commit 5f871007d7a8b78354e14771fd1a3900e41a5edd
parent 565cfa04eb00125eae2ade200591d435f5a86ad0
Author: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Date: Tue, 6 Jan 2026 12:16:34 +0000
vim-patch:9.1.2058: b_locked_split is not checked for :sbuffer
Problem: b_locked_split is not checked for :sbuffer, which allows
autocommands to leave windows open to freed buffers.
Solution: In do_buffer_ext, check just before possibly splitting, after
handling 'switchbuf'. Leave win_split to handle the check for
curbuf. (needed even if curbuf is not the target, as setting
the buffer after splitting may fail) (Sean Dewar)
closes: vim/vim#19096
https://github.com/vim/vim/commit/ac5c8ab6cc655f42f61f690058be8483fae71d4a
Co-authored-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Diffstat:
2 files changed, 77 insertions(+), 27 deletions(-)
diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
@@ -1323,17 +1323,10 @@ static int do_buffer_ext(int action, int start, int dir, int count, int flags)
return FAIL;
}
- if (action == DOBUF_GOTO && buf != curbuf) {
- if (!check_can_set_curbuf_forceit((flags & DOBUF_FORCEIT) != 0)) {
- // disallow navigating to another buffer when 'winfixbuf' is applied
- return FAIL;
- }
- if (buf->b_locked_split) {
- // disallow navigating to a closing buffer, which like splitting,
- // can result in more windows displaying it
- emsg(_(e_cannot_switch_to_a_closing_buffer));
- return FAIL;
- }
+ if (action == DOBUF_GOTO && buf != curbuf
+ && !check_can_set_curbuf_forceit((flags & DOBUF_FORCEIT) != 0)) {
+ // disallow navigating to another buffer when 'winfixbuf' is applied
+ return FAIL;
}
if ((action == DOBUF_GOTO || action == DOBUF_SPLIT) && (buf->b_flags & BF_DUMMY)) {
@@ -1558,15 +1551,17 @@ static int do_buffer_ext(int action, int start, int dir, int count, int flags)
}
// make "buf" the current buffer
- if (action == DOBUF_SPLIT) { // split window first
- // If 'switchbuf' is set jump to the window containing "buf".
- if (swbuf_goto_win_with_buf(buf) != NULL) {
- return OK;
- }
-
- if (win_split(0, 0) == FAIL) {
- return FAIL;
- }
+ // If 'switchbuf' is set jump to the window containing "buf".
+ if (action == DOBUF_SPLIT && swbuf_goto_win_with_buf(buf) != NULL) {
+ return OK;
+ }
+ // Whether splitting or not, don't open a closing buffer in more windows.
+ if (buf != curbuf && buf->b_locked_split) {
+ emsg(_(e_cannot_switch_to_a_closing_buffer));
+ return FAIL;
+ }
+ if (action == DOBUF_SPLIT && win_split(0, 0) == FAIL) { // split window first
+ return FAIL;
}
// go to current buffer - nothing to do
diff --git a/test/old/testdir/test_buffer.vim b/test/old/testdir/test_buffer.vim
@@ -591,34 +591,89 @@ endfunc
func Test_closed_buffer_still_in_window()
%bw!
+ let s:fired = 0
let s:w = win_getid()
new
let s:b = bufnr()
setl bufhidden=wipe
-
augroup ViewClosedBuffer
autocmd!
- autocmd BufUnload * ++once call assert_fails(
- \ 'call win_execute(s:w, "' .. s:b .. 'b")', 'E1546:')
+ autocmd BufUnload * ++once let s:fired += 1 | call assert_fails(
+ \ 'call win_execute(s:w, "' .. s:b .. 'buffer")', 'E1546:')
augroup END
quit!
" Previously resulted in s:b being curbuf while unloaded (no memfile).
+ call assert_equal(1, s:fired)
call assert_equal(1, bufloaded(bufnr()))
call assert_equal(0, bufexists(s:b))
+ %bw!
+
+ new flobby
+ let s:w = win_getid()
+ let s:b = bufnr()
+ setl bufhidden=wipe
+ augroup ViewClosedBuffer
+ autocmd!
+ autocmd BufUnload * ++once let s:fired += 1
+ \| wincmd p
+ \| call assert_notequal(s:w, win_getid())
+ \| call assert_notequal(s:b, bufnr())
+ \| execute s:b 'sbuffer'
+ \| call assert_equal(s:w, win_getid())
+ \| call assert_equal(s:b, bufnr())
+ augroup END
+ " Not a problem if 'switchbuf' switches to an existing window instead.
+ set switchbuf=useopen
+ quit!
+ call assert_equal(2, s:fired)
+ call assert_equal(0, bufexists(s:b))
+ set switchbuf&
+ %bw!
+
+ edit floob
+ let s:b = bufnr()
+ enew
+ augroup ViewClosedBuffer
+ autocmd!
+ autocmd BufWipeout * ++once let s:fired += 1
+ \| call assert_fails(s:b .. 'sbuffer | wincmd p', 'E1546:')
+ \| call assert_equal(1, winnr('$')) " :sbuffer shouldn't have split.
+ augroup END
+ " Used to be a heap UAF.
+ execute s:b 'bwipeout!'
+ call assert_equal(3, s:fired)
+ call assert_equal(0, bufexists(s:b))
+ %bw!
+
+ edit flarb
+ let s:b = bufnr()
+ enew
+ let b2 = bufnr()
+ augroup ViewClosedBuffer
+ autocmd!
+ autocmd BufWipeout * ++once let s:fired += 1
+ \| call assert_fails(s:b .. 'sbuffer', 'E1159:')
+ augroup END
+ " :sbuffer still should fail if curbuf is closing, even if it's not the target
+ " buffer (as switching buffers can fail after the split)
+ bwipeout!
+ call assert_equal(4, s:fired)
+ call assert_equal(0, bufexists(b2))
+ %bw!
let s:w = win_getid()
split
new
let s:b = bufnr()
-
augroup ViewClosedBuffer
autocmd!
- autocmd BufWipeout * ++once call win_gotoid(s:w)
- \| call assert_fails(s:b .. 'b', 'E1546:') | wincmd p
+ autocmd BufWipeout * ++once let s:fired += 1 | call win_gotoid(s:w)
+ \| call assert_fails(s:b .. 'buffer', 'E1546:') | wincmd p
augroup END
bw! " Close only this buffer first; used to be a heap UAF.
+ call assert_equal(5, s:fired)
- unlet! s:w s:b
+ unlet! s:w s:b s:fired
autocmd! ViewClosedBuffer
%bw!
endfunc
