diff options
author | 2012-09-04 13:26:11 -0500 | |
---|---|---|
committer | 2012-09-05 10:38:39 -0500 | |
commit | 113f4cd9e96f55df159573282110848b898e6b50 (patch) | |
tree | f83e7754cdc65766307532748d8bc712a4044772 | |
parent | qemu-timer: properly arm alarm timer for timers set by device initialization (diff) | |
download | qemu-kvm-113f4cd9e96f55df159573282110848b898e6b50.tar.gz qemu-kvm-113f4cd9e96f55df159573282110848b898e6b50.tar.bz2 qemu-kvm-113f4cd9e96f55df159573282110848b898e6b50.zip |
console: bounds check whenever changing the cursor due to an escape code
This is XSA-17 / CVE-2012-3515
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r-- | console.c | 57 |
1 files changed, 28 insertions, 29 deletions
@@ -847,6 +847,26 @@ static void console_clear_xy(TextConsole *s, int x, int y) update_xy(s, x, y); } +/* set cursor, checking bounds */ +static void set_cursor(TextConsole *s, int x, int y) +{ + if (x < 0) { + x = 0; + } + if (y < 0) { + y = 0; + } + if (y >= s->height) { + y = s->height - 1; + } + if (x >= s->width) { + x = s->width - 1; + } + + s->x = x; + s->y = y; +} + static void console_putchar(TextConsole *s, int ch) { TextCell *c; @@ -918,7 +938,8 @@ static void console_putchar(TextConsole *s, int ch) s->esc_params[s->nb_esc_params] * 10 + ch - '0'; } } else { - s->nb_esc_params++; + if (s->nb_esc_params < MAX_ESC_PARAMS) + s->nb_esc_params++; if (ch == ';') break; #ifdef DEBUG_CONSOLE @@ -932,59 +953,37 @@ static void console_putchar(TextConsole *s, int ch) if (s->esc_params[0] == 0) { s->esc_params[0] = 1; } - s->y -= s->esc_params[0]; - if (s->y < 0) { - s->y = 0; - } + set_cursor(s, s->x, s->y - s->esc_params[0]); break; case 'B': /* move cursor down */ if (s->esc_params[0] == 0) { s->esc_params[0] = 1; } - s->y += s->esc_params[0]; - if (s->y >= s->height) { - s->y = s->height - 1; - } + set_cursor(s, s->x, s->y + s->esc_params[0]); break; case 'C': /* move cursor right */ if (s->esc_params[0] == 0) { s->esc_params[0] = 1; } - s->x += s->esc_params[0]; - if (s->x >= s->width) { - s->x = s->width - 1; - } + set_cursor(s, s->x + s->esc_params[0], s->y); break; case 'D': /* move cursor left */ if (s->esc_params[0] == 0) { s->esc_params[0] = 1; } - s->x -= s->esc_params[0]; - if (s->x < 0) { - s->x = 0; - } + set_cursor(s, s->x - s->esc_params[0], s->y); break; case 'G': /* move cursor to column */ - s->x = s->esc_params[0] - 1; - if (s->x < 0) { - s->x = 0; - } + set_cursor(s, s->esc_params[0] - 1, s->y); break; case 'f': case 'H': /* move cursor to row, column */ - s->x = s->esc_params[1] - 1; - if (s->x < 0) { - s->x = 0; - } - s->y = s->esc_params[0] - 1; - if (s->y < 0) { - s->y = 0; - } + set_cursor(s, s->esc_params[1] - 1, s->esc_params[0] - 1); break; case 'J': switch (s->esc_params[0]) { |