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| author | Michael Schröder <mls@suse.de> | 2022-01-04 03:08:05 +0200 |
|---|---|---|
| committer | Alexander Naumov <alexander_naumov@opensuse.org> | 2022-01-04 03:11:44 +0200 |
| commit | 282ec62662b3eeb79d919db9c1dc549f45787e1a (patch) | |
| tree | 8f2f3a4709922fe22937ceb5d0d264df3e7e7a0d | |
| parent | 99a906805a27b009289f5f0c2c12106214ff24fa (diff) | |
| download | screen-282ec62662b3eeb79d919db9c1dc549f45787e1a.tar.gz | |
bugfix CVE-2021-26937
It allows remote attackers to cause a denial of service
(invalid write access and application crash) or possibly
have unspecified other impact via a crafted UTF-8
character sequence.
bugfix: https://savannah.gnu.org/bugs/?60030
Signed-off-by: Alexander Naumov <alexander_naumov@opensuse.org>
| -rw-r--r-- | src/encoding.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/src/encoding.c b/src/encoding.c index e5db3e7..9cebddd 100644 --- a/src/encoding.c +++ b/src/encoding.c @@ -43,7 +43,7 @@ static int encmatch __P((char *, char *)); # ifdef UTF8 static int recode_char __P((int, int, int)); static int recode_char_to_encoding __P((int, int)); -static void comb_tofront __P((int, int)); +static void comb_tofront __P((int)); # ifdef DW_CHARS static int recode_char_dw __P((int, int *, int, int)); static int recode_char_dw_to_encoding __P((int, int *, int)); @@ -1263,6 +1263,8 @@ int c; {0x30000, 0x3FFFD}, }; + if (c >= 0xdf00 && c <= 0xdfff) + return 1; /* dw combining sequence */ return ((bisearch(c, wide, sizeof(wide) / sizeof(struct interval) - 1)) || (cjkwidth && bisearch(c, ambiguous, @@ -1330,11 +1332,12 @@ int c; } static void -comb_tofront(root, i) -int root, i; +comb_tofront(i) +int i; { for (;;) { + int root = i >= 0x700 ? 0x801 : 0x800; debug1("bring to front: %x\n", i); combchars[combchars[i]->prev]->next = combchars[i]->next; combchars[combchars[i]->next]->prev = combchars[i]->prev; @@ -1396,9 +1399,9 @@ struct mchar *mc; { /* full, recycle old entry */ if (c1 >= 0xd800 && c1 < 0xe000) - comb_tofront(root, c1 - 0xd800); + comb_tofront(c1 - 0xd800); i = combchars[root]->prev; - if (c1 == i + 0xd800) + if (i == 0x800 || i == 0x801 || c1 == i + 0xd800) { /* completely full, can't recycle */ debug("utf8_handle_comp: completely full!\n"); @@ -1422,7 +1425,7 @@ struct mchar *mc; mc->font = (i >> 8) + 0xd8; mc->fontx = 0; debug3("combinig char %x %x -> %x\n", c1, c, i + 0xd800); - comb_tofront(root, i); + comb_tofront(i); } #else /* !UTF8 */ |