Date: Mon, 14 Sep 2015 09:12:29 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r287776 - stable/10/sys/teken Message-ID: <201509140912.t8E9CTIV067375@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: ed Date: Mon Sep 14 09:12:28 2015 New Revision: 287776 URL: https://svnweb.freebsd.org/changeset/base/287776 Log: MFC r286798 and r286827: Stop parsing digits if the value already exceeds UINT_MAX / 100. There is no need for us to support parsing values that are larger than the maximum terminal window size. In this case that would be the maximum of unsigned short. The problem with parsing larger values is that they can cause integer overflows when adjusting the cursor position, leading to all sorts of failing assertions. MFC r286981 and r287098: Don't truncate cursor arithmetic to 16 bits. When updating the row number when the cursor position escape sequence is issued, we should make sure to store the intermediate result in a 32-bit integer. If we fail to do this, the cursor may be set above the origin region, which is bad. This could cause libteken to crash when INVARIANTS is enabled, due to the strict set of assertions that libteken has. PR: 202326, 202540, 202612 Submitted by: kwcu csie org Modified: stable/10/sys/teken/teken.c stable/10/sys/teken/teken_subr.h Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/teken/teken.c ============================================================================== --- stable/10/sys/teken/teken.c Mon Sep 14 08:36:22 2015 (r287775) +++ stable/10/sys/teken/teken.c Mon Sep 14 09:12:28 2015 (r287776) @@ -29,12 +29,14 @@ #include <sys/cdefs.h> #if defined(__FreeBSD__) && defined(_KERNEL) #include <sys/param.h> +#include <sys/limits.h> #include <sys/lock.h> #include <sys/systm.h> #define teken_assert(x) MPASS(x) #else /* !(__FreeBSD__ && _KERNEL) */ #include <sys/types.h> #include <assert.h> +#include <limits.h> #include <stdint.h> #include <stdio.h> #include <string.h> @@ -405,18 +407,24 @@ teken_state_numbers(teken_t *t, teken_ch teken_assert(t->t_curnum < T_NUMSIZE); if (c >= '0' && c <= '9') { - /* - * Don't do math with the default value of 1 when a - * custom number is inserted. - */ if (t->t_stateflags & TS_FIRSTDIGIT) { + /* First digit. */ t->t_stateflags &= ~TS_FIRSTDIGIT; - t->t_nums[t->t_curnum] = 0; - } else { - t->t_nums[t->t_curnum] *= 10; + t->t_nums[t->t_curnum] = c - '0'; + } else if (t->t_nums[t->t_curnum] < UINT_MAX / 100) { + /* + * There is no need to continue parsing input + * once the value exceeds the size of the + * terminal. It would only allow for integer + * overflows when performing arithmetic on the + * cursor position. + * + * Ignore any further digits if the value is + * already UINT_MAX / 100. + */ + t->t_nums[t->t_curnum] = + t->t_nums[t->t_curnum] * 10 + c - '0'; } - - t->t_nums[t->t_curnum] += c - '0'; return (1); } else if (c == ';') { if (t->t_stateflags & TS_FIRSTDIGIT) Modified: stable/10/sys/teken/teken_subr.h ============================================================================== --- stable/10/sys/teken/teken_subr.h Mon Sep 14 08:36:22 2015 (r287775) +++ stable/10/sys/teken/teken_subr.h Mon Sep 14 09:12:28 2015 (r287776) @@ -324,13 +324,13 @@ static void teken_subr_cursor_position(teken_t *t, unsigned int row, unsigned int col) { - t->t_cursor.tp_row = t->t_originreg.ts_begin + row - 1; - if (t->t_cursor.tp_row >= t->t_originreg.ts_end) - t->t_cursor.tp_row = t->t_originreg.ts_end - 1; - - t->t_cursor.tp_col = col - 1; - if (t->t_cursor.tp_col >= t->t_winsize.tp_col) - t->t_cursor.tp_col = t->t_winsize.tp_col - 1; + row = row - 1 + t->t_originreg.ts_begin; + t->t_cursor.tp_row = row < t->t_originreg.ts_end ? + row : t->t_originreg.ts_end - 1; + + col--; + t->t_cursor.tp_col = col < t->t_winsize.tp_col ? + col : t->t_winsize.tp_col - 1; t->t_stateflags &= ~TS_WRAPPED; teken_funcs_cursor(t); @@ -583,9 +583,9 @@ static void teken_subr_horizontal_position_absolute(teken_t *t, unsigned int col) { - t->t_cursor.tp_col = col - 1; - if (t->t_cursor.tp_col >= t->t_winsize.tp_col) - t->t_cursor.tp_col = t->t_winsize.tp_col - 1; + col--; + t->t_cursor.tp_col = col < t->t_winsize.tp_col ? + col : t->t_winsize.tp_col - 1; t->t_stateflags &= ~TS_WRAPPED; teken_funcs_cursor(t); @@ -1297,9 +1297,9 @@ static void teken_subr_vertical_position_absolute(teken_t *t, unsigned int row) { - t->t_cursor.tp_row = t->t_originreg.ts_begin + row - 1; - if (t->t_cursor.tp_row >= t->t_originreg.ts_end) - t->t_cursor.tp_row = t->t_originreg.ts_end - 1; + row = row - 1 + t->t_originreg.ts_begin; + t->t_cursor.tp_row = row < t->t_originreg.ts_end ? + row : t->t_originreg.ts_end - 1; t->t_stateflags &= ~TS_WRAPPED; teken_funcs_cursor(t);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201509140912.t8E9CTIV067375>