linux/kernel
Halil Pasic aa6f8dcbab swiotlb: rework "fix info leak with DMA_FROM_DEVICE"
Unfortunately, we ended up merging an old version of the patch "fix info
leak with DMA_FROM_DEVICE" instead of merging the latest one. Christoph
(the swiotlb maintainer), he asked me to create an incremental fix
(after I have pointed this out the mix up, and asked him for guidance).
So here we go.

The main differences between what we got and what was agreed are:
* swiotlb_sync_single_for_device is also required to do an extra bounce
* We decided not to introduce DMA_ATTR_OVERWRITE until we have exploiters
* The implantation of DMA_ATTR_OVERWRITE is flawed: DMA_ATTR_OVERWRITE
  must take precedence over DMA_ATTR_SKIP_CPU_SYNC

Thus this patch removes DMA_ATTR_OVERWRITE, and makes
swiotlb_sync_single_for_device() bounce unconditionally (that is, also
when dir == DMA_TO_DEVICE) in order do avoid synchronising back stale
data from the swiotlb buffer.

Let me note, that if the size used with dma_sync_* API is less than the
size used with dma_[un]map_*, under certain circumstances we may still
end up with swiotlb not being transparent. In that sense, this is no
perfect fix either.

To get this bullet proof, we would have to bounce the entire
mapping/bounce buffer. For that we would have to figure out the starting
address, and the size of the mapping in
swiotlb_sync_single_for_device(). While this does seem possible, there
seems to be no firm consensus on how things are supposed to work.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Fixes: ddbd89deb7 ("swiotlb: fix info leak with DMA_FROM_DEVICE")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-07 11:26:02 -08:00
..
bpf bpf: Add schedule points in batch ops 2022-02-17 10:48:26 -08:00
cgroup Merge branch 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2022-02-22 16:14:35 -08:00
configs configs/debug: set CONFIG_DEBUG_INFO=y properly 2022-03-05 11:08:33 -08:00
debug kdb: Adopt scheduler's task classification 2021-11-03 17:21:37 +00:00
dma swiotlb: rework "fix info leak with DMA_FROM_DEVICE" 2022-03-07 11:26:02 -08:00
entry entry: Snapshot thread flags 2021-12-01 00:06:43 +01:00
events perf: Fix list corruption in perf_cgroup_switch() 2022-02-06 22:37:27 +01:00
futex Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
gcov gcov: Remove compiler version check 2021-12-02 17:25:21 +09:00
irq proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
kcsan KCSAN updates for v5.17 2022-01-11 09:51:26 -08:00
livepatch Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
locking lockdep: Correct lock_classes index mapping 2022-02-11 23:30:02 +01:00
power PM: s2idle: ACPI: Fix wakeup interrupts handling 2022-02-07 21:02:31 +01:00
printk printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin() 2022-02-03 11:27:38 -08:00
rcu rcu-tasks: Fix computation of CPU-to-list shift counts 2022-01-26 13:04:05 -08:00
sched sched: Fix yet more sched_fork() races 2022-02-19 11:11:05 +01:00
time bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
trace Two tracing fixes: 2022-03-06 11:47:59 -08:00
.gitignore
acct.c kernel: remove spurious blkdev.h includes 2021-10-18 06:17:01 -06:00
async.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
audit_fsnotify.c fsnotify: clarify contract for create event hooks 2021-10-27 12:32:34 +02:00
audit_tree.c audit: use struct_size() helper in kmalloc() 2021-12-14 17:39:42 -05:00
audit_watch.c \n 2021-11-06 16:43:20 -07:00
audit.c audit: improve audit queue handling when "audit=1" on cmdline 2022-01-25 13:22:51 -05:00
audit.h audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
auditfilter.c audit/stable-5.17 PR 20220110 2022-01-11 13:08:21 -08:00
auditsc.c audit: don't deref the syscall args when checking the openat2 open_how::flags 2022-02-09 16:04:26 -05:00
backtracetest.c
bounds.c
capability.c
cfi.c cfi: Use rcu_read_{un}lock_sched_notrace 2021-08-11 13:11:12 -07:00
compat.c arch: remove compat_alloc_user_space 2021-09-08 15:32:35 -07:00
configs.c
context_tracking.c
cpu_pm.c PM: cpu: Make notifier chain use a raw_spinlock_t 2021-08-16 18:55:32 +02:00
cpu.c sched/scs: Reset task stack state in bringup_cpu() 2021-11-24 12:20:27 +01:00
crash_core.c kernel/crash_core: suppress unknown crashkernel parameter warning 2021-12-25 12:20:55 -08:00
crash_dump.c
cred.c ucounts: Base set_cred_ucounts changes on the real user 2022-02-17 09:11:02 -06:00
delayacct.c delayacct: track delays from memory compact 2022-01-20 08:52:55 +02:00
dma.c
exec_domain.c
exit.c exit: Fix the exit_code for wait_task_zombie 2022-01-08 12:43:57 -06:00
extable.c extable: use is_kernel_text() helper 2021-11-09 10:02:51 -08:00
fail_function.c
fork.c mm: refactor vm_area_struct::anon_vma_name usage code 2022-03-05 11:08:32 -08:00
freezer.c sched: Add get_current_state() 2021-06-18 11:43:08 +02:00
gen_kheaders.sh
groups.c
hung_task.c hung_task: move hung_task sysctl interface to hung_task.c 2022-01-22 08:33:34 +02:00
iomem.c
irq_work.c irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT 2021-10-15 11:25:18 +02:00
jump_label.c jump_label: Fix jump_label_text_reserved() vs __init 2021-07-05 10:46:20 +02:00
kallsyms.c Livepatching changes for 5.17 2022-01-16 10:08:13 +02:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/rwlock: Provide RT variant 2021-08-17 17:50:51 +02:00
Kconfig.preempt preempt: Restore preemption model selection configs 2021-11-11 13:09:33 +01:00
kcov.c kcov: replace local_irq_save() with a local_lock_t 2021-11-09 10:02:52 -08:00
kexec_core.c exit: Move oops specific logic from do_exit into make_task_dead 2021-12-13 12:04:45 -06:00
kexec_elf.c
kexec_file.c memblock: add MEMBLOCK_DRIVER_MANAGED to mimic IORESOURCE_SYSRAM_DRIVER_MANAGED 2021-11-06 13:30:42 -07:00
kexec_internal.h
kexec.c kexec: avoid compat_alloc_user_space 2021-09-08 15:32:34 -07:00
kheaders.c
kmod.c
kprobes.c kprobe: move sysctl_kprobes_optimization to kprobes.c 2022-01-22 08:33:36 +02:00
ksysfs.c
kthread.c Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
latencytop.c
Makefile module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module_decompress.c module: fix building with sysfs disabled 2022-02-16 12:51:32 -08:00
module_signature.c
module_signing.c
module-internal.h module: add in-kernel support for decompressing 2022-01-11 18:45:02 -08:00
module.c Revert "module, async: async_synchronize_full() on module init iff async is used" 2022-02-03 11:20:34 -08:00
notifier.c notifier: Return an error when a callback has already been registered 2021-12-29 10:37:33 +01:00
nsproxy.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
padata.c padata: Remove repeated verbose license text 2021-08-27 16:30:18 +08:00
panic.c panic: remove oops_id 2022-01-20 08:52:55 +02:00
params.c kobject: remove kset from struct kset_uevent_ops callbacks 2021-12-28 11:26:18 +01:00
pid_namespace.c memcg: enable accounting for new namesapces and struct nsproxy 2021-09-03 09:58:12 -07:00
pid.c pid: add pidfd_get_task() helper 2021-10-14 13:29:18 +02:00
profile.c exit: Remove profile_handoff_task 2022-01-08 12:43:57 -06:00
ptrace.c ptrace: Remove second setting of PT_SEIZED in ptrace_attach 2022-01-08 12:43:57 -06:00
range.c
reboot.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2021-11-12 11:53:16 -08:00
regset.c
relay.c
resource_kunit.c
resource.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
rseq.c KVM: rseq: Update rseq when processing NOTIFY_RESUME on xfer to KVM guest 2021-09-22 10:24:01 -04:00
scftorture.c scftorture: Always log error message 2021-12-07 16:36:17 -08:00
scs.c scs: Release kasan vmalloc poison in scs_free process 2021-09-30 09:37:27 +01:00
seccomp.c seccomp: Invalidate seccomp mode to catch death failures 2022-02-10 19:09:12 -08:00
signal.c signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE 2022-02-10 19:08:54 -08:00
smp.c sched: Improve wake_up_all_idle_cpus() take #2 2021-10-22 15:32:46 +02:00
smpboot.c smpboot: Replace deprecated CPU-hotplug functions. 2021-08-10 14:57:42 +02:00
smpboot.h
softirq.c timers/nohz: Last resort update jiffies on nohz_full IRQ entry 2021-12-02 15:07:22 +01:00
stackleak.c gcc-plugins/stackleak: Use noinstr in favor of notrace 2022-02-03 17:02:21 -08:00
stacktrace.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2021-11-06 13:30:43 -07:00
static_call.c static_call: Fix static_call_text_reserved() vs __init 2021-07-05 10:46:33 +02:00
stop_machine.c
sys_ni.c mm/mempolicy: wire up syscall set_mempolicy_home_node 2022-01-15 16:30:30 +02:00
sys.c mm: refactor vm_area_struct::anon_vma_name usage code 2022-03-05 11:08:32 -08:00
sysctl-test.c kernel/sysctl-test: Remove some casts which are no-longer required 2021-06-23 16:41:24 -06:00
sysctl.c sysctl: returns -EINVAL when a negative value is passed to proc_doulongvec_minmax 2022-01-22 08:33:37 +02:00
task_work.c
taskstats.c
torture.c locktorture,rcutorture,torture: Always log error message 2021-12-07 16:36:17 -08:00
tracepoint.c tracepoint: Fix kerneldoc comments 2021-08-16 11:39:51 -04:00
tsacct.c taskstats: Cleanup the use of task->exit_code 2022-01-08 12:43:57 -06:00
ucount.c ucounts: Handle wrapping in is_ucounts_overlimit 2022-02-17 09:11:57 -06:00
uid16.c
uid16.h
umh.c
up.c
user_namespace.c ucounts: Fix systemd LimitNPROC with private users regression 2022-02-25 10:40:14 -06:00
user-return-notifier.c
user.c fs/epoll: use a per-cpu counter for user's watches count 2021-09-08 11:50:27 -07:00
usermode_driver.c Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-07-03 11:41:14 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c
watchdog_hld.c
watchdog.c watchdog: move watchdog sysctl interface to watchdog.c 2022-01-22 08:33:34 +02:00
workqueue_internal.h workqueue: Assign a color to barrier work items 2021-08-17 07:49:10 -10:00
workqueue.c Merge branch 'workqueue/for-5.16-fixes' into workqueue/for-5.17 2022-01-10 07:54:04 -10:00