Tejun Heo aad8bbd17a memcg: fix possible use-after-free in memcg_write_event_control() ... commit 4a7ba45b1a upstream. memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a call to __file_cft() which verified that the specified file is a regular cgroupfs file before further accesses. The cftype pointer returned from __file_cft() was no longer necessary and the commit inadvertently dropped the file type check with it allowing any file to slip through. With the invarients broken, the d_name and parent accesses can now race against renames and removals of arbitrary files and cause use-after-free's. Fix the bug by resurrecting the file type check in __file_cft(). Now that cgroupfs is implemented through kernfs, checking the file operations needs to go through a layer of indirection. Instead, let's check the superblock and dentry type. Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft") Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jann Horn <jannh@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> [3.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-12-14 11:37:19 +01:00
..
bpf	bpf: Do not copy spin lock field from user in bpf_selem_alloc	2022-12-08 11:28:39 +01:00
cgroup	memcg: fix possible use-after-free in memcg_write_event_control()	2022-12-14 11:37:19 +01:00
configs	drivers/char: remove /dev/kmem for good	2021-05-07 00:26:34 -07:00
debug	lockdown: also lock down previous kgdb use	2022-05-25 09:57:37 +02:00
dma	swiotlb: max mapping size takes min align mask into account	2022-10-05 10:39:40 +02:00
entry	lockdep: Fix -Wunused-parameter for _THIS_IP_	2022-09-20 12:39:42 +02:00
events	bpf, perf: Use subprog name when reporting subprog ksymbol	2022-12-08 11:28:38 +01:00
gcov	gcov: clang: fix the buffer overflow issue	2022-12-02 17:41:09 +01:00
irq	genirq: Take the proposed affinity at face value if force==true	2022-12-02 17:41:12 +01:00
kcsan	LKMM updates:	2021-09-02 13:00:15 -07:00
livepatch	livepatch: fix race between fork and KLP transition	2022-10-26 12:34:30 +02:00
locking	lockdep: Fix -Wunused-parameter for _THIS_IP_	2022-09-20 12:39:42 +02:00
power	PM: hibernate: Allow hybrid sleep to work with s2idle	2022-11-03 23:59:17 +09:00
printk	printk: wake waiters for safe and NMI contexts	2022-06-09 10:22:49 +02:00
rcu	rcu-tasks: Convert RCU_LOCKDEP_WARN() to WARN_ONCE()	2022-10-26 12:35:29 +02:00
sched	sched/core: Fix comparison in sched_group_cookie_match()	2022-11-03 23:59:15 +09:00
time	timekeeping: contribute wall clock to rng on time change	2022-08-17 14:24:24 +02:00
trace	tracing: Free buffers when a used dynamic event is removed	2022-12-08 11:28:43 +01:00
.gitignore	.gitignore: prefix local generated files with a slash	2021-05-02 00:43:35 +09:00
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	locking/rwlock: Provide RT variant	2021-08-17 17:50:51 +02:00
Kconfig.preempt	sched/core: Disable CONFIG_SCHED_CORE by default	2021-06-28 22:43:05 +02:00
Makefile	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
acct.c	kernel/acct.c: use dedicated helper to access rlimit values	2021-09-08 11:50:26 -07:00
async.c	Revert "module, async: async_synchronize_full() on module init iff async is used"	2022-02-23 12:03:07 +01:00
audit.c	audit: improve audit queue handling when "audit=1" on cmdline	2022-02-08 18:34:03 +01:00
audit.h	audit: log AUDIT_TIME_* records only from rules	2022-04-08 14:23:06 +02:00
audit_fsnotify.c	audit: fix potential double free on error path from fsnotify_add_inode_mark	2022-08-31 17:16:33 +02:00
audit_tree.c	audit: move put_tree() to avoid trim_trees refcount underflow and UAF	2021-08-24 18:52:36 -04:00
audit_watch.c	…
auditfilter.c	lsm: separate security_task_getsecid() into subjective and objective variants	2021-03-22 15:23:32 -04:00
auditsc.c	audit: log AUDIT_TIME_* records only from rules	2022-04-08 14:23:06 +02:00
backtracetest.c	…
bounds.c	…
capability.c	…
cfi.c	cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle	2022-06-22 14:22:04 +02:00
compat.c	arch: remove compat_alloc_user_space	2021-09-08 15:32:35 -07:00
configs.c	…
context_tracking.c	…
cpu.c	random: clear fast pool, crng, and batches in cpuhp bring up	2022-05-30 09:29:09 +02:00
cpu_pm.c	PM: cpu: Make notifier chain use a raw_spinlock_t	2021-08-16 18:55:32 +02:00
crash_core.c	kernel/crash_core: suppress unknown crashkernel parameter warning	2021-12-29 12:28:49 +01:00
crash_dump.c	…
cred.c	ucounts: Base set_cred_ucounts changes on the real user	2022-02-23 12:03:20 +01:00
delayacct.c	delayacct: Add sysctl to enable at runtime	2021-05-12 11:43:25 +02:00
dma.c	…
exec_domain.c	…
exit.c	fix race between exit_itimers() and /proc/pid/timers	2022-07-21 21:24:11 +02:00
extable.c	…
fail_function.c	…
fork.c	IB/core: Fix a nested dead lock as part of ODP flow	2022-09-15 11:30:06 +02:00
freezer.c	sched: Add get_current_state()	2021-06-18 11:43:08 +02:00
futex.c	futex: Remove unused variable 'vpid' in futex_proxy_trylock_atomic()	2021-09-03 23:00:22 +02:00
gen_kheaders.sh	kbuild: clean up ${quiet} checks in shell scripts	2021-05-27 04:01:50 +09:00
groups.c	groups: simplify struct group_info allocation	2021-02-26 09:41:03 -08:00
hung_task.c	Merge branch 'akpm' (patches from Andrew)	2021-07-02 12:08:10 -07:00
iomem.c	…
irq_work.c	irq_work: Make irq_work_queue() NMI-safe again	2021-06-10 10:00:08 +02:00
jump_label.c	jump_label: Fix jump_label_text_reserved() vs __init	2021-07-05 10:46:20 +02:00
kallsyms.c	module: add printk formats to add module build ID to stacktraces	2021-07-08 11:48:22 -07:00
kcmp.c	…
kcov.c	…
kexec.c	kexec: avoid compat_alloc_user_space	2021-09-08 15:32:34 -07:00
kexec_core.c	Merge branch 'rework/printk_safe-removal' into for-linus	2021-08-30 16:36:10 +02:00
kexec_elf.c	…
kexec_file.c	ima: force signature verification when CONFIG_KEXEC_SIG is configured	2022-07-21 21:24:29 +02:00
kexec_internal.h	kexec: move machine_kexec_post_load() to public interface	2021-02-22 12:33:26 +00:00
kheaders.c	…
kmod.c	modules: add CONFIG_MODPROBE_PATH	2021-05-07 00:26:33 -07:00
kprobes.c	kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case	2022-11-26 09:24:50 +01:00
ksysfs.c	…
kthread.c	Merge branch 'akpm' (patches from Andrew)	2021-06-29 17:29:11 -07:00
latencytop.c	…
module-internal.h	…
module.c	module: fix [e_shstrndx].sh_size=0 OOB access	2022-07-12 16:35:09 +02:00
module_signature.c	…
module_signing.c	…
notifier.c	notifier: Remove atomic_notifier_call_chain_robust()	2021-08-16 18:55:32 +02:00
nsproxy.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
padata.c	padata: Remove repeated verbose license text	2021-08-27 16:30:18 +08:00
panic.c	Merge branch 'rework/printk_safe-removal' into for-linus	2021-08-30 16:36:10 +02:00
params.c	params: lift param_set_uint_minmax to common code	2021-08-16 14:42:22 +02:00
pid.c	kernel/pid.c: implement additional checks upon pidfd_create() parameters	2021-08-10 12:53:07 +02:00
pid_namespace.c	memcg: enable accounting for new namesapces and struct nsproxy	2021-09-03 09:58:12 -07:00
profile.c	profiling: fix shift too large makes kernel panic	2022-08-17 14:24:04 +02:00
ptrace.c	ptrace: Reimplement PTRACE_KILL by always sending SIGKILL	2022-06-09 10:22:29 +02:00
range.c	…
reboot.c	reboot: Add hardware protection power-off	2021-06-21 13:08:36 +01:00
regset.c	…
relay.c	…
resource.c	kernel/resource: fix kfree() of bootmem memory again	2022-04-08 14:23:43 +02:00
resource_kunit.c	…
rseq.c	rseq: Remove broken uapi field layout on 32-bit little endian	2022-04-08 14:23:10 +02:00
scftorture.c	scftorture: Fix distribution of short handler delays	2022-06-09 10:22:46 +02:00
scs.c	scs: Release kasan vmalloc poison in scs_free process	2021-11-18 19:16:29 +01:00
seccomp.c	seccomp: Invalidate seccomp mode to catch death failures	2022-02-16 12:56:38 +01:00
signal.c	signal handling: don't use BUG_ON() for debugging	2022-07-21 21:24:42 +02:00
smp.c	locking/csd_lock: Change csdlock_debug from early_param to __setup	2022-08-17 14:24:24 +02:00
smpboot.c	smpboot: Replace deprecated CPU-hotplug functions.	2021-08-10 14:57:42 +02:00
smpboot.h	…
softirq.c	genirq: Change force_irqthreads to a static key	2021-08-10 22:50:07 +02:00
stackleak.c	gcc-plugins/stackleak: Use noinstr in favor of notrace	2022-02-23 12:03:07 +01:00
stacktrace.c	stacktrace: move filter_irq_stacks() to kernel/stacktrace.c	2022-04-13 20:59:28 +02:00
static_call.c	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
static_call_inline.c	static_call: Don't make __static_call_return0 static	2022-04-13 20:59:28 +02:00
stop_machine.c	stop_machine: Add caller debug info to queue_stop_cpus_work	2021-03-23 16:01:58 +01:00
sys.c	ucounts: Move RLIMIT_NPROC handling after set_user	2022-02-23 12:03:20 +01:00
sys_ni.c	kernel/sys_ni: add compat entry for fadvise64_64	2022-08-31 17:16:33 +02:00
sysctl-test.c	kernel/sysctl-test: Remove some casts which are no-longer required	2021-06-23 16:41:24 -06:00
sysctl.c	proc: proc_skip_spaces() shouldn't think it is working on C strings	2022-12-08 11:28:45 +01:00
task_work.c	kasan: record task_work_add() call stack	2021-04-30 11:20:42 -07:00
taskstats.c	…
test_kprobes.c	…
torture.c	torture: Replace deprecated CPU-hotplug functions.	2021-08-10 10:48:07 -07:00
tracepoint.c	tracepoint: Fix kerneldoc comments	2021-08-16 11:39:51 -04:00
tsacct.c	taskstats: Cleanup the use of task->exit_code	2022-01-27 11:05:35 +01:00
ucount.c	ucounts: Handle wrapping in is_ucounts_overlimit	2022-02-23 12:03:20 +01:00
uid16.c	…
uid16.h	…
umh.c	kernel/umh.c: fix some spelling mistakes	2021-05-07 00:26:34 -07:00
up.c	A set of locking related fixes and updates:	2021-05-09 13:07:03 -07:00
user-return-notifier.c	…
user.c	fs/epoll: use a per-cpu counter for user's watches count	2021-09-08 11:50:27 -07:00
user_namespace.c	ucounts: Fix systemd LimitNPROC with private users regression	2022-03-08 19:12:42 +01:00
usermode_driver.c	Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2021-07-03 11:41:14 -07:00
utsname.c	…
utsname_sysctl.c	…
watch_queue.c	watch_queue: Fix missing locking in add_watch_to_object()	2022-08-03 12:03:43 +02:00
watchdog.c	watchdog: export lockup_detector_reconfigure	2022-08-25 11:40:43 +02:00
watchdog_hld.c	…
workqueue.c	workqueue: don't skip lockdep work dependency in cancel_work_sync()	2022-09-28 11:11:56 +02:00
workqueue_internal.h	workqueue: Assign a color to barrier work items	2021-08-17 07:49:10 -10:00