packages/flatpak
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix CVE-2021-41133

Browse Source
This commit is contained in:
xingxing 2021-10-20 17:17:20 +08:00
parent 592c9f8795
commit 8f72478963
11 changed files with 750 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

154
backport-0001-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,154 @@
From e26ac7586c392b5eb35ff4609fe232c52523b2cf Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 11:53:23 +0100
Subject: [PATCH] run: Add an errno value to seccomp filters
At the moment, if we block a syscall we always make it fail with EPERM,
but this is risky: user-space libraries can start to use new replacements
for old syscalls at any time, and will often treat EPERM as a fatal error.
For new syscalls, we should make the syscall fail with ENOSYS, which is
indistinguishable from running on an older kernel and will cause fallback
to an older implementation, for example clone3() to clone().
In future we should probably move from EPERM to ENOSYS for some of the
syscalls we already block, but for now keep the status quo.
This is a prerequisite for fixing the vulnerability tracked as
GHSA-67h7-w3jq-vh4q.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/e26ac7586c392b5eb35ff4609fe232c52523b2cf
---
common/flatpak-run.c | 62 +++++++++++++++++++++++++-------------------
1 file changed, 36 insertions(+), 26 deletions(-)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index f48f402..3931820 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2784,61 +2784,63 @@ setup_seccomp (FlatpakBwrap *bwrap,
struct
{
int scall;
+ int errnum;
struct scmp_arg_cmp *arg;
} syscall_blocklist[] = {
/* Block dmesg */
- {SCMP_SYS (syslog)},
+ {SCMP_SYS (syslog), EPERM},
/* Useless old syscall */
- {SCMP_SYS (uselib)},
+ {SCMP_SYS (uselib), EPERM},
/* Don't allow disabling accounting */
- {SCMP_SYS (acct)},
+ {SCMP_SYS (acct), EPERM},
/* 16-bit code is unnecessary in the sandbox, and modify_ldt is a
historic source of interesting information leaks. */
- {SCMP_SYS (modify_ldt)},
+ {SCMP_SYS (modify_ldt), EPERM},
/* Don't allow reading current quota use */
- {SCMP_SYS (quotactl)},
+ {SCMP_SYS (quotactl), EPERM},
/* Don't allow access to the kernel keyring */
- {SCMP_SYS (add_key)},
- {SCMP_SYS (keyctl)},
- {SCMP_SYS (request_key)},
+ {SCMP_SYS (add_key), EPERM},
+ {SCMP_SYS (keyctl), EPERM},
+ {SCMP_SYS (request_key), EPERM},
/* Scary VM/NUMA ops */
- {SCMP_SYS (move_pages)},
- {SCMP_SYS (mbind)},
- {SCMP_SYS (get_mempolicy)},
- {SCMP_SYS (set_mempolicy)},
- {SCMP_SYS (migrate_pages)},
+ {SCMP_SYS (move_pages), EPERM},
+ {SCMP_SYS (mbind), EPERM},
+ {SCMP_SYS (get_mempolicy), EPERM},
+ {SCMP_SYS (set_mempolicy), EPERM},
+ {SCMP_SYS (migrate_pages), EPERM},
/* Don't allow subnamespace setups: */
- {SCMP_SYS (unshare)},
- {SCMP_SYS (mount)},
- {SCMP_SYS (pivot_root)},
+ {SCMP_SYS (unshare), EPERM},
+ {SCMP_SYS (mount), EPERM},
+ {SCMP_SYS (pivot_root), EPERM},
#if defined(__s390__) || defined(__s390x__) || defined(__CRIS__)
/* Architectures with CONFIG_CLONE_BACKWARDS2: the child stack
* and flags arguments are reversed so the flags come second */
- {SCMP_SYS (clone), &SCMP_A1 (SCMP_CMP_MASKED_EQ, CLONE_NEWUSER, CLONE_NEWUSER)},
+ {SCMP_SYS (clone), EPERM, &SCMP_A1 (SCMP_CMP_MASKED_EQ, CLONE_NEWUSER, CLONE_NEWUSER)},
#else
/* Normally the flags come first */
- {SCMP_SYS (clone), &SCMP_A0 (SCMP_CMP_MASKED_EQ, CLONE_NEWUSER, CLONE_NEWUSER)},
+ {SCMP_SYS (clone), EPERM, &SCMP_A0 (SCMP_CMP_MASKED_EQ, CLONE_NEWUSER, CLONE_NEWUSER)},
#endif
/* Don't allow faking input to the controlling tty (CVE-2017-5226) */
- {SCMP_SYS (ioctl), &SCMP_A1 (SCMP_CMP_MASKED_EQ, 0xFFFFFFFFu, (int) TIOCSTI)},
+ {SCMP_SYS (ioctl), EPERM, &SCMP_A1 (SCMP_CMP_MASKED_EQ, 0xFFFFFFFFu, (int) TIOCSTI)},
};
struct
{
int scall;
+ int errnum;
struct scmp_arg_cmp *arg;
} syscall_nondevel_blocklist[] = {
/* Profiling operations; we expect these to be done by tools from outside
* the sandbox. In particular perf has been the source of many CVEs.
*/
- {SCMP_SYS (perf_event_open)},
+ {SCMP_SYS (perf_event_open), EPERM},
/* Don't allow you to switch to bsd emulation or whatnot */
- {SCMP_SYS (personality), &SCMP_A0 (SCMP_CMP_NE, allowed_personality)},
- {SCMP_SYS (ptrace)}
+ {SCMP_SYS (personality), EPERM, &SCMP_A0 (SCMP_CMP_NE, allowed_personality)},
+ {SCMP_SYS (ptrace), EPERM}
};
/* Blocklist all but unix, inet, inet6 and netlink */
struct
@@ -2922,10 +2924,14 @@ setup_seccomp (FlatpakBwrap *bwrap,
for (i = 0; i < G_N_ELEMENTS (syscall_blocklist); i++)
{
int scall = syscall_blocklist[i].scall;
+ int errnum = syscall_blocklist[i].errnum;
+
+ g_return_val_if_fail (errnum == EPERM || errnum == ENOSYS, FALSE);
+
if (syscall_blocklist[i].arg)
- r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (EPERM), scall, 1, *syscall_blocklist[i].arg);
+ r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 1, *syscall_blocklist[i].arg);
else
- r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (EPERM), scall, 0);
+ r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 0);
if (r < 0 && r == -EFAULT /* unknown syscall */)
return flatpak_fail_error (error, FLATPAK_ERROR_SETUP_FAILED, _("Failed to block syscall %d"), scall);
}
@@ -2935,10 +2941,14 @@ setup_seccomp (FlatpakBwrap *bwrap,
for (i = 0; i < G_N_ELEMENTS (syscall_nondevel_blocklist); i++)
{
int scall = syscall_nondevel_blocklist[i].scall;
+ int errnum = syscall_nondevel_blocklist[i].errnum;
+
+ g_return_val_if_fail (errnum == EPERM || errnum == ENOSYS, FALSE);
+
if (syscall_nondevel_blocklist[i].arg)
- r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (EPERM), scall, 1, *syscall_nondevel_blocklist[i].arg);
+ r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 1, *syscall_nondevel_blocklist[i].arg);
else
- r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (EPERM), scall, 0);
+ r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 0);
if (r < 0 && r == -EFAULT /* unknown syscall */)
return flatpak_fail_error (error, FLATPAK_ERROR_SETUP_FAILED, _("Failed to block syscall %d"), scall);
--
2.27.0

33
backport-0002-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,33 @@
From 89ae9fe74c6d445bb1b3a40e568d77cf5de47e48 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 12:44:04 +0100
Subject: [PATCH] run: Add cross-references for some other seccomp syscall
filters
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/89ae9fe74c6d445bb1b3a40e568d77cf5de47e48
---
common/flatpak-run.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index 3931820..38ba16f 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2779,6 +2779,10 @@ setup_seccomp (FlatpakBwrap *bwrap,
* https://git.gnome.org/browse/linux-user-chroot
* in src/setup-seccomp.c
*
+ * Other useful resources:
+ * https://github.com/systemd/systemd/blob/HEAD/src/shared/seccomp-util.c
+ * https://github.com/moby/moby/blob/HEAD/profiles/seccomp/default.json
+ *
**** END NOTE ON CODE SHARING
*/
struct
--
2.27.0

252
backport-0003-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,252 @@
From 26b12484eb8a6219b9e7aa287b298a894b2f34ca Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 14:17:04 +0100
Subject: [PATCH] common: Add a list of recently-added Linux syscalls
Historically, syscalls could take arbitrarily-different values on
different architectures, but new syscalls are added with syscall numbers
that align on each architecture.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/26b12484eb8a6219b9e7aa287b298a894b2f34ca
---
common/Makefile.am.inc | 1 +
common/flatpak-run.c | 2 +
common/flatpak-syscalls-private.h | 197 ++++++++++++++++++++++++++++++
3 files changed, 200 insertions(+)
create mode 100644 common/flatpak-syscalls-private.h
diff --git a/common/Makefile.am.inc b/common/Makefile.am.inc
index b681294..919b015 100644
--- a/common/Makefile.am.inc
+++ b/common/Makefile.am.inc
@@ -160,6 +160,7 @@ libflatpak_common_la_SOURCES = \
common/flatpak-remote.c \
common/flatpak-run-private.h \
common/flatpak-run.c \
+ common/flatpak-syscalls-private.h \
common/flatpak-transaction-private.h \
common/flatpak-transaction.c \
common/flatpak-transaction.h \
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index 38ba16f..5cf6d2e 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -41,6 +41,8 @@
#include <libmalcontent/malcontent.h>
#endif
+#include "flatpak-syscalls-private.h"
+
#ifdef ENABLE_SECCOMP
#include <seccomp.h>
#endif
diff --git a/common/flatpak-syscalls-private.h b/common/flatpak-syscalls-private.h
new file mode 100644
index 0000000..04eb38c
--- /dev/null
+++ b/common/flatpak-syscalls-private.h
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2021 Collabora Ltd.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <sys/syscall.h>
+
+#if defined(_MIPS_SIM)
+# if _MIPS_SIM == _MIPS_SIM_ABI32
+# define FLATPAK_MISSING_SYSCALL_BASE 4000
+# elif _MIPS_SIM == _MIPS_SIM_ABI64
+# define FLATPAK_MISSING_SYSCALL_BASE 5000
+# elif _MIPS_SIM == _MIPS_SIM_NABI32
+# define FLATPAK_MISSING_SYSCALL_BASE 6000
+# else
+# error "Unknown MIPS ABI"
+# endif
+#endif
+
+#if defined(__ia64__)
+# define FLATPAK_MISSING_SYSCALL_BASE 1024
+#endif
+
+#if defined(__alpha__)
+# define FLATPAK_MISSING_SYSCALL_BASE 110
+#endif
+
+#if defined(__x86_64__) && defined(__ILP32__)
+# define FLATPAK_MISSING_SYSCALL_BASE 0x40000000
+#endif
+
+/*
+ * FLATPAK_MISSING_SYSCALL_BASE:
+ *
+ * Number to add to the syscall numbers of recently-added syscalls
+ * to get the appropriate syscall for the current ABI.
+ */
+#ifndef FLATPAK_MISSING_SYSCALL_BASE
+# define FLATPAK_MISSING_SYSCALL_BASE 0
+#endif
+
+#ifndef __NR_open_tree
+# define __NR_open_tree (FLATPAK_MISSING_SYSCALL_BASE + 428)
+#endif
+#ifndef __SNR_open_tree
+# define __SNR_open_tree __NR_open_tree
+#endif
+
+#ifndef __NR_move_mount
+# define __NR_move_mount (FLATPAK_MISSING_SYSCALL_BASE + 429)
+#endif
+#ifndef __SNR_move_mount
+# define __SNR_move_mount __NR_move_mount
+#endif
+
+#ifndef __NR_fsopen
+# define __NR_fsopen (FLATPAK_MISSING_SYSCALL_BASE + 430)
+#endif
+#ifndef __SNR_fsopen
+# define __SNR_fsopen __NR_fsopen
+#endif
+
+#ifndef __NR_fsconfig
+# define __NR_fsconfig (FLATPAK_MISSING_SYSCALL_BASE + 431)
+#endif
+#ifndef __SNR_fsconfig
+# define __SNR_fsconfig __NR_fsconfig
+#endif
+
+#ifndef __NR_fsmount
+# define __NR_fsmount (FLATPAK_MISSING_SYSCALL_BASE + 432)
+#endif
+#ifndef __SNR_fsmount
+# define __SNR_fsmount __NR_fsmount
+#endif
+
+#ifndef __NR_fspick
+# define __NR_fspick (FLATPAK_MISSING_SYSCALL_BASE + 433)
+#endif
+#ifndef __SNR_fspick
+# define __SNR_fspick __NR_fspick
+#endif
+
+#ifndef __NR_pidfd_open
+# define __NR_pidfd_open (FLATPAK_MISSING_SYSCALL_BASE + 434)
+#endif
+#ifndef __SNR_pidfd_open
+# define __SNR_pidfd_open __NR_pidfd_open
+#endif
+
+#ifndef __NR_clone3
+# define __NR_clone3 (FLATPAK_MISSING_SYSCALL_BASE + 435)
+#endif
+#ifndef __SNR_clone3
+# define __SNR_clone3 __NR_clone3
+#endif
+
+#ifndef __NR_close_range
+# define __NR_close_range (FLATPAK_MISSING_SYSCALL_BASE + 436)
+#endif
+#ifndef __SNR_close_range
+# define __SNR_close_range __NR_close_range
+#endif
+
+#ifndef __NR_openat2
+# define __NR_openat2 (FLATPAK_MISSING_SYSCALL_BASE + 437)
+#endif
+#ifndef __SNR_openat2
+# define __SNR_openat2 __NR_openat2
+#endif
+
+#ifndef __NR_pidfd_getfd
+# define __NR_pidfd_getfd (FLATPAK_MISSING_SYSCALL_BASE + 438)
+#endif
+#ifndef __SNR_pidfd_getfd
+# define __SNR_pidfd_getfd __NR_pidfd_getfd
+#endif
+
+#ifndef __NR_faccessat2
+# define __NR_faccessat2 (FLATPAK_MISSING_SYSCALL_BASE + 439)
+#endif
+#ifndef __SNR_faccessat2
+# define __SNR_faccessat2 __NR_faccessat2
+#endif
+
+#ifndef __NR_process_madvise
+# define __NR_process_madvise (FLATPAK_MISSING_SYSCALL_BASE + 440)
+#endif
+#ifndef __SNR_process_madvise
+# define __SNR_process_madvise __NR_process_madvise
+#endif
+
+#ifndef __NR_epoll_pwait2
+# define __NR_epoll_pwait2 (FLATPAK_MISSING_SYSCALL_BASE + 441)
+#endif
+#ifndef __SNR_epoll_pwait2
+# define __SNR_epoll_pwait2 __NR_epoll_pwait2
+#endif
+
+#ifndef __NR_mount_setattr
+# define __NR_mount_setattr (FLATPAK_MISSING_SYSCALL_BASE + 442)
+#endif
+#ifndef __SNR_mount_setattr
+# define __SNR_mount_setattr __NR_mount_setattr
+#endif
+
+#ifndef __NR_quotactl_fd
+# define __NR_quotactl_fd (FLATPAK_MISSING_SYSCALL_BASE + 443)
+#endif
+#ifndef __SNR_quotactl_fd
+# define __SNR_quotactl_fd __NR_quotactl_fd
+#endif
+
+#ifndef __NR_landlock_create_ruleset
+# define __NR_landlock_create_ruleset (FLATPAK_MISSING_SYSCALL_BASE + 444)
+#endif
+#ifndef __SNR_landlock_create_ruleset
+# define __SNR_landlock_create_ruleset __NR_landlock_create_ruleset
+#endif
+
+#ifndef __NR_landlock_add_rule
+# define __NR_landlock_add_rule (FLATPAK_MISSING_SYSCALL_BASE + 445)
+#endif
+#ifndef __SNR_landlock_add_rule
+# define __SNR_landlock_add_rule __NR_landlock_add_rule
+#endif
+
+#ifndef __NR_landlock_restrict_self
+# define __NR_landlock_restrict_self (FLATPAK_MISSING_SYSCALL_BASE + 446)
+#endif
+#ifndef __SNR_landlock_restrict_self
+# define __SNR_landlock_restrict_self __NR_landlock_restrict_self
+#endif
+
+#ifndef __NR_memfd_secret
+# define __NR_memfd_secret (FLATPAK_MISSING_SYSCALL_BASE + 447)
+#endif
+#ifndef __SNR_memfd_secret
+# define __SNR_memfd_secret __NR_memfd_secret
+#endif
+
+/* Last updated: Linux 5.14, syscall numbers < 448 */
--
2.27.0

43
backport-0004-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,43 @@
From a10f52a7565c549612c92b8e736a6698a53db330 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 11:59:00 +0100
Subject: [PATCH] run: Block clone3() in sandbox
clone3() can be used to implement clone() with CLONE_NEWUSER, allowing
a sandboxed process to get CAP_SYS_ADMIN in a new namespace and
manipulate its root directory. We need to block this so that AF_UNIX-based
socket servers (X11, Wayland, etc.) can rely on
/proc/PID/root/.flatpak-info existing for all Flatpak-sandboxed apps.
Partially fixes GHSA-67h7-w3jq-vh4q.
Thanks: an anonymous reporter
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/a10f52a7565c549612c92b8e736a6698a53db330
---
common/flatpak-run.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index 5cf6d2e..dad0cfe 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2832,6 +2832,12 @@ setup_seccomp (FlatpakBwrap *bwrap,
/* Don't allow faking input to the controlling tty (CVE-2017-5226) */
{SCMP_SYS (ioctl), EPERM, &SCMP_A1 (SCMP_CMP_MASKED_EQ, 0xFFFFFFFFu, (int) TIOCSTI)},
+
+ /* seccomp can't look into clone3()'s struct clone_args to check whether
+ * the flags are OK, so we have no choice but to block clone3().
+ * Return ENOSYS so user-space will fall back to clone().
+ * (GHSA-67h7-w3jq-vh4q; see also https://github.com/moby/moby/commit/9f6b562d) */
+ {SCMP_SYS (clone3), ENOSYS},
};
struct
--
2.27.0

45
backport-0005-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,45 @@
From 9766ee05b1425db397d2cf23afd24c7f6146a69f Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 12:45:54 +0100
Subject: [PATCH] run: Disallow recently-added mount-manipulation syscalls
If we don't allow mount() then we shouldn't allow these either.
Partially fixes GHSA-67h7-w3jq-vh4q.
Thanks: an anonymous reporter
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/9766ee05b1425db397d2cf23afd24c7f6146a69f
---
common/flatpak-run.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index dad0cfe..2781694 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2838,6 +2838,18 @@ setup_seccomp (FlatpakBwrap *bwrap,
* Return ENOSYS so user-space will fall back to clone().
* (GHSA-67h7-w3jq-vh4q; see also https://github.com/moby/moby/commit/9f6b562d) */
{SCMP_SYS (clone3), ENOSYS},
+
+ /* New mount manipulation APIs can also change our VFS. There's no
+ * legitimate reason to do these in the sandbox, so block all of them
+ * rather than thinking about which ones might be dangerous.
+ * (GHSA-67h7-w3jq-vh4q) */
+ {SCMP_SYS (open_tree), ENOSYS},
+ {SCMP_SYS (move_mount), ENOSYS},
+ {SCMP_SYS (fsopen), ENOSYS},
+ {SCMP_SYS (fsconfig), ENOSYS},
+ {SCMP_SYS (fsmount), ENOSYS},
+ {SCMP_SYS (fspick), ENOSYS},
+ {SCMP_SYS (mount_setattr), ENOSYS},
};
struct
--
2.27.0

34
backport-0006-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,34 @@
From 4c34815784e9ffda5733225c7d95824f96375e36 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 14:19:31 +0100
Subject: [PATCH] run: Block setns()
If we don't allow unshare() or clone() with CLONE_NEWUSER, we also
shouldn't allow joining an existing (but different) namespace.
Partially fixes GHSA-67h7-w3jq-vh4q.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/4c34815784e9ffda5733225c7d95824f96375e36
---
common/flatpak-run.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index 2781694..c266dbe 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2819,6 +2819,7 @@ setup_seccomp (FlatpakBwrap *bwrap,
/* Don't allow subnamespace setups: */
{SCMP_SYS (unshare), EPERM},
+ {SCMP_SYS (setns), EPERM},
{SCMP_SYS (mount), EPERM},
{SCMP_SYS (pivot_root), EPERM},
#if defined(__s390__) || defined(__s390x__) || defined(__CRIS__)
--
2.27.0

35
backport-0007-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,35 @@
From 1330662f33a55e88bfe18e76de28b7922d91a999 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 14:20:29 +0100
Subject: [PATCH] run: Don't allow unmounting filesystems
If we don't allow mounting filesystems, we shouldn't allow unmounting
either.
Partially fixes GHSA-67h7-w3jq-vh4q.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/1330662f33a55e88bfe18e76de28b7922d91a999
---
common/flatpak-run.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index c266dbe..b1a8db5 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2821,6 +2821,8 @@ setup_seccomp (FlatpakBwrap *bwrap,
{SCMP_SYS (unshare), EPERM},
{SCMP_SYS (setns), EPERM},
{SCMP_SYS (mount), EPERM},
+ {SCMP_SYS (umount), EPERM},
+ {SCMP_SYS (umount2), EPERM},
{SCMP_SYS (pivot_root), EPERM},
#if defined(__s390__) || defined(__s390x__) || defined(__CRIS__)
/* Architectures with CONFIG_CLONE_BACKWARDS2: the child stack
--
2.27.0

34
backport-0008-CVE-2021-41133.patch Normal file
View File

@ -0,0 +1,34 @@
From 462fca2c666e0cd2b60d6d2593a7216a83047aaf Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Wed, 1 Sep 2021 14:21:04 +0100
Subject: [PATCH] run: Don't allow chroot()
If we don't allow pivot_root() then there seems no reason why we should
allow chroot().
Partially fixes GHSA-67h7-w3jq-vh4q.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/462fca2c666e0cd2b60d6d2593a7216a83047aaf
---
common/flatpak-run.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index b1a8db5..da96465 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2824,6 +2824,7 @@ setup_seccomp (FlatpakBwrap *bwrap,
{SCMP_SYS (umount), EPERM},
{SCMP_SYS (umount2), EPERM},
{SCMP_SYS (pivot_root), EPERM},
+ {SCMP_SYS (chroot), EPERM},
#if defined(__s390__) || defined(__s390x__) || defined(__CRIS__)
/* Architectures with CONFIG_CLONE_BACKWARDS2: the child stack
* and flags arguments are reversed so the flags come second */
--
2.27.0

33
backport-Fix-handling-of-syscalls-only-allowed-by-de.patch Normal file
View File

@ -0,0 +1,33 @@
From 3fc8c672676ae016f8e7cc90481b2feecbad9861 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Fri, 8 Oct 2021 19:00:13 +0100
Subject: [PATCH] Fix handling of syscalls only allowed by --devel
This was incorrectly looking at errno instead of -r.
Fixes: 0b38b0f0 "run: Handle unknown syscalls as intended"
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/3fc8c672676ae016f8e7cc90481b2feecbad9861
---
common/flatpak-run.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index a416f1b..69eabc0 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2988,7 +2988,7 @@ setup_seccomp (FlatpakBwrap *bwrap,
r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 0);
/* See above for the meaning of EFAULT. */
- if (errno == EFAULT)
+ if (r == -EFAULT)
flatpak_debug2 ("Unable to block syscall %d: syscall not known to libseccomp?",
scall);
else if (r < 0)
--
2.27.0

73
backport-run-Handle-unknown-syscalls-as-intended.patch Normal file
View File

@ -0,0 +1,73 @@
From d419fa67038370e4f4c3ce8c3b5f672d4876cfc8 Mon Sep 17 00:00:00 2001
From: Simon McVittie <smcv@collabora.com>
Date: Fri, 8 Oct 2021 17:05:07 +0100
Subject: [PATCH] run: Handle unknown syscalls as intended
The error-handling here was
if (r < 0 && r == -EFAULT)
but Alex says it was almost certainly intended to be
if (r < 0 && r != -EFAULT)
so that syscalls not known to libseccomp are not a fatal error.
Instead of literally making that change, emit a debug message on -EFAULT
so we can see what is going on.
This temporarily weakens our defence against CVE-2021-41133
(GHSA-67h7-w3jq-vh4q) in order to avoid regressions: if the installed
version of libseccomp does not know about the recently-added syscalls,
but the kernel does, then we will not prevent non-native executables
from using those syscalls.
Resolves: https://github.com/flatpak/flatpak/issues/4458
Signed-off-by: Simon McVittie <smcv@collabora.com>
Conflict:NA
Reference:https://github.com/flatpak/flatpak/commit/d419fa67038370e4f4c3ce8c3b5f672d4876cfc8
---
common/flatpak-run.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/common/flatpak-run.c b/common/flatpak-run.c
index da96465..a416f1b 100644
--- a/common/flatpak-run.c
+++ b/common/flatpak-run.c
@@ -2960,7 +2960,16 @@ setup_seccomp (FlatpakBwrap *bwrap,
r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 1, *syscall_blocklist[i].arg);
else
r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 0);
- if (r < 0 && r == -EFAULT /* unknown syscall */)
+
+ /* EFAULT means "internal libseccomp error", but in practice we get
+ * this for syscall numbers added via flatpak-syscalls-private.h
+ * when trying to filter them on a non-native architecture, because
+ * libseccomp cannot map the syscall number to a name and back to a
+ * number for the non-native architecture. */
+ if (r == -EFAULT)
+ flatpak_debug2 ("Unable to block syscall %d: syscall not known to libseccomp?",
+ scall);
+ else if (r < 0)
return flatpak_fail_error (error, FLATPAK_ERROR_SETUP_FAILED, _("Failed to block syscall %d"), scall);
}
@@ -2978,7 +2987,11 @@ setup_seccomp (FlatpakBwrap *bwrap,
else
r = seccomp_rule_add (seccomp, SCMP_ACT_ERRNO (errnum), scall, 0);
- if (r < 0 && r == -EFAULT /* unknown syscall */)
+ /* See above for the meaning of EFAULT. */
+ if (errno == EFAULT)
+ flatpak_debug2 ("Unable to block syscall %d: syscall not known to libseccomp?",
+ scall);
+ else if (r < 0)
return flatpak_fail_error (error, FLATPAK_ERROR_SETUP_FAILED, _("Failed to block syscall %d"), scall);
}
}
--
2.27.0

15
flatpak.spec
View File

@ -1,6 +1,6 @@
Name: flatpak
Version: 1.10.2
Release: 1
Release: 2
Summary: Application deployment framework for desktop apps
License: LGPLv2+
URL: http://flatpak.org/
@ -9,6 +9,16 @@ Patch0000: modify-automake-version.patch
Patch0002: CVE-2021-21261-2.patch
Patch0004: CVE-2021-21261-4.patch
Patch0005: 0001-OCI-Switch-to-pax-format-for-tar-archives.patch
Patch6000: backport-0001-CVE-2021-41133.patch
Patch6001: backport-0002-CVE-2021-41133.patch
Patch6002: backport-0003-CVE-2021-41133.patch
Patch6003: backport-0004-CVE-2021-41133.patch
Patch6004: backport-0005-CVE-2021-41133.patch
Patch6005: backport-0006-CVE-2021-41133.patch
Patch6006: backport-0007-CVE-2021-41133.patch
Patch6007: backport-0008-CVE-2021-41133.patch
Patch6008: backport-run-Handle-unknown-syscalls-as-intended.patch
Patch6009: backport-Fix-handling-of-syscalls-only-allowed-by-de.patch
BuildRequires: pkgconfig(appstream-glib) pkgconfig(gio-unix-2.0) pkgconfig(gobject-introspection-1.0) >= 1.40.0 pkgconfig(json-glib-1.0) pkgconfig(libarchive) >= 2.8.0
BuildRequires: pkgconfig(libsoup-2.4) pkgconfig(libxml-2.0) >= 2.4 pkgconfig(ostree-1) >= 2020.8 pkgconfig(polkit-gobject-1) pkgconfig(libseccomp) pkgconfig(xau)
@ -114,6 +124,9 @@ flatpak remote-list --system &> /dev/null || :
%{_mandir}/man5/flatpak-remote.5*
%changelog
* Thu Oct 21 2021 xingxing <xingxing9@huawei.com> - 1.10.2-2
- Fix CVE-2021-41133
* Tue Jun 29 2021 weijin deng <weijin.deng@turbolinux.com.cn> - 1.10.2-1
- Upgrade to 1.10.2
- Delete patches that existed in this version 1.10.2, delete sed option