Mercurial > vim
view src/proto/window.pro @ 34454:f8fed6c8bb60 v9.1.0143
patch 9.1.0143: [security]: autocmd causes use-after-free in set_curbuf()
Commit: https://github.com/vim/vim/commit/55f8bba73be5f9c3a5a4d0d6c5f56e65f2c7d3fc
Author: Christian Brabandt <cb@256bit.org>
Date: Wed Feb 28 23:32:00 2024 +0100
patch 9.1.0143: [security]: autocmd causes use-after-free in set_curbuf()
Problem: [security]: autocmd cause use-after-free in set_curbuf()
(kawarimidoll)
Solution: check side-effect of BufLeave autocommand, when the number
of windows changed, close windows containing buffers that will
be wiped, if curbuf changed unexpectedly make sure b_nwindows
is decremented otherwise it cannot be wiped
set_curbuf() already makes some efforts to ensure the BufLeave
autocommands do not cause issues. However there are still 2 issues
that are not taken care of:
1) If a BufLeave autocommand opens a new window containing the same
buffer as that is going got be closed in close_buffer() a bit later,
we suddenly have another window open, containing a free'd buffer. So we
must check if the number of windows changed and if it does (and the
current buffer is going to be wiped (according to the 'bufhidden'
setting), let's immediately close all windows containing the current
buffer using close_windows()
2) If a BufLeave autocommand changes our current buffer (displays it in
the current window), buf->b_nwindow will be incremented. As part of
set_curbuf() we will however enter another buffer soon, which means, the
newly created curbuf will have b_nwindows still have set, even so the
buffer is no longer displayed in a window. This causes later problems,
because it will no longer be possible to wipe such a buffer. So just
before entering the final buffer, check if the curbuf changed when
calling the BufLeave autocommand and if it does (and curbuf is still
valid), decrement curbuf->b_nwindows.
Both issues can be verified using the provided test (however the second
issue only because such an impacted buffer won't be wiped, causing
futher issues in later tests).
fixes: #13839
closes: #14104
Signed-off-by: Christian Brabandt <cb@256bit.org>
| author | Christian Brabandt <cb@256bit.org> |
|---|---|
| date | Wed, 28 Feb 2024 23:45:03 +0100 |
| parents | 8b0e390b61fe |
| children | dd8f5311cee5 |
line wrap: on
line source
/* window.c */ int window_layout_locked(enum CMD_index cmd); win_T *prevwin_curwin(void); win_T *swbuf_goto_win_with_buf(buf_T *buf); void do_window(int nchar, long Prenum, int xchar); void get_wincmd_addr_type(char_u *arg, exarg_T *eap); int check_split_disallowed(win_T *wp); int win_split(int size, int flags); int win_splitmove(win_T *wp, int size, int flags); int win_split_ins(int size, int flags, win_T *new_wp, int dir, frame_T *to_flatten); int win_valid_popup(win_T *win); int win_valid(win_T *win); win_T *win_find_by_id(int id); int win_valid_any_tab(win_T *win); int win_count(void); int make_windows(int count, int vertical); void win_move_after(win_T *win1, win_T *win2); void win_equal(win_T *next_curwin, int current, int dir); void leaving_window(win_T *win); void entering_window(win_T *win); void curwin_init(void); void close_windows(buf_T *buf, int keep_curwin); int last_window(void); int one_window(void); int win_close(win_T *win, int free_buf); void snapshot_windows_scroll_size(void); void may_make_initial_scroll_size_snapshot(void); void may_trigger_win_scrolled_resized(void); void win_close_othertab(win_T *win, int free_buf, tabpage_T *tp); void win_free_all(void); win_T *winframe_remove(win_T *win, int *dirp, tabpage_T *tp, frame_T **unflat_altfr); void close_others(int message, int forceit); void unuse_tabpage(tabpage_T *tp); void use_tabpage(tabpage_T *tp); int win_alloc_first(void); win_T *win_alloc_popup_win(void); void win_init_popup_win(win_T *wp, buf_T *buf); void win_init_size(void); void free_tabpage(tabpage_T *tp); int win_new_tabpage(int after); int make_tabpages(int maxcount); int valid_tabpage(tabpage_T *tpc); int valid_tabpage_win(tabpage_T *tpc); void close_tabpage(tabpage_T *tab); tabpage_T *find_tabpage(int n); int tabpage_index(tabpage_T *ftp); void goto_tabpage(int n); void goto_tabpage_tp(tabpage_T *tp, int trigger_enter_autocmds, int trigger_leave_autocmds); int goto_tabpage_lastused(void); void goto_tabpage_win(tabpage_T *tp, win_T *wp); void tabpage_move(int nr); void win_goto(win_T *wp); win_T *win_find_nr(int winnr); tabpage_T *win_find_tabpage(win_T *win); win_T *win_vert_neighbor(tabpage_T *tp, win_T *wp, int up, long count); win_T *win_horz_neighbor(tabpage_T *tp, win_T *wp, int left, long count); void win_enter(win_T *wp, int undo_sync); win_T *buf_jump_open_win(buf_T *buf); win_T *buf_jump_open_tab(buf_T *buf); int win_unlisted(win_T *wp); void win_free_popup(win_T *win); void win_remove(win_T *wp, tabpage_T *tp); int win_alloc_lines(win_T *wp); void win_free_lsize(win_T *wp); void shell_new_rows(void); void shell_new_columns(void); void win_size_save(garray_T *gap); void win_size_restore(garray_T *gap); int win_comp_pos(void); void win_ensure_size(void); void win_setheight(int height); void win_setheight_win(int height, win_T *win); void win_setwidth(int width); void win_setwidth_win(int width, win_T *wp); void win_setminheight(void); void win_setminwidth(void); void win_drag_status_line(win_T *dragwin, int offset); void win_drag_vsep_line(win_T *dragwin, int offset); void set_fraction(win_T *wp); void win_new_height(win_T *wp, int height); void scroll_to_fraction(win_T *wp, int prev_height); void win_new_width(win_T *wp, int width); void win_comp_scroll(win_T *wp); void command_height(void); void last_status(int morewin); int tabline_height(void); int last_stl_height(int morewin); int min_rows(void); int only_one_window(void); void check_lnums(int do_curwin); void check_lnums_nested(int do_curwin); void reset_lnums(void); int make_snapshot(int idx); void restore_snapshot(int idx, int close_curwin); int win_hasvertsplit(void); int get_win_number(win_T *wp, win_T *first_win); int get_tab_number(tabpage_T *tp); char *check_colorcolumn(win_T *wp); int get_last_winid(void); /* vim: set ft=c : */