99 lines
2.9 KiB
Diff
99 lines
2.9 KiB
Diff
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From 3f13d198679437002df2dd0777a3bca879c0061c Mon Sep 17 00:00:00 2001
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From: Tobias Stoeckmann <tobias@stoeckmann.org>
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Date: Thu, 21 Sep 2023 20:25:55 +0200
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Subject: [PATCH] login: prevent undefined ioctl and tcsetattr calls
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Do not call tcsetattr if tcgetattr fails, because the content of
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tt and ttt is undefined in that case.
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Also do not just warn if ioctl fails, but also avoid calling it again
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after tty has been re-opened.
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I've solved this by setting struct variables to values which cannot be
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valid at this point. If they do have these exact values, then the
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calls will be prevented.
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Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
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Reference:https://github.com/util-linux/util-linux/commit/3f13d198679437002df2dd0777a3bca879c0061c
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Conflict:NA
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---
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login-utils/login.c | 32 ++++++++++++++++++++------------
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1 file changed, 20 insertions(+), 12 deletions(-)
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diff --git a/login-utils/login.c b/login-utils/login.c
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index 31a7adb07..544eab5aa 100644
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--- a/login-utils/login.c
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+++ b/login-utils/login.c
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@@ -177,9 +177,10 @@ static void __attribute__((__noreturn__))
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struct termios ti;
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/* reset echo */
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- tcgetattr(0, &ti);
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- ti.c_lflag |= ECHO;
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- tcsetattr(0, TCSANOW, &ti);
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+ if (tcgetattr(0, &ti) >= 0) {
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+ ti.c_lflag |= ECHO;
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+ tcsetattr(0, TCSANOW, &ti);
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+ }
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_exit(EXIT_SUCCESS); /* %% */
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}
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@@ -513,8 +514,8 @@ static void chown_tty(struct login_context *cxt)
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static void init_tty(struct login_context *cxt)
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{
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struct stat st;
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- struct termios tt, ttt;
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- struct winsize ws;
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+ struct termios tt, ttt = { 0 };
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+ struct winsize ws = { 0 };
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int fd;
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cxt->tty_mode = (mode_t) getlogindefs_num("TTYPERM", TTY_MODE);
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@@ -549,13 +550,18 @@ static void init_tty(struct login_context *cxt)
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/* The TTY size might be reset to 0x0 by the kernel when we close the stdin/stdout/stderr file
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* descriptors so let's save the size now so we can reapply it later */
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- memset(&ws, 0, sizeof(struct winsize));
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- if (ioctl(fd, TIOCGWINSZ, &ws) < 0)
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+ if (ioctl(fd, TIOCGWINSZ, &ws) < 0) {
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syslog(LOG_WARNING, _("TIOCGWINSZ ioctl failed: %m"));
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+ ws.ws_row = 0;
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+ ws.ws_col = 0;
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+ }
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- tcgetattr(fd, &tt);
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- ttt = tt;
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- ttt.c_cflag &= ~HUPCL;
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+ if (tcgetattr(fd, &tt) >= 0) {
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+ ttt = tt;
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+ ttt.c_cflag &= ~HUPCL;
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+ } else {
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+ ttt.c_cflag = HUPCL;
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+ }
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if ((fchown(fd, 0, 0) || fchmod(fd, cxt->tty_mode)) && errno != EROFS) {
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@@ -565,7 +571,8 @@ static void init_tty(struct login_context *cxt)
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}
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/* Kill processes left on this tty */
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- tcsetattr(fd, TCSANOW, &ttt);
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+ if ((ttt.c_cflag & HUPCL) == 0)
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+ tcsetattr(fd, TCSANOW, &ttt);
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/*
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* Let's close file descriptors before vhangup
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@@ -583,7 +590,8 @@ static void init_tty(struct login_context *cxt)
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open_tty(cxt->tty_path);
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/* restore tty modes */
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- tcsetattr(STDIN_FILENO, TCSAFLUSH, &tt);
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+ if ((ttt.c_cflag & HUPCL) == 0)
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+ tcsetattr(STDIN_FILENO, TCSAFLUSH, &tt);
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/* Restore tty size */
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if ((ws.ws_row > 0 || ws.ws_col > 0)
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--
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2.33.0
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