Date: Wed, 12 Feb 2020 15:32:31 +0000 (UTC) From: Conrad Meyer <cem@FreeBSD.org> To: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: svn commit: r525916 - in head/sysutils/grub2-bhyve: . files Message-ID: <202002121532.01CFWVaP042261@repo.freebsd.org>
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Author: cem (src committer) Date: Wed Feb 12 15:32:31 2020 New Revision: 525916 URL: https://svnweb.freebsd.org/changeset/ports/525916 Log: sysutils/grub2-bhyve: Neutralize privileged guest commands GRUB was designed to run in a trusted environment, where anyone with access to grub2.cfg could also modify grub itself. In grub2-bhyve, we have modified it to run in host context, but interpret the commands of guest grub2.cfg. This means we have to worry about malicious guests. This patch addresses two escalation vectors: font-loading, and the direct 'read', 'write', 'in', and 'out' commands (which read/write arbitrary addresses). Both reported by Reno Robert. Disable font-loading by neutering the command. It is believed to be non- essential and there is at least one buffer overflow in the font loading code. Disable reading and writing host memory and IO ports. It is believed to be non-essential. admbugs: 948 Reported by: Reno Robert <renorobert AT gmail.com> Approved by: bapt MFH: 2010Q1 (bapt) Security: yes Added: head/sysutils/grub2-bhyve/files/patch-grub-core_commands_iorw.c (contents, props changed) head/sysutils/grub2-bhyve/files/patch-grub-core_commands_memrw.c (contents, props changed) head/sysutils/grub2-bhyve/files/patch-grub-core_font_font__cmd.c (contents, props changed) Modified: head/sysutils/grub2-bhyve/Makefile Modified: head/sysutils/grub2-bhyve/Makefile ============================================================================== --- head/sysutils/grub2-bhyve/Makefile Wed Feb 12 15:31:25 2020 (r525915) +++ head/sysutils/grub2-bhyve/Makefile Wed Feb 12 15:32:31 2020 (r525916) @@ -4,7 +4,7 @@ PORTNAME= grub2-bhyve DISTVERSIONPREFIX= v DISTVERSION= 0.40 -PORTREVISION= 7 +PORTREVISION= 8 CATEGORIES= sysutils MAINTAINER= ports@FreeBSD.org Added: head/sysutils/grub2-bhyve/files/patch-grub-core_commands_iorw.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sysutils/grub2-bhyve/files/patch-grub-core_commands_iorw.c Wed Feb 12 15:32:31 2020 (r525916) @@ -0,0 +1,39 @@ +--- grub-core/commands/iorw.c.orig 2015-08-31 22:42:56 UTC ++++ grub-core/commands/iorw.c +@@ -45,6 +45,9 @@ grub_cmd_read (grub_extcmd_context_t ctxt, int argc, c + + if (argc != 1) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected")); ++#if 1 /* BHYVE */ ++ grub_puts_("Reading host IO ports disabled."); ++#else + + addr = grub_strtoul (argv[0], 0, 0); + switch (ctxt->extcmd->cmd->name[sizeof ("in") - 1]) +@@ -70,6 +73,7 @@ grub_cmd_read (grub_extcmd_context_t ctxt, int argc, c + } + else + grub_printf ("0x%x\n", value); ++#endif + + return 0; + } +@@ -84,6 +88,10 @@ grub_cmd_write (grub_command_t cmd, int argc, char **a + if (argc != 2 && argc != 3) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected")); + ++#if 1 /* BHYVE */ ++ grub_puts_("Writing host IO ports disabled."); ++#else ++ + addr = grub_strtoul (argv[0], 0, 0); + value = grub_strtoul (argv[1], 0, 0); + if (argc == 3) +@@ -112,6 +120,7 @@ grub_cmd_write (grub_command_t cmd, int argc, char **a + grub_outb (value, addr); + break; + } ++#endif + + return 0; + } Added: head/sysutils/grub2-bhyve/files/patch-grub-core_commands_memrw.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sysutils/grub2-bhyve/files/patch-grub-core_commands_memrw.c Wed Feb 12 15:32:31 2020 (r525916) @@ -0,0 +1,38 @@ +--- grub-core/commands/memrw.c.orig 2015-08-31 22:42:56 UTC ++++ grub-core/commands/memrw.c +@@ -46,6 +46,9 @@ grub_cmd_read (grub_extcmd_context_t ctxt, int argc, c + if (argc != 1) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected")); + ++#if 1 /* BHYVE */ ++ grub_puts_("Reading host memory disabled."); ++#else + addr = grub_strtoul (argv[0], 0, 0); + switch (ctxt->extcmd->cmd->name[sizeof ("read_") - 1]) + { +@@ -69,6 +72,7 @@ grub_cmd_read (grub_extcmd_context_t ctxt, int argc, c + } + else + grub_printf ("0x%x\n", value); ++#endif + + return 0; + } +@@ -83,6 +87,9 @@ grub_cmd_write (grub_command_t cmd, int argc, char **a + if (argc != 2 && argc != 3) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected")); + ++#if 1 /* BHYVE */ ++ grub_puts_("Writing host memory disabled."); ++#else + addr = grub_strtoul (argv[0], 0, 0); + value = grub_strtoul (argv[1], 0, 0); + if (argc == 3) +@@ -114,6 +121,7 @@ grub_cmd_write (grub_command_t cmd, int argc, char **a + *((volatile grub_uint8_t *) addr) = value; + break; + } ++#endif + + return 0; + } Added: head/sysutils/grub2-bhyve/files/patch-grub-core_font_font__cmd.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sysutils/grub2-bhyve/files/patch-grub-core_font_font__cmd.c Wed Feb 12 15:32:31 2020 (r525916) @@ -0,0 +1,20 @@ +--- grub-core/font/font_cmd.c.orig 2020-02-03 00:11:34 UTC ++++ grub-core/font/font_cmd.c +@@ -28,6 +28,9 @@ loadfont_command (grub_command_t cmd __attribute__ ((u + int argc, + char **args) + { ++#if 1 /* BHYVE */ ++ grub_puts_("Font loading disabled."); ++#else + if (argc == 0) + return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected")); + +@@ -38,6 +41,7 @@ loadfont_command (grub_command_t cmd __attribute__ ((u + return grub_error (GRUB_ERR_BAD_FONT, "invalid font"); + return grub_errno; + } ++#endif + + return GRUB_ERR_NONE; + }
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