We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SECCOMP_RET_KILL filter return code has always killed the current
thread, not the entire process. Changing this as a side-effect of dumping
core isn't a safe thing to do (a few test suites have already flagged this
behavioral change). Instead, restore the RET_KILL semantics, but still
dump core when a RET_KILL delivers SIGSYS to a single-threaded process.
Fixes: b25e67161c ("seccomp: dump core when using SECCOMP_RET_KILL")
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The SECCOMP_RET_KILL mode is documented as immediately killing the
process as if a SIGSYS had been sent and not caught (similar to a
SIGKILL). However, a SIGSYS is documented as triggering a coredump
which does not happen today.
This has the advantage of being able to more easily debug a process
that fails a seccomp filter. Today, most apps need to recompile and
change their filter in order to get detailed info out, or manually run
things through strace, or enable detailed kernel auditing. Now we get
coredumps that fit into existing system-wide crash reporting setups.
From a security pov, this shouldn't be a problem. Unhandled signals
can already be sent externally which trigger a coredump independent of
the status of the seccomp filter. The act of dumping core itself does
not cause change in execution of the program.
URL: https://crbug.com/676357
Signed-off-by: Mike Frysinger <vapier@chromium.org>
Acked-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Pull security subsystem updates from James Morris:
"Generally pretty quiet for this release. Highlights:
Yama:
- allow ptrace access for original parent after re-parenting
TPM:
- add documentation
- many bugfixes & cleanups
- define a generic open() method for ascii & bios measurements
Integrity:
- Harden against malformed xattrs
SELinux:
- bugfixes & cleanups
Smack:
- Remove unnecessary smack_known_invalid label
- Do not apply star label in smack_setprocattr hook
- parse mnt opts after privileges check (fixes unpriv DoS vuln)"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (56 commits)
Yama: allow access for the current ptrace parent
tpm: adjust return value of tpm_read_log
tpm: vtpm_proxy: conditionally call tpm_chip_unregister
tpm: Fix handling of missing event log
tpm: Check the bios_dir entry for NULL before accessing it
tpm: return -ENODEV if np is not set
tpm: cleanup of printk error messages
tpm: replace of_find_node_by_name() with dev of_node property
tpm: redefine read_log() to handle ACPI/OF at runtime
tpm: fix the missing .owner in tpm_bios_measurements_ops
tpm: have event log use the tpm_chip
tpm: drop tpm1_chip_register(/unregister)
tpm: replace dynamically allocated bios_dir with a static array
tpm: replace symbolic permission with octal for securityfs files
char: tpm: fix kerneldoc tpm2_unseal_trusted name typo
tpm_tis: Allow tpm_tis to be bound using DT
tpm, tpm_vtpm_proxy: add kdoc comments for VTPM_PROXY_IOC_NEW_DEV
tpm: Only call pm_runtime_get_sync if device has a parent
tpm: define a generic open() method for ascii & bios measurements
Documentation: tpm: add the Physical TPM device tree binding documentation
...
Since long already bpf_func is not only about struct sk_buff * as
input anymore. Make it generic as void *, so that callers don't
need to cast for it each time they call BPF_PROG_RUN().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes a ptrace vs fatal pending signals bug as manifested in
seccomp now that seccomp was reordered to happen after ptrace. The
short version is that seccomp should not attempt to call do_exit()
while fatal signals are pending under a tracer. The existing code was
trying to be as defensively paranoid as possible, but it now ends up
confusing ptrace. Instead, the syscall can just be skipped (which solves
the original concern that the do_exit() was addressing) and normal signal
handling, tracer notification, and process death can happen.
Paraphrasing from the original bug report:
If a tracee task is in a PTRACE_EVENT_SECCOMP trap, or has been resumed
after such a trap but not yet been scheduled, and another task in the
thread-group calls exit_group(), then the tracee task exits without the
ptracer receiving a PTRACE_EVENT_EXIT notification. Test case here:
https://gist.github.com/khuey/3c43ac247c72cef8c956ca73281c9be7
The bug happens because when __seccomp_filter() detects
fatal_signal_pending(), it calls do_exit() without dequeuing the fatal
signal. When do_exit() sends the PTRACE_EVENT_EXIT notification and
that task is descheduled, __schedule() notices that there is a fatal
signal pending and changes its state from TASK_TRACED to TASK_RUNNING.
That prevents the ptracer's waitpid() from returning the ptrace event.
A more detailed analysis is here:
https://github.com/mozilla/rr/issues/1762#issuecomment-237396255.
Reported-by: Robert O'Callahan <robert@ocallahan.org>
Reported-by: Kyle Huey <khuey@kylehuey.com>
Tested-by: Kyle Huey <khuey@kylehuey.com>
Fixes: 93e35efb8d ("x86/ptrace: run seccomp after ptrace")
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
When RET_TRACE triggers, a tracer may change a syscall into something that
should be filtered by seccomp. This re-runs seccomp after a trace event
to make sure things continue to pass.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Since nothing is using the 2-phase API, and it adds more complexity than
benefit, remove it.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Currently, if arch code wants to supply seccomp_data directly to
seccomp (which is generally much faster than having seccomp do it
using the syscall_get_xyz() API), it has to use the two-phase
seccomp hooks. Add it to the easy hooks, too.
Cc: linux-arch@vger.kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.7. Here's the summary of
the changes:
- ATH79: Support for DTB passuing using the UHI boot protocol
- ATH79: Remove support for builtin DTB.
- ATH79: Add zboot debug serial support.
- ATH79: Add initial support for Dragino MS14 (Dragine 2), Onion Omega
and DPT-Module.
- ATH79: Update devicetree clock support for AR9132 and AR9331.
- ATH79: Cleanup the DT code.
- ATH79: Support newer SOCs in ath79_ddr_ctrl_init.
- ATH79: Fix regression in PCI window initialization.
- BCM47xx: Move SPROM driver to drivers/firmware/
- BCM63xx: Enable partition parser in defconfig.
- BMIPS: BMIPS5000 has I cache filing from D cache
- BMIPS: BMIPS: Add cpu-feature-overrides.h
- BMIPS: Add Whirlwind support
- BMIPS: Adjust mips-hpt-frequency for BCM7435
- BMIPS: Remove maxcpus from BCM97435SVMB DTS
- BMIPS: Add missing 7038 L1 register cells to BCM7435
- BMIPS: Various tweaks to initialization code.
- BMIPS: Enable partition parser in defconfig.
- BMIPS: Cache tweaks.
- BMIPS: Add UART, I2C and SATA devices to DT.
- BMIPS: Add BCM6358 and BCM63268support
- BMIPS: Add device tree example for BCM6358.
- BMIPS: Improve Improve BCM6328 and BCM6368 device trees
- Lantiq: Add support for device tree file from boot loader
- Lantiq: Allow build with no built-in DT.
- Loongson 3: Reserve 32MB for RS780E integrated GPU.
- Loongson 3: Fix build error after ld-version.sh modification
- Loongson 3: Move chipset ACPI code from drivers to arch.
- Loongson 3: Speedup irq processing.
- Loongson 3: Add basic Loongson 3A support.
- Loongson 3: Set cache flush handlers to nop.
- Loongson 3: Invalidate special TLBs when needed.
- Loongson 3: Fast TLB refill handler.
- MT7620: Fallback strategy for invalid syscfg0.
- Netlogic: Fix CP0_EBASE redefinition warnings
- Octeon: Initialization fixes
- Octeon: Add DTS files for the D-Link DSR-1000N and EdgeRouter Lite
- Octeon: Enable add Octeon-drivers in cavium_octeon_defconfig
- Octeon: Correctly handle endian-swapped initramfs images.
- Octeon: Support CN73xx, CN75xx and CN78xx.
- Octeon: Remove dead code from cvmx-sysinfo.
- Octeon: Extend number of supported CPUs past 32.
- Octeon: Remove some code limiting NR_IRQS to 255.
- Octeon: Simplify octeon_irq_ciu_gpio_set_type.
- Octeon: Mark some functions __init in smp.c
- Octeon: Octeon: Add Octeon III CN7xxx interface detection
- PIC32: Add serial driver and bindings for it.
- PIC32: Add PIC32 deadman timer driver and bindings.
- PIC32: Add PIC32 clock timer driver and bindings.
- Pistachio: Determine SoC revision during boot
- Sibyte: Fix Kconfig dependencies of SIBYTE_BUS_WATCHER.
- Sibyte: Strip redundant comments from bcm1480_regs.h.
- Panic immediately if panic_on_oops is set.
- module: fix incorrect IS_ERR_VALUE macro usage.
- module: Make consistent use of pr_*
- Remove no longer needed work_on_cpu() call.
- Remove CONFIG_IPV6_PRIVACY from defconfigs.
- Fix registers of non-crashing CPUs in dumps.
- Handle MIPSisms in new vmcore_elf32_check_arch.
- Select CONFIG_HANDLE_DOMAIN_IRQ and make it work.
- Allow RIXI to be used on non-R2 or R6 cores.
- Reserve nosave data for hibernation
- Fix siginfo.h to use strict POSIX types.
- Don't unwind user mode with EVA.
- Fix watchpoint restoration
- Ptrace watchpoints for R6.
- Sync icache when it fills from dcache
- I6400 I-cache fills from dcache.
- Various MSA fixes.
- Cleanup MIPS_CPU_* definitions.
- Signal: Move generic copy_siginfo to signal.h
- Signal: Fix uapi include in exported asm/siginfo.h
- Timer fixes for sake of KVM.
- XPA TLB refill fixes.
- Treat perf counter feature
- Update John Crispin's email address
- Add PIC32 watchdog and bindings.
- Handle R10000 LL/SC bug in set_pte()
- cpufreq: Various fixes for Longson1.
- R6: Fix R2 emulation.
- mathemu: Cosmetic fix to ADDIUPC emulation, plenty of other small fixes
- ELF: ABI and FP fixes.
- Allow for relocatable kernel and use that to support KASLR.
- Fix CPC_BASE_ADDR mask
- Plenty fo smp-cps, CM, R6 and M6250 fixes.
- Make reset_control_ops const.
- Fix kernel command line handling of leading whitespace.
- Cleanups to cache handling.
- Add brcm, bcm6345-l1-intc device tree bindings.
- Use generic clkdev.h header
- Remove CLK_IS_ROOT usage.
- Misc small cleanups.
- CM: Fix compilation error when !MIPS_CM
- oprofile: Fix a preemption issue
- Detect DSP ASE v3 support:1"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (275 commits)
MIPS: pic32mzda: fix getting timer clock rate.
MIPS: ath79: fix regression in PCI window initialization
MIPS: ath79: make ath79_ddr_ctrl_init() compatible for newer SoCs
MIPS: Fix VZ probe gas errors with binutils <2.24
MIPS: perf: Fix I6400 event numbers
MIPS: DEC: Export `ioasic_ssr_lock' to modules
MIPS: MSA: Fix a link error on `_init_msa_upper' with older GCC
MIPS: CM: Fix compilation error when !MIPS_CM
MIPS: Fix genvdso error on rebuild
USB: ohci-jz4740: Remove obsolete driver
MIPS: JZ4740: Probe OHCI platform device via DT
MIPS: JZ4740: Qi LB60: Remove support for AVT2 variant
MIPS: pistachio: Determine SoC revision during boot
MIPS: BMIPS: Adjust mips-hpt-frequency for BCM7435
mips: mt7620: fallback to SDRAM when syscfg0 does not have a valid value for the memory type
MIPS: Prevent "restoration" of MSA context in non-MSA kernels
MIPS: cevt-r4k: Dynamically calculate min_delta_ns
MIPS: malta-time: Take seconds into account
MIPS: malta-time: Start GIC count before syncing to RTC
MIPS: Force CPUs to lose FP context during mode switches
...
Move retrieval of compat syscall numbers into inline function defined in
asm-generic header so that arches may override it.
[ralf@linux-mips.org: Resolve merge conflict.]
Suggested-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12978/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Seccomp wants to know the syscall bitness, not the caller task bitness,
when it selects the syscall whitelist.
As far as I know, this makes no difference on any architecture, so it's
not a security problem. (It generates identical code everywhere except
sparc, and, on sparc, the syscall numbering is the same for both ABIs.)
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Before this patch, a process with some permissive seccomp filter
that was applied by root without NO_NEW_PRIVS was able to add
more filters to itself without setting NO_NEW_PRIVS by setting
the new filter from a throwaway thread with NO_NEW_PRIVS.
Signed-off-by: Jann Horn <jann@thejh.net>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
This patch adds support for dumping a process' (classic BPF) seccomp
filters via ptrace.
PTRACE_SECCOMP_GET_FILTER allows the tracer to dump the user's classic BPF
seccomp filters. addr should be an integer which represents the ith seccomp
filter (0 is the most recently installed filter). data should be a struct
sock_filter * with enough room for the ith filter, or NULL, in which case
the filter is not saved. The return value for this command is the number of
BPF instructions the program represents, or negative in the case of errors.
Command specific errors are ENOENT: which indicates that there is no ith
filter in this seccomp tree, and EMEDIUMTYPE, which indicates that the ith
filter was not installed as a classic BPF filter.
A caveat with this approach is that there is no way to get explicitly at
the heirarchy of seccomp filters, and users need to memcmp() filters to
decide which are inherited. This means that a task which installs two of
the same filter can potentially confuse users of this interface.
v2: * make save_orig const
* check that the orig_prog exists (not necessary right now, but when
grows eBPF support it will be)
* s/n/filter_off and make it an unsigned long to match ptrace
* count "down" the tree instead of "up" when passing a filter offset
v3: * don't take the current task's lock for inspecting its seccomp mode
* use a 0x42** constant for the ptrace command value
v4: * don't copy to userspace while holding spinlocks
v5: * add another condition to WARN_ON
v6: * rebase on net-next
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
CC: Will Drewry <wad@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Serge E. Hallyn <serge.hallyn@ubuntu.com>
CC: Alexei Starovoitov <ast@kernel.org>
CC: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current ongoing effort to dump existing cBPF seccomp filters back
to user space requires to hold the pre-transformed instructions like
we do in case of socket filters from sk_attach_filter() side, so they
can be reloaded in original form at a later point in time by utilities
such as criu.
To prepare for this, simply extend the bpf_prog_create_from_user()
API to hold a flag that tells whether we should store the original
or not. Also, fanout filters could make use of that in future for
things like diag. While fanout filters already use bpf_prog_destroy(),
move seccomp over to them as well to handle original programs when
present.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Tested-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For clarity, if CONFIG_SECCOMP isn't defined, seccomp_mode() is returning
"disabled". This makes that more clear, along with another 0-use, and
results in no operational change.
Signed-off-by: Kees Cook <keescook@chromium.org>
This patch is the first step in enabling checkpoint/restore of processes
with seccomp enabled.
One of the things CRIU does while dumping tasks is inject code into them
via ptrace to collect information that is only available to the process
itself. However, if we are in a seccomp mode where these processes are
prohibited from making these syscalls, then what CRIU does kills the task.
This patch adds a new ptrace option, PTRACE_O_SUSPEND_SECCOMP, that enables
a task from the init user namespace which has CAP_SYS_ADMIN and no seccomp
filters to disable (and re-enable) seccomp filters for another task so that
they can be successfully dumped (and restored). We restrict the set of
processes that can disable seccomp through ptrace because although today
ptrace can be used to bypass seccomp, there is some discussion of closing
this loophole in the future and we would like this patch to not depend on
that behavior and be future proofed for when it is removed.
Note that seccomp can be suspended before any filters are actually
installed; this behavior is useful on criu restore, so that we can suspend
seccomp, restore the filters, unmap our restore code from the restored
process' address space, and then resume the task by detaching and have the
filters resumed as well.
v2 changes:
* require that the tracer have no seccomp filters installed
* drop TIF_NOTSC manipulation from the patch
* change from ptrace command to a ptrace option and use this ptrace option
as the flag to check. This means that as soon as the tracer
detaches/dies, seccomp is re-enabled and as a corrollary that one can not
disable seccomp across PTRACE_ATTACHs.
v3 changes:
* get rid of various #ifdefs everywhere
* report more sensible errors when PTRACE_O_SUSPEND_SECCOMP is incorrectly
used
v4 changes:
* get rid of may_suspend_seccomp() in favor of a capable() check in ptrace
directly
v5 changes:
* check that seccomp is not enabled (or suspended) on the tracer
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
CC: Will Drewry <wad@chromium.org>
CC: Roland McGrath <roland@hack.frob.com>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
[kees: access seccomp.mode through seccomp_mode() instead]
Signed-off-by: Kees Cook <keescook@chromium.org>
Recently lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the change.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Seccomp has always been a special candidate when it comes to preparation
of its filters in seccomp_prepare_filter(). Due to the extra checks and
filter rewrite it partially duplicates code and has BPF internals exposed.
This patch adds a generic API inside the BPF code code that seccomp can use
and thus keep it's filter preparation code minimal and better maintainable.
The other side-effect is that now classic JITs can add seccomp support as
well by only providing a BPF_LDX | BPF_W | BPF_ABS translation.
Tested with seccomp and BPF test suites.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nicolas Schichan <nschichan@freebox.fr>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove the calls to bpf_check_classic(), bpf_convert_filter() and
bpf_migrate_runtime() and let bpf_prepare_filter() take care of that
instead.
seccomp_check_filter() is passed to bpf_prepare_filter() so that it
gets called from there, after bpf_check_classic().
We can now remove exposure of two internal classic BPF functions
previously used by seccomp. The export of bpf_check_classic() symbol,
previously known as sk_chk_filter(), was there since pre git times,
and no in-tree module was using it, therefore remove it.
Joint work with Daniel Borkmann.
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
