * Get the text and position to be evaluated for "beval". * If "getword" is TRUE the returned text is not the whole line but the * relevant word in allocated memory. * Returns OK or FAIL. */ int get_beval_info( BalloonEval *beval, int getword, win_T **winp, linenr_T *lnump, char_u **textp, int *colp) { int row = mouse_row; int col = mouse_col; # ifdef FEAT_BEVAL_GUI if (gui.in_use) { row = Y_2_ROW(beval->y); col = X_2_COL(beval->x); } # endif if (find_word_under_cursor(row, col, getword, FIND_IDENT + FIND_STRING + FIND_EVAL, winp, lnump, textp, colp, NULL) == OK) { # ifdef FEAT_VARTABS vim_free(beval->vts); beval->vts = tabstop_copy((*winp)->w_buffer->b_p_vts_array); if ((*winp)->w_buffer->b_p_vts_array != NULL && beval->vts == NULL) { if (getword) vim_free(*textp); return FAIL; } # endif beval->ts = (*winp)->w_buffer->b_p_ts; return OK; } return FAIL; } /* * Show a balloon with "mesg" or "list". * Hide the balloon when both are NULL. */ void post_balloon(BalloonEval *beval UNUSED, char_u *mesg, list_T *list UNUSED) { # ifdef FEAT_BEVAL_TERM # ifdef FEAT_GUI if (!gui.in_use) # endif ui_post_balloon(mesg, list); # endif # ifdef FEAT_BEVAL_GUI if (gui.in_use) // GUI can't handle a list gui_mch_post_balloon(beval, mesg); # endif } /* * Returns TRUE if the balloon eval has been enabled: * 'ballooneval' for the GUI and 'balloonevalterm' for the terminal. * Also checks if the screen isn't scrolled up. */ int can_use_beval(void) { return (0 #ifdef FEAT_BEVAL_GUI || (gui.in_use && p_beval) #endif #ifdef FEAT_BEVAL_TERM || ( # ifdef FEAT_GUI !gui.in_use && # endif p_bevalterm) #endif ) && msg_scrolled == 0; } # ifdef FEAT_EVAL /* * Evaluate the expression 'bexpr' and set the text in the balloon 'beval'. */ static void bexpr_eval( BalloonEval *beval, char_u *bexpr, win_T *wp, linenr_T lnum, int col, char_u *text) { win_T *cw; long winnr = 0; buf_T *save_curbuf; int use_sandbox; static char_u *result = NULL; size_t len; sctx_T save_sctx = current_sctx; // Convert window pointer to number. for (cw = firstwin; cw != wp; cw = cw->w_next) ++winnr; set_vim_var_nr(VV_BEVAL_BUFNR, (long)wp->w_buffer->b_fnum); set_vim_var_nr(VV_BEVAL_WINNR, winnr); set_vim_var_nr(VV_BEVAL_WINID, wp->w_id); set_vim_var_nr(VV_BEVAL_LNUM, (long)lnum); set_vim_var_nr(VV_BEVAL_COL, (long)(col + 1)); set_vim_var_string(VV_BEVAL_TEXT, text, -1); vim_free(text); /* * Temporarily change the curbuf, so that we can determine whether * the buffer-local balloonexpr option was set insecurely. */ save_curbuf = curbuf; curbuf = wp->w_buffer; use_sandbox = was_set_insecurely((char_u *)"balloonexpr", *curbuf->b_p_bexpr == NUL ? 0 : OPT_LOCAL); curbuf = save_curbuf; if (use_sandbox) ++sandbox; ++textlock; if (bexpr == p_bexpr) { sctx_T *sp = get_option_sctx("balloonexpr"); if (sp != NULL) current_sctx = *sp; } else current_sctx = curbuf->b_p_script_ctx[BV_BEXPR]; vim_free(result); result = eval_to_string(bexpr, TRUE, TRUE); // Remove one trailing newline, it is added when the result was a // list and it's hardly ever useful. If the user really wants a // trailing newline he can add two and one remains. if (result != NULL) { len = STRLEN(result); if (len > 0 && result[len - 1] == NL) result[len - 1] = NUL; } if (use_sandbox) --sandbox; --textlock; current_sctx = save_sctx; set_vim_var_string(VV_BEVAL_TEXT, NULL, -1); if (result != NULL && result[0] != NUL) post_balloon(beval, result, NULL); // The 'balloonexpr' evaluation may show something on the screen // that requires a screen update. if (must_redraw) redraw_after_callback(FALSE, FALSE); } # endif /* * Common code, invoked when the mouse is resting for a moment. */ void general_beval_cb(BalloonEval *beval, int state UNUSED) { #ifdef FEAT_EVAL win_T *wp; int col; linenr_T lnum; char_u *text; char_u *bexpr; #endif static int recursive = FALSE; // Don't do anything when 'ballooneval' is off, messages scrolled the // windows up or we have no beval area. if (!can_use_beval() || beval == NULL) return; // Don't do this recursively. Happens when the expression evaluation // takes a long time and invokes something that checks for CTRL-C typed. if (recursive) return; recursive = TRUE; #ifdef FEAT_EVAL if (get_beval_info(beval, TRUE, &wp, &lnum, &text, &col) == OK) { bexpr = (*wp->w_buffer->b_p_bexpr == NUL) ? p_bexpr : wp->w_buffer->b_p_bexpr; if (*bexpr != NUL) { bexpr_eval(beval, bexpr, wp, lnum, col, text); recursive = FALSE; return; } } #endif #ifdef FEAT_NETBEANS_INTG if (bevalServers & BEVAL_NETBEANS) netbeans_beval_cb(beval, state); #endif recursive = FALSE; } #endif