vim: Security Fix for CVE-2026-55693

Picking patch as per [1], and same patch is mentioned in [2]

References:
[1] https://nvd.nist.gov/vuln/detail/CVE-2026-55693
[2] https://security-tracker.debian.org/tracker/CVE-2026-55693

(From OE-Core rev: f4d6729cf38708effd445aa739bfd34d3adda3d0)

Signed-off-by: Siddharth Doshi <sdoshi@mvista.com>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/vim/files/CVE-2026-55693.patch

@@ -0,0 +1,88 @@
+From 315b35adb406138c962bcc653db95acc3c87c8ab Mon Sep 17 00:00:00 2001
+From: Christian Brabandt <cb@256bit.org>
+Date: Mon, 15 Jun 2026 19:39:08 +0000
+Subject: [PATCH 09/17] patch 9.2.0653: [security]: out-of-bounds write in
+ tree_count_words()
+
+Problem:  [security]: a crafted spell file can drive tree_count_words()
+          past the end of its MAXWLEN-sized depth arrays; the descent
+          loop has no depth bound.
+Solution: only descend while depth < MAXWLEN - 1, as the sibling trie
+          walkers already do; apply the same guard to sug_filltree().
+
+Github Security Advisory:
+https://github.com/vim/vim/security/advisories/GHSA-wgh4-64f7-q3jq
+
+Supported by AI.
+
+Signed-off-by: Christian Brabandt <cb@256bit.org>
+
+Upstream-Status: Backport [https://github.com/vim/vim/commit/a80874d9b84a01040e3d1aef2d4a59e1934dafb7]
+CVE: CVE-2026-55693
+Signed-off-by: Siddharth Doshi <sdoshi@mvista.com>
+---
+ src/spellfile.c                |  4 ++--
+ src/testdir/test_spellfile.vim | 27 +++++++++++++++++++++++++++
+ 2 files changed, 29 insertions(+), 2 deletions(-)
+
+diff --git a/src/spellfile.c b/src/spellfile.c
+index 0b9536dc16..0010d9aa27 100644
+--- a/src/spellfile.c
++++ b/src/spellfile.c
+@@ -645,7 +645,7 @@ tree_count_words(char_u *byts, idx_T *idxs)
+ 		    ++curi[depth];
+ 		}
+ 	    }
+-	    else
++	    else if (depth < MAXWLEN - 1)
+ 	    {
+ 		// Normal char, go one level deeper to count the words.
+ 		++depth;
+@@ -5648,7 +5648,7 @@ sug_filltree(spellinfo_T *spin, slang_T *slang)
+ 		    ++curi[depth];
+ 		}
+ 	    }
+-	    else
++	    else if (depth < MAXWLEN - 1)
+ 	    {
+ 		// Normal char, go one level deeper.
+ 		tword[depth++] = c;
+diff --git a/src/testdir/test_spellfile.vim b/src/testdir/test_spellfile.vim
+index b72974ed07..e5f8c5778f 100644
+--- a/src/testdir/test_spellfile.vim
++++ b/src/testdir/test_spellfile.vim
+@@ -1166,4 +1166,31 @@ func Test_mkspell_empty_dic()
+ endfunc
+ 
+ 
++func Test_spell_sug_tree_count_words_overflow()
++  " A crafted .spl/.sug pair with a BY_INDEX self-cycle in the fold word tree
++  " parses cleanly (shared refs aren't recursed, so read_tree_node()'s depth
++  " cap never trips), but drove tree_count_words() past its MAXWLEN-sized depth
++  " arrays -> stack out-of-bounds write.  The walk only happens when
++  " spellsuggest() loads the matching .sug.  Reaching the assert == no OOB.
++  call mkdir('Xrtp/spell', 'pR')
++  " VIMspell + v50, SN_SUGFILE(ts), SN_END, LWORDTREE{node:1,BY_INDEX->0,'A'},
++  " empty KWORDTREE/PREFIXTREE
++  let spl = eval('0z56494D7370656C6C320B0000000008000000001234'
++        \ .. '5678FF000000020101000000410000000000000000')
++  " VIMsug + v1, matching ts, SUGWORDTREE word "a", empty SUGTABLE
++  let sug = 0z56494D737567010000000012345678000000040161010000000000
++  call writefile(spl, 'Xrtp/spell/xx.utf-8.spl', 'b')
++  call writefile(sug, 'Xrtp/spell/xx.utf-8.sug', 'b')
++
++  new
++  set runtimepath+=./Xrtp
++  set spelllang=xx
++  set spell
++  " Unpatched: OOB write here (ASan abort, or crash).  Patched: returns a list.
++  call assert_equal(v:t_list, type(spellsuggest('helloo')))
++
++  set spell& spelllang& runtimepath&
++  bwipe!
++endfunc
++
+ " vim: shiftwidth=2 sts=2 expandtab
+-- 
+2.44.4
+

meta/recipes-support/vim/vim.inc

@@ -41,6 +41,7 @@ SRC_URI = "git://github.com/vim/vim.git;branch=master;protocol=https \
            file://CVE-2026-43961.patch \
            file://CVE-2026-47162.patch \
            file://CVE-2026-47167.patch \
+           file://CVE-2026-55693.patch \
            "
 
 PV .= ".1683"