003e2d74c5
commit 2baae3545327632167c0180e9ca1d467416f1919 upstream.
synchronize_rcu() is fine when the rcu callbacks only need
to free memory (kfree_rcu() or direct kfree() call rcu call backs)
__dev_map_entry_free() is a bit more complex, so we need to make
sure that call queued __dev_map_entry_free() callbacks have completed.
sysbot report:
BUG: KASAN: use-after-free in dev_map_flush_old kernel/bpf/devmap.c:365
[inline]
BUG: KASAN: use-after-free in __dev_map_entry_free+0x2a8/0x300
kernel/bpf/devmap.c:379
Read of size 8 at addr ffff8801b8da38c8 by task ksoftirqd/1/18
CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.17.0+ #39
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
dev_map_flush_old kernel/bpf/devmap.c:365 [inline]
__dev_map_entry_free+0x2a8/0x300 kernel/bpf/devmap.c:379
__rcu_reclaim kernel/rcu/rcu.h:178 [inline]
rcu_do_batch kernel/rcu/tree.c:2558 [inline]
invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline]
__rcu_process_callbacks kernel/rcu/tree.c:2785 [inline]
rcu_process_callbacks+0xe9d/0x1760 kernel/rcu/tree.c:2802
__do_softirq+0x2e0/0xaf5 kernel/softirq.c:284
run_ksoftirqd+0x86/0x100 kernel/softirq.c:645
smpboot_thread_fn+0x417/0x870 kernel/smpboot.c:164
kthread+0x345/0x410 kernel/kthread.c:240
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Allocated by task 6675:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
kmalloc include/linux/slab.h:513 [inline]
kzalloc include/linux/slab.h:706 [inline]
dev_map_alloc+0x208/0x7f0 kernel/bpf/devmap.c:102
find_and_alloc_map kernel/bpf/syscall.c:129 [inline]
map_create+0x393/0x1010 kernel/bpf/syscall.c:453
__do_sys_bpf kernel/bpf/syscall.c:2351 [inline]
__se_sys_bpf kernel/bpf/syscall.c:2328 [inline]
__x64_sys_bpf+0x303/0x510 kernel/bpf/syscall.c:2328
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 26:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kfree+0xd9/0x260 mm/slab.c:3813
dev_map_free+0x4fa/0x670 kernel/bpf/devmap.c:191
bpf_map_free_deferred+0xba/0xf0 kernel/bpf/syscall.c:262
process_one_work+0xc64/0x1b70 kernel/workqueue.c:2153
worker_thread+0x181/0x13a0 kernel/workqueue.c:2296
kthread+0x345/0x410 kernel/kthread.c:240
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
The buggy address belongs to the object at ffff8801b8da37c0
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 264 bytes inside of
512-byte region [ffff8801b8da37c0, ffff8801b8da39c0)
The buggy address belongs to the page:
page:ffffea0006e368c0 count:1 mapcount:0 mapping:ffff8801da800940
index:0xffff8801b8da3540
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0007217b88 ffffea0006e30cc8 ffff8801da800940
raw: ffff8801b8da3540 ffff8801b8da3040 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801b8da3780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff8801b8da3800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8801b8da3880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8801b8da3900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b8da3980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
Fixes:
|
||
---|---|---|
.. | ||
bpf | ||
cgroup | ||
configs | ||
debug | ||
dma | ||
events | ||
gcov | ||
irq | ||
livepatch | ||
locking | ||
power | ||
printk | ||
rcu | ||
sched | ||
time | ||
trace | ||
.gitignore | ||
acct.c | ||
async.c | ||
audit.c | ||
audit.h | ||
audit_fsnotify.c | ||
audit_tree.c | ||
audit_watch.c | ||
auditfilter.c | ||
auditsc.c | ||
backtracetest.c | ||
bounds.c | ||
capability.c | ||
compat.c | ||
configs.c | ||
context_tracking.c | ||
cpu.c | ||
cpu_pm.c | ||
crash_core.c | ||
crash_dump.c | ||
cred.c | ||
delayacct.c | ||
dma.c | ||
elfcore.c | ||
exec_domain.c | ||
exit.c | ||
extable.c | ||
fail_function.c | ||
fork.c | ||
freezer.c | ||
futex.c | ||
futex_compat.c | ||
groups.c | ||
hung_task.c | ||
iomem.c | ||
irq_work.c | ||
jump_label.c | ||
kallsyms.c | ||
kcmp.c | ||
Kconfig.freezer | ||
Kconfig.hz | ||
Kconfig.locks | ||
Kconfig.preempt | ||
kcov.c | ||
kexec.c | ||
kexec_core.c | ||
kexec_file.c | ||
kexec_internal.h | ||
kmod.c | ||
kprobes.c | ||
ksysfs.c | ||
kthread.c | ||
latencytop.c | ||
Makefile | ||
memremap.c | ||
module-internal.h | ||
module.c | ||
module_signing.c | ||
notifier.c | ||
nsproxy.c | ||
padata.c | ||
panic.c | ||
params.c | ||
pid.c | ||
pid_namespace.c | ||
profile.c | ||
ptrace.c | ||
range.c | ||
reboot.c | ||
relay.c | ||
resource.c | ||
rseq.c | ||
seccomp.c | ||
signal.c | ||
smp.c | ||
smpboot.c | ||
smpboot.h | ||
softirq.c | ||
stacktrace.c | ||
stop_machine.c | ||
sys.c | ||
sys_ni.c | ||
sysctl.c | ||
sysctl_binary.c | ||
task_work.c | ||
taskstats.c | ||
test_kprobes.c | ||
torture.c | ||
tracepoint.c | ||
tsacct.c | ||
ucount.c | ||
uid16.c | ||
uid16.h | ||
umh.c | ||
up.c | ||
user-return-notifier.c | ||
user.c | ||
user_namespace.c | ||
utsname.c | ||
utsname_sysctl.c | ||
watchdog.c | ||
watchdog_hld.c | ||
workqueue.c | ||
workqueue_internal.h |