linux-stable/kernel
Daniel Axtens 7821131c16 kernel/relay.c: handle alloc_percpu returning NULL in relay_open
commit 54e200ab40 upstream.

alloc_percpu() may return NULL, which means chan->buf may be set to NULL.
In that case, when we do *per_cpu_ptr(chan->buf, ...), we dereference an
invalid pointer:

  BUG: Unable to handle kernel data access at 0x7dae0000
  Faulting instruction address: 0xc0000000003f3fec
  ...
  NIP relay_open+0x29c/0x600
  LR relay_open+0x270/0x600
  Call Trace:
     relay_open+0x264/0x600 (unreliable)
     __blk_trace_setup+0x254/0x600
     blk_trace_setup+0x68/0xa0
     sg_ioctl+0x7bc/0x2e80
     do_vfs_ioctl+0x13c/0x1300
     ksys_ioctl+0x94/0x130
     sys_ioctl+0x48/0xb0
     system_call+0x5c/0x68

Check if alloc_percpu returns NULL.

This was found by syzkaller both on x86 and powerpc, and the reproducer
it found on powerpc is capable of hitting the issue as an unprivileged
user.

Fixes: 017c59c042 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: syzbot+1e925b4b836afe85a1c6@syzkaller-ppc64.appspotmail.com
Reported-by: syzbot+587b2421926808309d21@syzkaller-ppc64.appspotmail.com
Reported-by: syzbot+58320b7171734bf79d26@syzkaller.appspotmail.com
Reported-by: syzbot+d6074fb08bdb2e010520@syzkaller.appspotmail.com
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Akash Goel <akash.goel@intel.com>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Salvatore Bonaccorso <carnil@debian.org>
Cc: <stable@vger.kernel.org>	[4.10+]
Link: http://lkml.kernel.org/r/20191219121256.26480-1-dja@axtens.net
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-11 09:22:58 +02:00
..
bpf bpf: Explicitly memset some bpf info structures declared on the stack 2020-04-02 16:34:37 +02:00
cgroup cgroup1: don't call release_agent when it is "" 2020-04-02 16:34:27 +02:00
configs ANDROID: binder: add hwbinder,vndbinder to BINDER_DEVICES. 2017-08-22 18:43:23 -07:00
debug kdb: do a sanity check on the cpu in kdb_per_cpu() 2020-01-27 14:46:34 +01:00
events perf/core: fix parent pid/tid in task exit events 2020-05-02 17:24:42 +02:00
gcov kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-05-02 17:24:14 +02:00
irq genirq/generic_pending: Do not lose pending affinity update 2020-06-03 08:18:12 +02:00
livepatch livepatch: Nullify obj->mod in klp_module_coming()'s error path 2019-10-07 18:55:09 +02:00
locking locktorture: Print ratio of acquisitions, not failures 2020-04-24 08:01:23 +02:00
power PM: hibernate: Freeze kernel threads in software_resume() 2020-05-05 19:15:50 +02:00
printk printk: fix integer overflow in setup_log_buf() 2019-12-01 09:13:17 +01:00
rcu rcuperf: Fix cleanup path for invalid perf_type strings 2019-05-31 06:47:33 -07:00
sched sched: Avoid scale real weight down to zero 2020-04-24 08:00:26 +02:00
time clocksource: Prevent double add_timer_on() for watchdog_timer 2020-02-14 16:32:20 -05:00
trace Stop the ad-hoc games with -Wno-maybe-initialized 2020-05-20 08:17:10 +02:00
.gitignore
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-10 09:31:17 +01:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-16 20:23:05 +01:00
audit.c audit: check the length of userspace generated audit records 2020-05-02 17:24:31 +02:00
audit.h ipc: mqueue: Replace timespec with timespec64 2017-09-03 20:21:24 -04:00
audit_fsnotify.c
audit_tree.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
audit_watch.c audit_get_nd(): don't unlock parent too early 2019-12-17 20:37:27 +01:00
auditfilter.c audit: fix error handling in audit_data_to_entry() 2020-03-11 18:02:48 +01:00
auditsc.c audit: print empty EXECVE args 2019-12-01 09:14:03 +01:00
backtracetest.c
bounds.c kbuild: fix kernel/bounds.c 'W=1' warning 2018-11-13 11:15:08 -08:00
capability.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat.c compat: fix 4-byte infoleak via uninitialized struct field 2018-05-16 10:10:26 +02:00
configs.c
context_tracking.c
cpu.c x86/speculation: Remove redundant arch_smt_update() invocation 2020-04-24 08:00:41 +02:00
cpu_pm.c PM / CPU: replace raw_notifier with atomic_notifier 2017-07-31 13:09:49 +02:00
crash_core.c kdump: write correct address of mem_section into vmcoreinfo 2018-01-17 09:45:27 +01:00
crash_dump.c
cred.c memcg: account security cred as well to kmemcg 2020-01-09 10:17:54 +01:00
delayacct.c delayacct: Use raw_spinlocks 2018-08-03 07:50:38 +02:00
dma.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
elfcore.c kernel/elfcore.c: include proper prototypes 2019-10-11 18:18:42 +02:00
exec_domain.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exit.c exit: panic before exit_mm() on global init exit 2020-01-09 10:17:56 +01:00
extable.c extable: Enable RCU if it is not watching in kernel_text_address() 2017-09-23 16:50:20 -04:00
fork.c futex: Split futex_mm_release() for exit/exec 2019-12-05 15:38:26 +01:00
freezer.c
futex.c futex: Unbreak futex hashing 2020-04-02 16:34:21 +02:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-20 10:10:18 +01:00
hung_task.c kernel: hung_task.c: disable on suspend 2019-04-20 09:15:05 +02:00
irq_work.c
jump_label.c sched/core: Fix cpu.max vs. cpuhotplug deadlock 2018-12-05 19:41:17 +01:00
kallsyms.c kallsyms: Don't let kallsyms_lookup_size_offset() fail on retrieving the first symbol 2019-09-21 07:15:38 +02:00
kcmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: ensure irq code sees a valid area 2018-08-03 07:50:22 +02:00
kexec.c kdump: protect vmcoreinfo data under the crash memory 2017-07-12 16:26:00 -07:00
kexec_core.c kexec: Allocate decrypted control pages for kdump if SME is enabled 2019-11-24 08:23:15 +01:00
kexec_file.c kexec_file: adjust declaration of kexec_purgatory 2017-07-12 16:26:02 -07:00
kexec_internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-24 08:00:44 +02:00
kprobes.c kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic 2020-03-11 18:02:57 +01:00
ksysfs.c kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
kthread.c kthread, tracing: Don't expose half-written comm when creating kthreads 2018-08-03 07:50:21 +02:00
latencytop.c
Makefile y2038: futex: Move compat implementation into futex.c 2019-12-05 15:38:22 +01:00
memremap.c mm, devm_memremap_pages: kill mapping "System RAM" support 2019-01-13 10:01:02 +01:00
module-internal.h
module.c kernel/module: Fix memleak in module_add_modinfo_attrs() 2020-02-14 16:32:06 -05:00
module_signing.c
notifier.c x86/mm: split vmalloc_sync_all() 2020-04-02 16:34:20 +02:00
nsproxy.c
padata.c padata: purge get_cpu and reorder_via_wq from padata_do_serial 2020-05-27 16:43:05 +02:00
panic.c panic: ensure preemption is disabled during panic() 2019-10-17 13:43:19 -07:00
params.c kernel/params.c: improve STANDARD_PARAM_DEF readability 2017-10-03 17:54:26 -07:00
pid.c pids: make task_tgid_nr_ns() safe 2017-08-21 12:47:31 -07:00
pid_namespace.c signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig 2019-07-31 07:28:21 +02:00
profile.c
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-23 08:20:32 +01:00
range.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reboot.c
relay.c kernel/relay.c: handle alloc_percpu returning NULL in relay_open 2020-06-11 09:22:58 +02:00
resource.c resource: fix integer overflow at reallocation 2018-04-24 09:36:22 +02:00
seccomp.c seccomp: Move speculation migitation control to arch code 2018-05-22 18:54:04 +02:00
signal.c signal: Extend exec_id to 64bits 2020-04-24 08:00:38 +02:00
smp.c cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM 2019-02-12 19:46:13 +01:00
smpboot.c watchdog/core, powerpc: Lock cpus across reconfiguration 2017-10-04 10:53:54 +02:00
smpboot.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
softirq.c Mark HI and TASKLET softirq synchronous 2018-08-15 18:12:47 +02:00
stacktrace.c
stop_machine.c stop_machine: Atomically queue and wake stopper threads 2018-09-05 09:26:36 +02:00
sys.c kernel/sys.c: prctl: fix false positive in validate_prctl_map() 2019-06-15 11:54:52 +02:00
sys_ni.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysctl.c kernel: sysctl: make drop_caches write-only 2020-01-04 13:59:57 +01:00
sysctl_binary.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
task_work.c locking/barriers: Convert users of lockless_dereference() to READ_ONCE() 2017-12-25 14:26:21 +01:00
taskstats.c taskstats: fix data-race 2020-01-09 10:17:53 +01:00
test_kprobes.c
torture.c torture: Fix typo suppressing CPU-hotplug statistics 2017-07-25 13:04:45 -07:00
tracepoint.c tracepoint: Do not warn on ENOMEM 2018-05-09 09:51:50 +02:00
tsacct.c
ucount.c
uid16.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-20 10:10:18 +01:00
umh.c coredump: fix crash when umh is disabled 2020-05-20 08:16:58 +02:00
up.c smp: Avoid using two cache lines for struct call_single_data 2017-08-29 15:14:38 +02:00
user-return-notifier.c
user.c
user_namespace.c userns: move user access out of the mutex 2018-09-09 19:56:00 +02:00
utsname.c
utsname_sysctl.c sys: don't hold uts_sem while accessing userspace memory 2018-09-09 19:56:00 +02:00
watchdog.c watchdog/softlockup: Enforce that timestamp is valid on boot 2020-02-28 16:36:05 +01:00
watchdog_hld.c watchdog: Mark watchdog touch functions as notrace 2018-09-05 09:26:42 +02:00
workqueue.c workqueue: don't use wq_select_unbound_cpu() for bound works 2020-03-20 10:54:16 +01:00
workqueue_internal.h Merge branch 'for-4.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2017-11-06 12:26:49 -08:00