Dave Hansen 74e19ef0ff uaccess: Add speculation barrier to copy_from_user() ... The results of "access_ok()" can be mis-speculated. The result is that you can end speculatively: if (access_ok(from, size)) // Right here even for bad from/size combinations. On first glance, it would be ideal to just add a speculation barrier to "access_ok()" so that its results can never be mis-speculated. But there are lots of system calls just doing access_ok() via "copy_to_user()" and friends (example: fstat() and friends). Those are generally not problematic because they do not _consume_ data from userspace other than the pointer. They are also very quick and common system calls that should not be needlessly slowed down. "copy_from_user()" on the other hand uses a user-controller pointer and is frequently followed up with code that might affect caches. Take something like this: if (!copy_from_user(&kernelvar, uptr, size)) do_something_with(kernelvar); If userspace passes in an evil 'uptr' that *actually* points to a kernel addresses, and then do_something_with() has cache (or other) side-effects, it could allow userspace to infer kernel data values. Add a barrier to the common copy_from_user() code to prevent mis-speculated values which happen after the copy. Also add a stub for architectures that do not define barrier_nospec(). This makes the macro usable in generic code. Since the barrier is now usable in generic code, the x86 #ifdef in the BPF code can also go away. Reported-by: Jordy Zomer <jordyzomer@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Borkmann <daniel@iogearbox.net> # BPF bits Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2023-02-21 14:45:22 -08:00
..
bpf	uaccess: Add speculation barrier to copy_from_user()	2023-02-21 14:45:22 -08:00
cgroup	cgroup changes for v6.3-rc1	2023-02-21 10:36:29 -08:00
configs	mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATED	2022-12-01 00:09:20 +01:00
debug	kdb: use srcu console list iterator	2022-12-02 11:25:00 +01:00
dma	dma-mapping: reject GFP_COMP for noncoherent allocations	2022-12-21 08:45:38 +01:00
entry	entry: kmsan: introduce kmsan_unpoison_entry_regs()	2022-10-03 14:03:25 -07:00
events	The latest perf updates in this cycle are:	2023-02-20 17:29:55 -08:00
futex	- Prevent the leaking of a debug timer in futex_waitv()	2023-01-01 11:15:05 -08:00
gcov	gcov: add support for checksum field	2022-12-21 14:31:52 -08:00
irq	Updates for the interrupt subsystem:	2023-02-21 10:03:48 -08:00
kcsan	kcsan: test: don't put the expect array on the stack	2023-01-02 08:59:33 -08:00
livepatch	modules changes for v6.2-rc1	2022-12-13 14:05:39 -08:00
locking	RCU pull request for v6.3	2023-02-21 10:45:51 -08:00
module	module: Don't wait for GOING modules	2023-01-24 12:52:52 -08:00
power	Merge branches 'powercap', 'pm-domains', 'pm-em' and 'pm-opp'	2023-02-15 20:06:26 +01:00
printk	Linux 6.2-rc6	2023-01-31 15:01:20 +01:00
rcu	Merge branch 'stall.2023.01.09a' into HEAD	2023-02-02 16:40:07 -08:00
sched	RCU pull request for v6.3	2023-02-21 10:45:51 -08:00
time	Updates for timekeeping, timers and clockevent/source drivers:	2023-02-21 09:45:13 -08:00
trace	Scheduler updates in this cycle are:	2023-02-20 17:41:08 -08:00
.gitignore
acct.c	acct: fix potential integer overflow in encode_comp_t()	2022-11-30 16:13:18 -08:00
async.c
audit.c	audit: use time_after to compare time	2022-08-29 19:47:03 -04:00
audit.h	audit: remove selinux_audit_rule_update() declaration	2022-09-07 11:30:15 -04:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-08-22 18:50:06 -04:00
audit_tree.c
audit_watch.c	audit_init_parent(): constify path	2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c	\n	2023-02-20 12:38:27 -08:00
backtracetest.c
bounds.c	mm: multi-gen LRU: minimal implementation	2022-09-26 19:46:09 -07:00
capability.c	fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap	2023-01-19 09:24:29 +01:00
cfi.c	cfi: Switch to -fsanitize=kcfi	2022-09-26 10:13:13 -07:00
compat.c
configs.c
context_tracking.c	context_tracking: Fix noinstr vs KASAN	2023-01-13 11:48:18 +01:00
cpu.c	cpu/hotplug: Do not bail-out in DYING/STARTING sections	2022-12-02 12:43:02 +01:00
cpu_pm.c	cpuidle, cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}()	2023-01-13 11:48:15 +01:00
crash_core.c	vmcoreinfo: warn if we exceed vmcoreinfo data size	2022-11-30 16:13:17 -08:00
crash_dump.c
cred.c	cred: Do not default to init_cred in prepare_kernel_cred()	2022-11-01 10:04:52 -07:00
delayacct.c	delayacct: support re-entrance detection of thrashing accounting	2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c	exit: Detect and fix irq disabled state in oops	2023-01-21 00:06:10 +01:00
extable.c
fail_function.c	fail_function: fix wrong use of fei_attr_remove()	2022-09-11 21:55:11 -07:00
fork.c	Scheduler updates in this cycle are:	2023-02-20 17:41:08 -08:00
freezer.c	freezer,sched: Rewrite core freezer logic	2022-09-07 21:53:50 +02:00
gen_kheaders.sh	kheaders: explicitly validate existence of cpio command	2023-01-18 16:34:04 +09:00
groups.c
hung_task.c	sched: Fix more TASK_state comparisons	2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c
jump_label.c	jump_label: Prevent key->enabled int overflow	2022-12-01 15:53:05 -08:00
kallsyms.c	kallsyms: Add self-test facility	2022-11-15 00:42:02 -08:00
kallsyms_internal.h	kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[]	2022-11-12 18:47:36 -08:00
kallsyms_selftest.c	kallsyms: Fix scheduling with interrupts disabled in self-test	2023-01-13 15:09:08 -08:00
kallsyms_selftest.h	kallsyms: Add self-test facility	2022-11-15 00:42:02 -08:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: kmsan: unpoison area->list in kcov_remote_area_put()	2022-10-03 14:03:23 -07:00
kexec.c	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kexec_core.c	kexec: remove the unneeded result variable	2022-11-18 13:55:07 -08:00
kexec_elf.c
kexec_file.c	kexec: replace crash_mem_range with range	2022-11-18 13:55:07 -08:00
kexec_internal.h	panic, kexec: make __crash_kexec() NMI safe	2022-09-11 21:55:06 -07:00
kheaders.c
kmod.c
kprobes.c	kprobes: kretprobe events missing on 2-core KVM guest	2022-12-15 08:48:40 +09:00
ksysfs.c	kernel/ksysfs.c: export kernel cpu byteorder	2022-11-10 19:07:31 +01:00
kthread.c	signal: break out of wait loops on kthread_stop()	2022-10-09 16:01:59 -07:00
latencytop.c	latencytop: use the last element of latency_record of system	2022-09-11 21:55:12 -07:00
Makefile	kernel hardening fixes for v6.2-rc1	2022-12-23 12:00:24 -08:00
module_signature.c
notifier.c	kernel/notifier: Remove CONFIG_SRCU	2023-02-02 16:26:06 -08:00
nsproxy.c	fs/exec: switch timens when a task gets a new mm	2022-10-25 15:15:52 -07:00
padata.c	Kbuild updates for v6.2	2022-12-19 12:33:32 -06:00
panic.c	cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG	2023-01-31 15:01:45 +01:00
params.c	Driver Core changes for 6.2-rc1	2022-12-16 03:54:54 -08:00
pid.c
pid_namespace.c	rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()	2023-01-03 17:52:16 -08:00
profile.c	kernel/profile.c: simplify duplicated code in profile_setup()	2022-09-11 21:55:12 -07:00
ptrace.c	rseq: Introduce extensible rseq ABI	2022-12-27 12:52:10 +01:00
range.c
reboot.c	kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode	2022-10-04 15:59:36 +02:00
regset.c
relay.c	relay: fix type mismatch when allocating memory in relay_create_buf()	2022-12-11 19:30:19 -08:00
resource.c	Driver Core changes for 6.2-rc1	2022-12-16 03:54:54 -08:00
resource_kunit.c
rseq.c	rseq: Extend struct rseq with per-memory-map concurrency ID	2022-12-27 12:52:12 +01:00
scftorture.c
scs.c	scs: add support for dynamic shadow call stacks	2022-11-09 18:06:35 +00:00
seccomp.c	seccomp: fix kernel-doc function name warning	2023-01-13 17:01:06 -08:00
signal.c	sched: Introduce per-memory-map concurrency ID	2022-12-27 12:52:11 +01:00
smp.c	bitmap patches for v6.1-rc1	2022-10-10 12:49:34 -07:00
smpboot.c	smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death	2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c
stackleak.c
stacktrace.c
static_call.c
static_call_inline.c	static_call: Add call depth tracking support	2022-10-17 16:41:16 +02:00
stop_machine.c
sys.c	prlimit: do_prlimit needs to have a speculation check	2023-01-21 16:14:17 +01:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-08-20 15:17:45 -07:00
sysctl-test.c	kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred}	2022-09-08 16:56:45 -07:00
sysctl.c	MM patches for 6.2-rc1.	2022-12-13 19:29:45 -08:00
task_work.c	task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run	2022-09-11 21:55:10 -07:00
taskstats.c	genetlink: start to validate reserved header bytes	2022-08-29 12:47:15 +01:00
torture.c	torture: Fix hang during kthread shutdown phase	2023-01-05 12:10:35 -08:00
tracepoint.c	tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming()	2022-09-26 13:01:18 -04:00
tsacct.c
ucount.c
uid16.c
uid16.h
umh.c	freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL	2023-02-13 16:36:14 +01:00
up.c
user-return-notifier.c
user.c	kernel/user: Allow user_struct::locked_vm to be usable for iommufd	2022-11-30 20:16:49 -04:00
user_namespace.c	ucounts: Split rlimit and ucount values and max values	2022-10-09 16:24:05 -07:00
usermode_driver.c
utsname.c
utsname_sysctl.c	kernel/utsname_sysctl.c: Fix hostname polling	2022-10-23 12:01:01 -07:00
watch_queue.c	This was a moderately busy cycle for documentation, but nothing all that	2022-08-02 19:24:24 -07:00
watchdog.c	powerpc updates for 6.0	2022-08-06 16:38:17 -07:00
watchdog_hld.c
workqueue.c	workqueue: Fold rebind_worker() within rebind_workers()	2023-01-13 07:50:40 -10:00
workqueue_internal.h