Yonghong Song d81ddadabd bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper ... commit b910eaaaa4 upstream. Jiri Olsa reported a bug ([1]) in kernel where cgroup local storage pointer may be NULL in bpf_get_local_storage() helper. There are two issues uncovered by this bug: (1). kprobe or tracepoint prog incorrectly sets cgroup local storage before prog run, (2). due to change from preempt_disable to migrate_disable, preemption is possible and percpu storage might be overwritten by other tasks. This issue (1) is fixed in [2]. This patch tried to address issue (2). The following shows how things can go wrong: task 1: bpf_cgroup_storage_set() for percpu local storage preemption happens task 2: bpf_cgroup_storage_set() for percpu local storage preemption happens task 1: run bpf program task 1 will effectively use the percpu local storage setting by task 2 which will be either NULL or incorrect ones. Instead of just one common local storage per cpu, this patch fixed the issue by permitting 8 local storages per cpu and each local storage is identified by a task_struct pointer. This way, we allow at most 8 nested preemption between bpf_cgroup_storage_set() and bpf_cgroup_storage_unset(). The percpu local storage slot is released (calling bpf_cgroup_storage_unset()) by the same task after bpf program finished running. bpf_test_run() is also fixed to use the new bpf_cgroup_storage_set() interface. The patch is tested on top of [2] with reproducer in [1]. Without this patch, kernel will emit error in 2-3 minutes. With this patch, after one hour, still no error. [1] https://lore.kernel.org/bpf/CAKH8qBuXCfUz=w8L+Fj74OaUpbosO29niYwTki7e3Ag044_aww@mail.gmail.com/T [2] https://lore.kernel.org/bpf/20210309185028.3763817-1-yhs@fb.com Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Link: https://lore.kernel.org/bpf/20210323055146.3334476-1-yhs@fb.com Cc: <stable@vger.kernel.org> # 5.10.x Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-09-03 10:09:21 +02:00
..
bpf	bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper	2021-09-03 10:09:21 +02:00
cgroup	cgroup1: fix leaked context root causing sporadic NULL deref in LTP	2021-07-31 08:16:11 +02:00
configs
debug	kgdb: fix to kill breakpoints on initmem after boot	2021-03-04 11:38:46 +01:00
dma	dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable}	2021-07-28 14:35:38 +02:00
entry	x86/entry: Move nmi entry/exit into common code	2021-03-17 17:06:36 +01:00
events	perf: Fix data race between pin_count increment/decrement	2021-06-16 12:01:45 +02:00
gcov	gcov: re-fix clang-11+ support	2021-04-14 08:41:58 +02:00
irq	genirq/timings: Prevent potential array overflow in __irq_timings_store()	2021-08-18 08:59:15 +02:00
kcsan	kcsan: Fix debugfs initcall return type	2021-05-26 12:06:54 +02:00
livepatch	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
locking	lockdep: Fix wait-type for empty stack	2021-07-14 16:56:10 +02:00
power	PM: EM: postpone creating the debugfs dir till fs_initcall	2021-03-30 14:32:04 +02:00
printk	printk: fix deadlock when kernel panic	2021-03-04 11:38:41 +01:00
rcu	rcu-tasks: Don't delete holdouts within trc_wait_for_one_reader()	2021-07-31 08:16:11 +02:00
sched	sched/rt: Fix double enqueue caused by rt_effective_prio	2021-08-12 13:22:19 +02:00
time	timers: Move clearing of base::timer_running under base:: Lock	2021-08-12 13:22:15 +02:00
trace	tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name	2021-08-26 08:35:54 -04:00
.gitignore	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:47:37 +02:00
acct.c	kernel: acct.c: fix some kernel-doc nits	2020-10-16 11:11:19 -07:00
async.c
audit.c	audit: Remove redundant null check	2020-08-26 09:10:39 -04:00
audit.h	audit: change unnecessary globals into statics	2020-08-17 20:26:58 -04:00
audit_fsnotify.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit_tree.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
audit_watch.c	fsnotify: generalize handle_inode_event()	2020-12-30 11:54:18 +01:00
auditfilter.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
auditsc.c	audit/stable-5.9 PR 20200803	2020-08-04 14:20:26 -07:00
backtracetest.c	treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()	2020-07-30 11:15:58 -07:00
bounds.c
capability.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
compat.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c
cpu.c	cpu/hotplug: Cure the cpusets trainwreck	2021-07-19 09:44:59 +02:00
cpu_pm.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
crash_core.c	crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo	2021-06-23 14:42:52 +02:00
crash_dump.c
cred.c	cred: add missing return error code when set_cred_ucounts() failed	2021-07-14 16:56:55 +02:00
delayacct.c
dma.c
exec_domain.c
exit.c	kernel/io_uring: cancel io_uring before task works	2021-01-30 13:55:18 +01:00
extable.c
fail_function.c	fail_function: Remove a redundant mutex unlock	2020-11-19 11:58:16 -08:00
fork.c	sched/core: Initialize the idle task with preemption disabled	2021-07-14 16:55:50 +02:00
freezer.c	Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing"	2021-04-07 15:00:14 +02:00
futex.c	mm, futex: fix shared futex pgoff on shmem huge page	2021-06-30 08:47:29 -04:00
gen_kheaders.sh
groups.c	LSM: Signal to SafeSetID when setting group IDs	2020-10-13 09:17:34 -07:00
hung_task.c	kernel/hung_task.c: make type annotations consistent	2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c
jump_label.c	jump_label: Fix jump_label_text_reserved() vs __init	2021-07-20 16:05:58 +02:00
kallsyms.c	treewide: Convert macro and uses of __section(foo) to __section("foo")	2020-10-25 14:51:49 -07:00
kcmp.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c	kcov: make some symbols static	2020-08-12 10:58:02 -07:00
kexec.c	LSM: Introduce kernel_post_load_data() hook	2020-10-05 13:37:03 +02:00
kexec_core.c	kernel: kexec: remove the lock operation of system_transition_mutex	2021-02-03 23:28:37 +01:00
kexec_elf.c
kexec_file.c	kernel: kexec_file: fix error return code of kexec_calculate_store_digests()	2021-05-19 10:13:09 +02:00
kexec_internal.h
kheaders.c
kmod.c	kmod: remove redundant "be an" in the comment	2020-08-12 10:58:01 -07:00
kprobes.c	kprobes: Fix to delay the kprobes jump optimization	2021-03-04 11:38:35 +01:00
ksysfs.c
kthread.c	kthread_worker: fix return value when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()	2021-07-14 16:56:02 +02:00
latencytop.c
Makefile	kbuild: update config_data.gz only when the content of .config is changed	2021-05-11 14:47:37 +02:00
module-internal.h
module.c	module: limit enabling module.sig_enforce	2021-06-30 08:47:15 -04:00
module_signature.c	module: harden ELF info handling	2021-03-25 09:04:11 +01:00
module_signing.c	module: harden ELF info handling	2021-03-25 09:04:11 +01:00
notifier.c	notifier: Fix broken error handling pattern	2020-09-01 09:58:03 +02:00
nsproxy.c
padata.c	padata: fix possible padata_works_lock deadlock	2020-09-04 17:51:55 +10:00
panic.c	panic: don't dump stack twice on warn	2020-11-14 11:26:04 -08:00
params.c	params: Replace zero-length array with flexible-array member	2020-10-29 17:22:59 -05:00
pid.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:46:24 +01:00
pid_namespace.c	kernel/: fix repeated words in comments	2020-10-16 11:11:19 -07:00
profile.c
ptrace.c	ptrace: make ptrace() fail if the tracee changed its pid unexpectedly	2021-05-26 12:06:49 +02:00
range.c	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
reboot.c	reboot: fix overflow parsing reboot cpu number	2020-11-14 11:26:03 -08:00
regset.c	regset: kill ->get()	2020-07-27 14:31:12 -04:00
relay.c	kernel/relay.c: drop unneeded initialization	2020-10-16 11:11:22 -07:00
resource.c	kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources	2021-05-19 10:13:09 +02:00
rseq.c
scftorture.c	scftorture: Add cond_resched() to test loop	2020-08-24 18:38:38 -07:00
scs.c	mm: memcontrol: account kernel stack per node	2020-08-07 11:33:25 -07:00
seccomp.c	seccomp: Fix setting loaded filter count during TSYNC	2021-08-18 08:59:06 +02:00
signal.c	ptrace: fix task_join_group_stop() for the case when current is traced	2020-11-02 12:14:19 -08:00
smp.c	smp: Fix smp_call_function_single_async prototype	2021-05-14 09:50:46 +02:00
smpboot.c	sched/core: Initialize the idle task with preemption disabled	2021-07-14 16:55:50 +02:00
smpboot.h
softirq.c	softirq: Add debug check to __raise_softirq_irqoff()	2020-09-16 15:18:56 +02:00
stackleak.c	stackleak: let stack_erasing_sysctl take a kernel pointer buffer	2020-09-19 13:13:39 -07:00
stacktrace.c	stacktrace: Remove reliable argument from arch_stack_walk() callback	2020-09-18 14:24:16 +01:00
static_call.c	static_call: Fix static_call_text_reserved() vs __init	2021-07-20 16:05:58 +02:00
stop_machine.c	stop_machine, rcu: Mark functions as notrace	2020-10-26 12:12:27 +01:00
sys.c	Add a reference to ucounts for each cred	2021-07-14 16:55:48 +02:00
sys_ni.c	mm/madvise: introduce process_madvise() syscall: an external memory hinting API	2020-10-18 09:27:10 -07:00
sysctl-test.c
sysctl.c	sysctl.c: fix underflow value setting risk in vm_table	2021-03-17 17:06:25 +01:00
task_work.c	task_work: cleanup notification modes	2020-10-17 15:05:30 -06:00
taskstats.c	taskstats: move specifying netlink policy back to ops	2020-10-02 19:11:12 -07:00
test_kprobes.c
torture.c
tracepoint.c	tracepoint: Fix static call function vs data state mismatch	2021-08-12 13:22:12 +02:00
tsacct.c
ucount.c	Add a reference to ucounts for each cred	2021-07-14 16:55:48 +02:00
uid16.c
uid16.h
umh.c	usermodehelper: reset umask to default before executing user process	2020-10-06 10:31:52 -07:00
up.c	smp: Fix smp_call_function_single_async prototype	2021-05-14 09:50:46 +02:00
user-return-notifier.c
user.c
user_namespace.c	Add a reference to ucounts for each cred	2021-07-14 16:55:48 +02:00
usermode_driver.c	bpf: Fix umd memory leak in copy_process()	2021-03-30 14:32:03 +02:00
utsname.c
utsname_sysctl.c
watch_queue.c	watch_queue: Limit the number of watches a user can hold	2020-08-17 09:39:18 -07:00
watchdog.c	watchdog: fix barriers when printing backtraces from all CPUs	2021-05-19 10:13:00 +02:00
watchdog_hld.c
workqueue.c	workqueue: fix UAF in pwq_unbound_release_workfn()	2021-07-31 08:16:11 +02:00
workqueue_internal.h