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-rw-r--r--debian/changelog8
-rw-r--r--debian/gbp.conf2
-rw-r--r--debian/patches/series5
-rw-r--r--debian/patches/upstream/wall-convert-homebrew-buffering-to-open_memstream.patch165
-rw-r--r--debian/patches/upstream/wall-fix-calloc-cal-Werror-calloc-transposed-args.patch27
-rw-r--r--debian/patches/upstream/wall-fix-escape-sequence-Injection-CVE-2024-28085.patch25
-rw-r--r--debian/patches/upstream/wall-use-fputs_careful.patch214
-rw-r--r--debian/patches/upstream/write-correctly-handle-wide-characters.patch196
-rwxr-xr-xdebian/rules3
9 files changed, 644 insertions, 1 deletions
diff --git a/debian/changelog b/debian/changelog
index 42e0eb4..b421cd2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+util-linux (2.36.1-8+deb11u2) bullseye-security; urgency=high
+
+ * d/gbp.conf: update for stable release
+ * Add upstream patches to fix CVE-2024-28085 (Closes: #1067849)
+ * No longer install wall, write setgid tty to address CVE-2024-28085
+
+ -- Chris Hofstaedtler <zeha@debian.org> Thu, 28 Mar 2024 11:09:40 +0100
+
util-linux (2.36.1-8+deb11u1) bullseye-security; urgency=high
* Non-maintainer upload by the Security Team.
diff --git a/debian/gbp.conf b/debian/gbp.conf
index 1756df7..3f6658c 100644
--- a/debian/gbp.conf
+++ b/debian/gbp.conf
@@ -1,5 +1,5 @@
[DEFAULT]
-debian-branch = master
+debian-branch = debian/bullseye
upstream-branch = upstream
pristine-tar = True
compression = xz
diff --git a/debian/patches/series b/debian/patches/series
index 467522b..dded791 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -10,3 +10,8 @@ upstream/CVE-2021-37600-sys-utils-ipcutils-be-careful-when-call-calloc.patch
debian/backport-ul_strtou64-function.patch
upstream/libmount-fix-UID-check-for-FUSE-umount-CVE-2021-3995.patch
upstream/libmount-fix-deleted-suffix-issue-CVE-2021-3996.patch
+upstream/write-correctly-handle-wide-characters.patch
+upstream/wall-convert-homebrew-buffering-to-open_memstream.patch
+upstream/wall-use-fputs_careful.patch
+upstream/wall-fix-calloc-cal-Werror-calloc-transposed-args.patch
+upstream/wall-fix-escape-sequence-Injection-CVE-2024-28085.patch
diff --git a/debian/patches/upstream/wall-convert-homebrew-buffering-to-open_memstream.patch b/debian/patches/upstream/wall-convert-homebrew-buffering-to-open_memstream.patch
new file mode 100644
index 0000000..7542b1c
--- /dev/null
+++ b/debian/patches/upstream/wall-convert-homebrew-buffering-to-open_memstream.patch
@@ -0,0 +1,165 @@
+From: =?utf-8?b?0L3QsNCx?= <nabijaczleweli@nabijaczleweli.xyz>
+Date: Wed, 15 Mar 2023 16:16:43 +0100
+Subject: wall: convert homebrew buffering to open_memstream()
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 8bit
+
+The struct buffer system duplicates a plethora of standard I/O
+functions (including a fork of fputc_careful())
+and adds a lot of complexity ‒ open_memstream() is standard,
+and fits perfectly into this niche
+---
+ term-utils/wall.c | 94 ++++++++++++-------------------------------------------
+ 1 file changed, 20 insertions(+), 74 deletions(-)
+
+diff --git a/term-utils/wall.c b/term-utils/wall.c
+index 97d9a56..97623b8 100644
+--- a/term-utils/wall.c
++++ b/term-utils/wall.c
+@@ -273,73 +273,22 @@ int main(int argc, char **argv)
+ exit(EXIT_SUCCESS);
+ }
+
+-struct buffer {
+- size_t sz;
+- size_t used;
+- char *data;
+-};
+-
+-static void buf_enlarge(struct buffer *bs, size_t len)
++static void buf_putc_careful(FILE *fs, int c)
+ {
+- if (bs->sz == 0 || len > bs->sz - bs->used) {
+- bs->sz += len < 128 ? 128 : len;
+- bs->data = xrealloc(bs->data, bs->sz);
+- }
+-}
+-
+-static void buf_puts(struct buffer *bs, const char *s)
+-{
+- size_t len = strlen(s);
+-
+- buf_enlarge(bs, len + 1);
+- memcpy(bs->data + bs->used, s, len + 1);
+- bs->used += len;
+-}
+-
+-static void buf_printf(struct buffer *bs, const char *fmt, ...)
+-{
+- int rc;
+- va_list ap;
+- size_t limit;
+-
+- buf_enlarge(bs, 0); /* default size */
+- limit = bs->sz - bs->used;
+-
+- va_start(ap, fmt);
+- rc = vsnprintf(bs->data + bs->used, limit, fmt, ap);
+- va_end(ap);
+-
+- if (rc >= 0 && (size_t) rc >= limit) { /* not enough, enlarge */
+- buf_enlarge(bs, (size_t)rc + 1);
+- limit = bs->sz - bs->used;
+- va_start(ap, fmt);
+- rc = vsnprintf(bs->data + bs->used, limit, fmt, ap);
+- va_end(ap);
+- }
+-
+- if (rc > 0)
+- bs->used += rc;
+-}
+-
+-static void buf_putc_careful(struct buffer *bs, int c)
+-{
+- if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n') {
+- buf_enlarge(bs, 1);
+- bs->data[bs->used++] = c;
+- } else if (!c_isascii(c))
+- buf_printf(bs, "\\%3o", (unsigned char)c);
+- else {
+- char tmp[] = { '^', c ^ 0x40, '\0' };
+- buf_puts(bs, tmp);
+- }
++ if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n')
++ fputc(c, fs);
++ else if (!c_isascii(c))
++ fprintf(fs, "\\%3o", (unsigned char)c);
++ else
++ fputs((char[]){ '^', c ^ 0x40, '\0' }, fs);
+ }
+
+ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ size_t *mbufsize, int print_banner)
+ {
+- struct buffer _bs = {.used = 0}, *bs = &_bs;
+ register int ch, cnt;
+- char *p, *lbuf;
++ char *p, *lbuf, *retbuf;
++ FILE * fs = open_memstream(&retbuf, mbufsize);
+ long line_max;
+
+ line_max = sysconf(_SC_LINE_MAX);
+@@ -379,15 +328,15 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ */
+ /* snprintf is not always available, but the sprintf's here
+ will not overflow as long as %d takes at most 100 chars */
+- buf_printf(bs, "\r%*s\r\n", TERM_WIDTH, " ");
++ fprintf(fs, "\r%*s\r\n", TERM_WIDTH, " ");
+
+ snprintf(lbuf, line_max,
+ _("Broadcast message from %s@%s (%s) (%s):"),
+ whom, hostname, where, date);
+- buf_printf(bs, "%-*.*s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf);
++ fprintf(fs, "%-*.*s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf);
+ free(hostname);
+ }
+- buf_printf(bs, "%*s\r\n", TERM_WIDTH, " ");
++ fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");
+
+ if (mvec) {
+ /*
+@@ -396,11 +345,11 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ int i;
+
+ for (i = 0; i < mvecsz; i++) {
+- buf_puts(bs, mvec[i]);
++ fputs(mvec[i], fs);
+ if (i < mvecsz - 1)
+- buf_puts(bs, " ");
++ fputc(' ', fs);
+ }
+- buf_puts(bs, "\r\n");
++ fputs("\r\n", fs);
+ } else {
+ /*
+ * read message from <file>
+@@ -428,23 +377,20 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ while (fgets(lbuf, line_max, stdin)) {
+ for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
+ if (cnt == TERM_WIDTH || ch == '\n') {
+- for (; cnt < TERM_WIDTH; ++cnt)
+- buf_puts(bs, " ");
+- buf_puts(bs, "\r\n");
++ fprintf(fs, "%*s\r\n", TERM_WIDTH - cnt, "");
+ cnt = 0;
+ }
+ if (ch == '\t')
+ cnt += (7 - (cnt % 8));
+ if (ch != '\n')
+- buf_putc_careful(bs, ch);
++ buf_putc_careful(fs, ch);
+ }
+ }
+ }
+- buf_printf(bs, "%*s\r\n", TERM_WIDTH, " ");
++ fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");
+
+ free(lbuf);
+
+- bs->data[bs->used] = '\0'; /* be paranoid */
+- *mbufsize = bs->used;
+- return bs->data;
++ fclose(fs);
++ return retbuf;
+ }
diff --git a/debian/patches/upstream/wall-fix-calloc-cal-Werror-calloc-transposed-args.patch b/debian/patches/upstream/wall-fix-calloc-cal-Werror-calloc-transposed-args.patch
new file mode 100644
index 0000000..8d123f0
--- /dev/null
+++ b/debian/patches/upstream/wall-fix-calloc-cal-Werror-calloc-transposed-args.patch
@@ -0,0 +1,27 @@
+From: Karel Zak <kzak@redhat.com>
+Date: Wed, 17 Jan 2024 12:37:08 +0100
+Subject: wall: fix calloc cal [-Werror=calloc-transposed-args]
+
+term-utils/wall.c:143:37: error: xcalloc sizes specified with sizeof in the earlier argument and not in the later argument [-Werror=calloc-transposed-args]
+ 143 | buf->groups = xcalloc(sizeof(*buf->groups), buf->ngroups);
+ | ^
+term-utils/wall.c:143:37: note: earlier argument should specify number of elements, later size of each element
+
+Signed-off-by: Karel Zak <kzak@redhat.com>
+---
+ term-utils/wall.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/term-utils/wall.c b/term-utils/wall.c
+index fa5e027..16dfb1f 100644
+--- a/term-utils/wall.c
++++ b/term-utils/wall.c
+@@ -134,7 +134,7 @@ static struct group_workspace *init_group_workspace(const char *group)
+
+ buf->requested_group = get_group_gid(group);
+ buf->ngroups = sysconf(_SC_NGROUPS_MAX) + 1; /* room for the primary gid */
+- buf->groups = xcalloc(sizeof(*buf->groups), buf->ngroups);
++ buf->groups = xcalloc(buf->ngroups, sizeof(*buf->groups));
+
+ return buf;
+ }
diff --git a/debian/patches/upstream/wall-fix-escape-sequence-Injection-CVE-2024-28085.patch b/debian/patches/upstream/wall-fix-escape-sequence-Injection-CVE-2024-28085.patch
new file mode 100644
index 0000000..c1160fe
--- /dev/null
+++ b/debian/patches/upstream/wall-fix-escape-sequence-Injection-CVE-2024-28085.patch
@@ -0,0 +1,25 @@
+From: Karel Zak <kzak@redhat.com>
+Date: Thu, 21 Mar 2024 11:16:20 +0100
+Subject: wall: fix escape sequence Injection [CVE-2024-28085]
+
+Let's use for all cases the same output function.
+
+Reported-by: Skyler Ferrante <sjf5462@rit.edu>
+Signed-off-by: Karel Zak <kzak@redhat.com>
+---
+ term-utils/wall.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/term-utils/wall.c b/term-utils/wall.c
+index 16dfb1f..a497d91 100644
+--- a/term-utils/wall.c
++++ b/term-utils/wall.c
+@@ -329,7 +329,7 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ int i;
+
+ for (i = 0; i < mvecsz; i++) {
+- fputs(mvec[i], fs);
++ fputs_careful(mvec[i], fs, '^', true, TERM_WIDTH);
+ if (i < mvecsz - 1)
+ fputc(' ', fs);
+ }
diff --git a/debian/patches/upstream/wall-use-fputs_careful.patch b/debian/patches/upstream/wall-use-fputs_careful.patch
new file mode 100644
index 0000000..a817c60
--- /dev/null
+++ b/debian/patches/upstream/wall-use-fputs_careful.patch
@@ -0,0 +1,214 @@
+From: =?utf-8?b?0L3QsNCx?= <nabijaczleweli@nabijaczleweli.xyz>
+Date: Wed, 15 Mar 2023 16:16:48 +0100
+Subject: wall: use fputs_careful()
+
+LINE_MAX only applies to teletypes in canonical mode: when stdin is a
+file, it could still very much tear; start off at 512 for the sprintf(),
+then use getline() like in write.
+
+The line wrapping has one suboptimal edge-case:
+ $ wall < all
+
+ Broadcast message from nabijaczleweli@tarta (pts/4) (Tue Mar 14 22:31:25
+ 2023):
+
+ ^N^O^P^Q^R^S^T^U^V^W^X^Y^Z^[^\^]^^^_
+ !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJ
+ KLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~^?\200\201\202\203\204\205\206
+ \207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232
+ \233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256
+ \257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302
+ \303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326
+ \327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352
+ \353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376
+ \377
+but that's a pathological input, and the result is still infinitely
+better than it was before, so fixing that is more trouble than it's
+worth.
+
+Bug-Debian: https://bugs.debian.org/826596
+---
+ include/carefulputc.h | 42 +++++++++++++++++++++++++++++++++---------
+ login-utils/last.c | 2 +-
+ term-utils/wall.c | 38 ++++++--------------------------------
+ term-utils/write.c | 2 +-
+ 4 files changed, 41 insertions(+), 43 deletions(-)
+
+diff --git a/include/carefulputc.h b/include/carefulputc.h
+index 4f74526..51d1c99 100644
+--- a/include/carefulputc.h
++++ b/include/carefulputc.h
+@@ -6,6 +6,7 @@
+ #include <ctype.h>
+ #ifdef HAVE_WIDECHAR
+ #include <wctype.h>
++#include <wchar.h>
+ #endif
+ #include <stdbool.h>
+
+@@ -15,18 +16,35 @@
+ * A puts() for use in write and wall (that sometimes are sgid tty).
+ * It avoids control and invalid characters.
+ * The locale of the recipient is nominally unknown,
+- * but it's a solid bet that the encoding is compatible with the author's.
++ * but it's a solid bet that it's compatible with the author's.
++ * Use soft_width=0 to disable wrapping.
+ */
+-static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf)
++static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf, int soft_width)
+ {
+- int ret = 0;
++ int ret = 0, col = 0;
+
+ for (size_t slen = strlen(s); *s; ++s, --slen) {
+- if (*s == '\n')
++ if (*s == '\t')
++ col += (7 - (col % 8)) - 1;
++ else if (*s == '\r')
++ col = -1;
++ else if (*s == '\a')
++ --col;
++
++ if ((soft_width && col >= soft_width) || *s == '\n') {
++ if (soft_width) {
++ fprintf(fp, "%*s", soft_width - col, "");
++ col = 0;
++ }
+ ret = fputs(cr_lf ? "\r\n" : "\n", fp);
+- else if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r')
++ if (*s == '\n' || ret < 0)
++ goto wrote;
++ }
++
++ if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r') {
+ ret = putc(*s, fp);
+- else if (!c_isascii(*s)) {
++ ++col;
++ } else if (!c_isascii(*s)) {
+ #ifdef HAVE_WIDECHAR
+ wchar_t w;
+ size_t clen = mbtowc(&w, s, slen);
+@@ -35,21 +53,27 @@ static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool
+ case (size_t)-1: // EILSEQ
+ mbtowc(NULL, NULL, 0);
+ nonprint:
+- ret = fprintf(fp, "\\%3hho", *s);
++ col += ret = fprintf(fp, "\\%3hho", *s);
+ break;
+ default:
+ if(!iswprint(w))
+ goto nonprint;
+ ret = fwrite(s, 1, clen, fp);
++ if (soft_width)
++ col += wcwidth(w);
+ s += clen - 1;
+ slen -= clen - 1;
+ break;
+ }
+ #else
+- ret = fprintf(fp, "\\%3hho", *s);
++ col += ret = fprintf(fp, "\\%3hho", *s);
+ #endif
+- } else
++ } else {
+ ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
++ col += 2;
++ }
++
++ wrote:
+ if (ret < 0)
+ return EOF;
+ }
+diff --git a/login-utils/last.c b/login-utils/last.c
+index c5984f1..8386f08 100644
+--- a/login-utils/last.c
++++ b/login-utils/last.c
+@@ -550,7 +550,7 @@ static int list(const struct last_control *ctl, struct utmpx *p, time_t logout_t
+ /*
+ * Print out "final" string safely.
+ */
+- fputs_careful(final, stdout, '*', false);
++ fputs_careful(final, stdout, '*', false, 0);
+
+ if (len < 0 || (size_t)len >= sizeof(final))
+ putchar('\n');
+diff --git a/term-utils/wall.c b/term-utils/wall.c
+index 97623b8..fa5e027 100644
+--- a/term-utils/wall.c
++++ b/term-utils/wall.c
+@@ -273,29 +273,13 @@ int main(int argc, char **argv)
+ exit(EXIT_SUCCESS);
+ }
+
+-static void buf_putc_careful(FILE *fs, int c)
+-{
+- if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n')
+- fputc(c, fs);
+- else if (!c_isascii(c))
+- fprintf(fs, "\\%3o", (unsigned char)c);
+- else
+- fputs((char[]){ '^', c ^ 0x40, '\0' }, fs);
+-}
+-
+ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ size_t *mbufsize, int print_banner)
+ {
+- register int ch, cnt;
+- char *p, *lbuf, *retbuf;
++ char *lbuf, *retbuf;
+ FILE * fs = open_memstream(&retbuf, mbufsize);
+- long line_max;
+-
+- line_max = sysconf(_SC_LINE_MAX);
+- if (line_max <= 0)
+- line_max = 512;
+-
+- lbuf = xmalloc(line_max);
++ size_t lbuflen = 512;
++ lbuf = xmalloc(lbuflen);
+
+ if (print_banner == TRUE) {
+ char *hostname = xgethostname();
+@@ -330,7 +314,7 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ will not overflow as long as %d takes at most 100 chars */
+ fprintf(fs, "\r%*s\r\n", TERM_WIDTH, " ");
+
+- snprintf(lbuf, line_max,
++ snprintf(lbuf, lbuflen,
+ _("Broadcast message from %s@%s (%s) (%s):"),
+ whom, hostname, where, date);
+ fprintf(fs, "%-*.*s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf);
+@@ -374,18 +358,8 @@ static char *makemsg(char *fname, char **mvec, int mvecsz,
+ /*
+ * Read message from stdin.
+ */
+- while (fgets(lbuf, line_max, stdin)) {
+- for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
+- if (cnt == TERM_WIDTH || ch == '\n') {
+- fprintf(fs, "%*s\r\n", TERM_WIDTH - cnt, "");
+- cnt = 0;
+- }
+- if (ch == '\t')
+- cnt += (7 - (cnt % 8));
+- if (ch != '\n')
+- buf_putc_careful(fs, ch);
+- }
+- }
++ while (getline(&lbuf, &lbuflen, stdin) >= 0)
++ fputs_careful(lbuf, fs, '^', true, TERM_WIDTH);
+ }
+ fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");
+
+diff --git a/term-utils/write.c b/term-utils/write.c
+index 710a58c..1d57fce 100644
+--- a/term-utils/write.c
++++ b/term-utils/write.c
+@@ -276,7 +276,7 @@ static void do_write(const struct write_control *ctl)
+ if (signal_received)
+ break;
+
+- if (fputs_careful(line, stdout, '^', true) == EOF)
++ if (fputs_careful(line, stdout, '^', true, 0) == EOF)
+ err(EXIT_FAILURE, _("carefulputc failed"));
+ }
+ free(line);
diff --git a/debian/patches/upstream/write-correctly-handle-wide-characters.patch b/debian/patches/upstream/write-correctly-handle-wide-characters.patch
new file mode 100644
index 0000000..f931749
--- /dev/null
+++ b/debian/patches/upstream/write-correctly-handle-wide-characters.patch
@@ -0,0 +1,196 @@
+From: =?utf-8?b?0L3QsNCx?= <nabijaczleweli@nabijaczleweli.xyz>
+Date: Wed, 15 Mar 2023 16:16:31 +0100
+Subject: write: correctly handle wide characters
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 8bit
+
+Do this by replacing fputc_careful() (notice that the description said
+it's locale-aware ‒ it very much is /not/), with a fputs_careful() which
+does the same thing, but if it were to output a byte in the \123 format,
+first it checks whether this byte starts a valid multibyte character.
+
+If it does, and that character is printable, write it verbatim.
+This means that
+ echo 'foo åäö ąęćźżń bar' | write nabijaczleweli pts/4
+instead of
+ foo \303\245\303\244\303\266
+ \304\205\304\231\304\207\305\272\305\274\305\204 bar
+yields
+ foo åäö ąęćźżń bar
+or, more realistically, from a message I got earlier today,
+ Filip powiedzia\305\202 \305\274e zap\305\202aci jutro
+becomes
+ Filip powiedział że zapłaci jutro
+
+Invalid/non-printable sequences get processed as before.
+
+Line reading in write must become getline() to avoid dealing with
+partial characters: for example on input consisting solely of
+ąęćźżń, where every {1} is an instance, the output would be
+ {42}ąęć\305\272żń{84}ąęćź\305\274ń{84}ąęćźż\305\204{39}
+with just fixed-512 fgets()
+
+Bug-Debian: https://bugs.debian.org/826596
+---
+ include/carefulputc.h | 62 +++++++++++++++++++++++++++++++++++++--------------
+ login-utils/last.c | 4 +---
+ term-utils/write.c | 25 ++++++---------------
+ 3 files changed, 53 insertions(+), 38 deletions(-)
+
+diff --git a/include/carefulputc.h b/include/carefulputc.h
+index f1c0356..4f74526 100644
+--- a/include/carefulputc.h
++++ b/include/carefulputc.h
+@@ -1,31 +1,59 @@
+ #ifndef UTIL_LINUX_CAREFULPUTC_H
+ #define UTIL_LINUX_CAREFULPUTC_H
+
+-/*
+- * A putc() for use in write and wall (that sometimes are sgid tty).
+- * It avoids control characters in our locale, and also ASCII control
+- * characters. Note that the locale of the recipient is unknown.
+-*/
+ #include <stdio.h>
+ #include <string.h>
+ #include <ctype.h>
++#ifdef HAVE_WIDECHAR
++#include <wctype.h>
++#endif
++#include <stdbool.h>
+
+ #include "cctype.h"
+
+-static inline int fputc_careful(int c, FILE *fp, const char fail)
++/*
++ * A puts() for use in write and wall (that sometimes are sgid tty).
++ * It avoids control and invalid characters.
++ * The locale of the recipient is nominally unknown,
++ * but it's a solid bet that the encoding is compatible with the author's.
++ */
++static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf)
+ {
+- int ret;
+-
+- if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n')
+- ret = putc(c, fp);
+- else if (!c_isascii(c))
+- ret = fprintf(fp, "\\%3o", (unsigned char)c);
+- else {
+- ret = putc(fail, fp);
+- if (ret != EOF)
+- ret = putc(c ^ 0x40, fp);
++ int ret = 0;
++
++ for (size_t slen = strlen(s); *s; ++s, --slen) {
++ if (*s == '\n')
++ ret = fputs(cr_lf ? "\r\n" : "\n", fp);
++ else if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r')
++ ret = putc(*s, fp);
++ else if (!c_isascii(*s)) {
++#ifdef HAVE_WIDECHAR
++ wchar_t w;
++ size_t clen = mbtowc(&w, s, slen);
++ switch(clen) {
++ case (size_t)-2: // incomplete
++ case (size_t)-1: // EILSEQ
++ mbtowc(NULL, NULL, 0);
++ nonprint:
++ ret = fprintf(fp, "\\%3hho", *s);
++ break;
++ default:
++ if(!iswprint(w))
++ goto nonprint;
++ ret = fwrite(s, 1, clen, fp);
++ s += clen - 1;
++ slen -= clen - 1;
++ break;
++ }
++#else
++ ret = fprintf(fp, "\\%3hho", *s);
++#endif
++ } else
++ ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
++ if (ret < 0)
++ return EOF;
+ }
+- return (ret < 0) ? EOF : 0;
++ return 0;
+ }
+
+ /*
+diff --git a/login-utils/last.c b/login-utils/last.c
+index 9d71ba4..c5984f1 100644
+--- a/login-utils/last.c
++++ b/login-utils/last.c
+@@ -395,7 +395,6 @@ static int list(const struct last_control *ctl, struct utmpx *p, time_t logout_t
+ char final[512];
+ char utline[sizeof(p->ut_line) + 1];
+ char domain[256];
+- char *s;
+ int mins, hours, days;
+ int r, len;
+ struct last_timefmt *fmt;
+@@ -551,8 +550,7 @@ static int list(const struct last_control *ctl, struct utmpx *p, time_t logout_t
+ /*
+ * Print out "final" string safely.
+ */
+- for (s = final; *s; s++)
+- fputc_careful(*s, stdout, '*');
++ fputs_careful(final, stdout, '*', false);
+
+ if (len < 0 || (size_t)len >= sizeof(final))
+ putchar('\n');
+diff --git a/term-utils/write.c b/term-utils/write.c
+index 50f18dc..710a58c 100644
+--- a/term-utils/write.c
++++ b/term-utils/write.c
+@@ -223,21 +223,6 @@ static void signal_handler(int signo)
+ signal_received = signo;
+ }
+
+-/*
+- * write_line - like fputs(), but makes control characters visible and
+- * turns \n into \r\n.
+- */
+-static void write_line(char *s)
+-{
+- while (*s) {
+- const int c = *s++;
+-
+- if ((c == '\n' && fputc_careful('\r', stdout, '^') == EOF)
+- || fputc_careful(c, stdout, '^') == EOF)
+- err(EXIT_FAILURE, _("carefulputc failed"));
+- }
+-}
+-
+ /*
+ * do_write - actually make the connection
+ */
+@@ -247,7 +232,8 @@ static void do_write(const struct write_control *ctl)
+ struct passwd *pwd;
+ time_t now;
+ struct tm *tm;
+- char *host, line[512];
++ char *host, *line = NULL;
++ size_t linelen = 0;
+ struct sigaction sigact;
+
+ /* Determine our login name(s) before the we reopen() stdout */
+@@ -286,11 +272,14 @@ static void do_write(const struct write_control *ctl)
+ free(host);
+ printf("\r\n");
+
+- while (fgets(line, sizeof(line), stdin) != NULL) {
++ while (getline(&line, &linelen, stdin) >= 0) {
+ if (signal_received)
+ break;
+- write_line(line);
++
++ if (fputs_careful(line, stdout, '^', true) == EOF)
++ err(EXIT_FAILURE, _("carefulputc failed"));
+ }
++ free(line);
+ printf("EOF\r\n");
+ }
+
diff --git a/debian/rules b/debian/rules
index 83d6b34..716702a 100755
--- a/debian/rules
+++ b/debian/rules
@@ -37,6 +37,9 @@ CONFOPTS += --disable-chfn-chsh
# => bsdmainutils
CONFOPTS += --disable-cal
+# Reduce setgid programs (cf. CVE-2024-28085)
+CONFOPTS += --disable-use-tty-group
+
# Get the list of binary package, except lib* and *-udeb, from
# debian/control instead of hardcoding the list when installing
# bash-completions below.