vim/0001-patch-9.2.0846-security-heap-buffer-overflow-in-set_.patch
2026-09-10 07:23:28 -04:00

58 lines
2.3 KiB
Diff

From 6202f4f217c55590990e9562bf225be75e2367ce Mon Sep 17 00:00:00 2001
From: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Date: Fri, 24 Jul 2026 00:58:37 +0900
Subject: [PATCH] patch 9.2.0846: [security]: heap buffer overflow in
set_sofo()
Problem: [security]: heap buffer overflow in set_sofo()
(Yazan Balawneh)
Solution: Reset sl_sal_first (Yasuhiro Matsumoto).
A crafted spell file with an empty SN_SAL section before an SN_SOFO
section reaches set_sofo() with sl_sal_first[] already set to -1 by
set_sal_first(). The counting loop then under-counts colliding
multi-byte "from" characters, allocates an undersized list and writes
past its end.
Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-9jqx-hgpr-6v64
Signed-off-by: Yasuhiro Matsumoto <mattn.jp@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
---
src/spellfile.c | 4 +++-
src/testdir/test_spellfile.vim | 5 +++++
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/spellfile.c b/src/spellfile.c
index 988bb56c0..5e263d3e2 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -1431,7 +1431,9 @@ set_sofo(slang_T *lp, char_u *from, char_u *to)
gap->ga_len = 256;
// First count the number of items for each list. Temporarily use
- // sl_sal_first[] for this.
+ // sl_sal_first[] for this. Reset it first: a preceding SN_SAL section
+ // may have set the entries to -1 via set_sal_first().
+ vim_memset(lp->sl_sal_first, 0, sizeof(salfirst_T) * 256);
for (p = from, s = to; *p != NUL && *s != NUL; )
{
c = mb_cptr2char_adv(&p);
diff --git a/src/testdir/test_spellfile.vim b/src/testdir/test_spellfile.vim
index a5dde6d21..82f6ae465 100644
--- a/src/testdir/test_spellfile.vim
+++ b/src/testdir/test_spellfile.vim
@@ -322,6 +322,11 @@ func Test_spellfile_format_error()
" SN_SOFO: multi-byte characters in sofofrom and sofoto
call Spellfile_Test(0z0600000000080002CF810002CF82FF000000000000000000000000, '')
+ " SN_SAL (empty) followed by SN_SOFO with two multi-byte 'from' characters
+ " sharing the same low byte. A preceding SN_SAL poisons sl_sal_first[], so
+ " without a reset set_sofo() under-counts and writes out of bounds.
+ call Spellfile_Test(0z05000000000300000006000000000A0004CAABCEAB00024142FF000000000000000000000000, '')
+
" SN_COMPOUND: compmax is less than 2
call Spellfile_Test(0z08000000000101, 'E759:')