Mercurial > vim
changeset 33865:8cdb69ea3711 v9.0.2143
patch 9.0.2143: [security]: buffer-overflow in ex_substitute
Commit: https://github.com/vim/vim/commit/abfa13ebe92d81aaf66669c428d767847b577453
Author: Christian Brabandt <cb@256bit.org>
Date: Thu Nov 30 11:32:18 2023 +0100
patch 9.0.2143: [security]: buffer-overflow in ex_substitute
Problem: [security]: buffer-overflow in ex_substitute
Solution: clear memory after allocating
When allocating the new_start pointer in ex_substitute() the memory
pointer points to some garbage that the following for loop in
ex_cmds.c:4743 confuses and causes it to accessing the new_start pointer
beyond it's size, leading to a buffer-overlow.
So fix this by using alloc_clear() instead of alloc(), which will
clear the memory by NUL and therefore cause the loop to terminate
correctly.
Reported by @henices, thanks!
closes: #13596
Signed-off-by: Christian Brabandt <cb@256bit.org>
| author | Christian Brabandt <cb@256bit.org> |
|---|---|
| date | Sun, 10 Dec 2023 15:16:05 +0100 |
| parents | 6e4c686b6b5b |
| children | 06a2e6f91c2a |
| files | src/ex_cmds.c src/testdir/crash/poc_ex_substitute src/testdir/test_crash.vim src/version.c |
| diffstat | 4 files changed, 16 insertions(+), 3 deletions(-) [+] |
line wrap: on
line diff
--- a/src/ex_cmds.c +++ b/src/ex_cmds.c @@ -4650,7 +4650,7 @@ ex_substitute(exarg_T *eap) * too many calls to alloc()/free()). */ new_start_len = needed_len + 50; - if ((new_start = alloc(new_start_len)) == NULL) + if ((new_start = alloc_clear(new_start_len)) == NULL) goto outofmem; *new_start = NUL; new_end = new_start; @@ -4667,7 +4667,7 @@ ex_substitute(exarg_T *eap) if (needed_len > (int)new_start_len) { new_start_len = needed_len + 50; - if ((p1 = alloc(new_start_len)) == NULL) + if ((p1 = alloc_clear(new_start_len)) == NULL) { vim_free(new_start); goto outofmem;
new file mode 100644 index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..bcf1286512f21a787dcd048ac1eb7f3611db47e3 GIT binary patch literal 135 zc$_OvRY=WC&QHnAOSer)O)5=SuvAFp$|=!T;NmL&|DQpvm`h(%KSqJ8nE5}Ky=_rR zP>y|BrUI7%SBW1?NoFor{)89|;iAP{>OiUN)YO6kg?tUof@B4*vSKcS;^d<L83GI` Lsa#O1IG+mubIvNu
--- a/src/testdir/test_crash.vim +++ b/src/testdir/test_crash.vim @@ -117,7 +117,7 @@ func Test_crash1_2() " The following used to crash Vim let opts = #{cmd: 'sh'} let vim = GetVimProg() - let result = 'X_crash1_1_result.txt' + let result = 'X_crash1_2_result.txt' let buf = RunVimInTerminal('sh', opts) @@ -149,6 +149,17 @@ func Test_crash1_2() \ ' ; echo "crash 4: [OK]" >> '.. result .. "\<cr>") call TermWait(buf, 150) + let file = 'crash/poc_ex_substitute' + let cmn_args = "%s -u NONE -i NONE -n -e -s -S %s -c ':qa!'" + let args = printf(cmn_args, vim, file) + " just make sure it runs, we don't care about the resulting echo + call term_sendkeys(buf, args .. "\<cr>") + " There is no output generated in Github CI for the asan clang build. + " so just skip generating the ouput. + " call term_sendkeys(buf, args .. + " \ ' && echo "crash 5: [OK]" >> '.. result .. "\<cr>") + call TermWait(buf, 150) + " clean up exe buf .. "bw!"