linux_dsm_epyc7002/kernel
Yonghong Song 06ef0ccb5a bpf/cgroup: fix a verification error for a CGROUP_DEVICE type prog
The tools/testing/selftests/bpf test program
test_dev_cgroup fails with the following error
when compiled with llvm 6.0. (I did not try
with earlier versions.)

  libbpf: load bpf program failed: Permission denied
  libbpf: -- BEGIN DUMP LOG ---
  libbpf:
  0: (61) r2 = *(u32 *)(r1 +4)
  1: (b7) r0 = 0
  2: (55) if r2 != 0x1 goto pc+8
   R0=inv0 R1=ctx(id=0,off=0,imm=0) R2=inv1 R10=fp0
  3: (69) r2 = *(u16 *)(r1 +0)
  invalid bpf_context access off=0 size=2
  ...

The culprit is the following statement in dev_cgroup.c:
  short type = ctx->access_type & 0xFFFF;
This code is typical as the ctx->access_type is assigned
as below in kernel/bpf/cgroup.c:
  struct bpf_cgroup_dev_ctx ctx = {
        .access_type = (access << 16) | dev_type,
        .major = major,
        .minor = minor,
  };

The compiler converts it to u16 access while
the verifier cgroup_dev_is_valid_access rejects
any non u32 access.

This patch permits the field access_type to be accessible
with type u16 and u8 as well.

Signed-off-by: Yonghong Song <yhs@fb.com>
Tested-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-19 01:43:29 +01:00
..
bpf bpf/cgroup: fix a verification error for a CGROUP_DEVICE type prog 2017-12-19 01:43:29 +01:00
cgroup Revert "cgroup/cpuset: remove circular dependency deadlock" 2017-12-04 14:55:59 -08:00
configs
debug kdb: Fix handling of kallsyms_symbol_next() return value 2017-12-06 16:12:43 -06:00
events Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2017-12-18 10:51:06 -05:00
gcov
irq genirq/matrix: Fix the precedence fix for real 2017-12-04 20:50:35 +01:00
livepatch
locking locking/lockdep: Remove the cross-release locking checks 2017-12-12 12:38:51 +01:00
power Revert "cpuset: Make cpuset hotplug synchronous" 2017-12-04 14:41:11 -08:00
printk remove task and stack pointer printout from oops dump 2017-12-05 08:23:20 -08:00
rcu
sched sched/rt: Do not pull from current CPU if only one CPU to pull 2017-12-15 16:28:02 +01:00
time
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2017-12-18 10:51:06 -05:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-06 17:45:36 -08:00
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c arch: define weak abort() 2017-12-14 16:00:49 -08:00
extable.c
fork.c
freezer.c
futex_compat.c
futex.c futex: futex_wake_op, fix sign_extend32 sign bits 2017-12-10 12:50:57 -08:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c
irq_work.c
jump_label.c
kallsyms.c kallsyms: take advantage of the new '%px' format 2017-11-29 10:30:13 -08:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: fix comparison callback signature 2017-12-14 16:00:48 -08:00
kexec_core.c
kexec_file.c
kexec_internal.h
kexec.c
kmod.c
kprobes.c add infrastructure for tagging functions as error injectable 2017-12-12 08:56:26 -08:00
ksysfs.c
kthread.c
latencytop.c
Makefile
memremap.c
module_signing.c
module-internal.h
module.c add infrastructure for tagging functions as error injectable 2017-12-12 08:56:26 -08:00
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_binary.c
sysctl.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
umh.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog_hld.c
watchdog.c
workqueue_internal.h
workqueue.c workqueue: remove unneeded kallsyms include 2017-12-11 07:15:43 -08:00