linux/kernel
Steven Rostedt (VMware) 9dc9648942 ring-buffer: Mask out the info bits when returning buffer page length
commit 45d8b80c2a upstream.

Two info bits were added to the "commit" part of the ring buffer data page
when returned to be consumed. This was to inform the user space readers that
events have been missed, and that the count may be stored at the end of the
page.

What wasn't handled, was the splice code that actually called a function to
return the length of the data in order to zero out the rest of the page
before sending it up to user space. These data bits were returned with the
length making the value negative, and that negative value was not checked.
It was compared to PAGE_SIZE, and only used if the size was less than
PAGE_SIZE. Luckily PAGE_SIZE is unsigned long which made the compare an
unsigned compare, meaning the negative size value did not end up causing a
large portion of memory to be randomly zeroed out.

Fixes: 66a8cb95ed ("ring-buffer: Add place holder recording of dropped events")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02 20:33:22 +01:00
..
bpf bpf: don't let ldimm64 leak map addresses on unprivileged 2017-11-21 09:21:17 +01:00
configs kconfig: tinyconfig: provide whole choice blocks to avoid warnings 2016-09-24 10:07:42 +02:00
debug kdb: Fix handling of kallsyms_symbol_next() return value 2017-12-16 10:33:49 +01:00
events bpf: one perf event close won't free bpf program attached by another perf event 2017-10-21 17:09:02 +02:00
gcov gcov: support GCC 7.1 2017-09-02 07:06:51 +02:00
irq genirq: Release resources in __setup_irq() error path 2017-06-26 07:13:10 +02:00
livepatch
locking locking/lockdep: Add nest_lock integrity test 2017-10-21 17:09:03 +02:00
power sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs 2017-10-12 11:27:35 +02:00
printk printk: use rcuidle console tracepoint 2017-02-23 17:43:10 +01:00
rcu rcu: Allow for page faults in NMI handlers 2017-10-18 09:20:41 +02:00
sched sched/core: Idle_task_exit() shouldn't use switch_mm_irqs_off() 2017-12-25 14:22:09 +01:00
time timer/sysclt: Restrict timer migration sysctl values to 0 and 1 2017-10-05 09:41:47 +02:00
trace ring-buffer: Mask out the info bits when returning buffer page length 2018-01-02 20:33:22 +01:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c audit: Fix use after free in audit_remove_watch_rule() 2017-08-24 17:02:35 -07:00
audit.c audit: ensure that 'audit=1' actually enables audit for PID 1 2017-12-16 10:33:56 +01:00
audit.h
auditfilter.c
auditsc.c audit: fix a double fetch in audit_log_single_execve_arg() 2016-08-20 18:09:22 +02:00
backtracetest.c
bounds.c
capability.c exec: Ensure mm->user_ns contains the execed files 2017-01-06 11:16:14 +01:00
cgroup_freezer.c
cgroup_pids.c
cgroup.c cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups 2017-04-21 09:30:04 +02:00
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c stable-fixup: hotplug: fix unused function warning 2017-01-12 11:22:48 +01:00
cpuset.c sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs 2017-10-12 11:27:35 +02:00
crash_dump.c
cred.c cred: Reject inodes with invalid ids in set_create_file_as() 2016-09-15 08:27:49 +02:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c wait/ptrace: assume __WALL if the child is traced 2016-06-07 18:14:35 -07:00
extable.c kernel/extable.c: mark core_kernel_text notrace 2017-07-21 07:44:56 +02:00
fork.c stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms 2017-06-14 13:16:23 +02:00
freezer.c
futex_compat.c
futex.c futex: Add missing error handling to FUTEX_REQUEUE_PI 2017-03-22 12:04:19 +01:00
groups.c
hung_task.c
irq_work.c
jump_label.c jump_label: Invoke jump_label_test() via early_initcall() 2017-12-16 10:33:55 +01:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec_core.c
kexec_file.c kexec: fix double-free when failing to relocate the purgatory 2016-09-24 10:07:36 +02:00
kexec_internal.h
kexec.c
kmod.c
kprobes.c tracing/kprobes: Enforce kprobes teardown after testing 2017-05-25 14:30:17 +02:00
ksysfs.c
kthread.c cgroup, kthread: close race window where new kthreads can be migrated to non-root cgroups 2017-04-21 09:30:04 +02:00
latencytop.c
Makefile
membarrier.c Fix: Disable sys_membarrier when nohz_full is enabled 2017-03-12 06:37:26 +01:00
memremap.c mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} 2017-01-19 20:17:18 +01:00
module_signing.c
module-internal.h
module.c module: Invalidate signatures on force-loaded modules 2016-08-20 18:09:27 +02:00
notifier.c
nsproxy.c
padata.c padata: free correct variable 2017-05-20 14:27:02 +02:00
panic.c kernel/panic.c: add missing \n 2017-07-05 14:37:19 +02:00
params.c
pid_namespace.c pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes 2017-05-25 14:30:11 +02:00
pid.c pids: make task_tgid_nr_ns() safe 2017-08-24 17:02:36 -07:00
profile.c
ptrace.c ptrace: Properly initialize ptracer_cred on fork 2017-06-14 13:16:20 +02:00
range.c
reboot.c
relay.c
resource.c /proc/iomem: only expose physical resource addresses to privileged users 2017-08-06 19:19:42 -07:00
seccomp.c seccomp: fix the usage of get/put_seccomp_filter() in seccomp_get_filter() 2017-10-05 09:41:46 +02:00
signal.c signal: protect SIGNAL_UNKILLABLE from unintentional clearing. 2017-08-11 09:08:59 -07:00
smp.c
smpboot.c
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_binary.c
sysctl.c timer/sysclt: Restrict timer migration sysctl values to 0 and 1 2017-10-05 09:41:47 +02:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c kernel/watchdog: use nmi registers snapshot in hardlockup handler 2017-01-06 11:16:16 +01:00
workqueue_internal.h workqueue: Fix NULL pointer dereference 2017-11-15 17:13:11 +01:00
workqueue.c workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq 2017-12-16 10:33:52 +01:00