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Mark Rutland bbb6846864 perf/core: Clear sibling list of detached events
When perf_group_dettach() is called on a group leader, it updates each
sibling's group_leader field to point to that sibling, effectively
upgrading each siblnig to a group leader. After perf_group_detach has
completed, the caller may free the leader event.

We only remove siblings from the group leader's sibling_list when the
leader has a non-empty group_node. This was fine prior to commit:

  8343aae661 ("perf/core: Remove perf_event::group_entry")

... as the sibling's sibling_list would be empty. However, now that we
use the sibling_list field as both the list head and the list entry,
this leaves each sibling with a non-empty sibling list, including the
stale leader event.

If perf_group_detach() is subsequently called on a sibling, it will
appear to be a group leader, and we'll walk the sibling_list,
potentially dereferencing these stale events. In 0day testing, this has
been observed to result in kernel panics.

Let's avoid this by always removing siblings from the sibling list when
we promote them to leaders.

Fixes: 8343aae661 ("perf/core: Remove perf_event::group_entry")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: vincent.weaver@maine.edu
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: torvalds@linux-foundation.org
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: valery.cherepennikov@intel.com
Cc: linux-tip-commits@vger.kernel.org
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: alexander.shishkin@linux.intel.com
Cc: davidcc@google.com
Cc: kan.liang@intel.com
Cc: Dmitry.Prohorov@intel.com
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lkml.kernel.org/r/20180316131741.3svgr64yibc6vsid@lakrids.cambridge.arm.com
2018-03-16 15:34:24 +01:00
..
bpf bpf: fix rcu lockdep warning for lpm_trie map_free callback 2018-02-22 21:29:12 +01:00
cgroup kernel/cpuset: current_cpuset_is_being_rebound can be boolean 2018-02-06 18:32:47 -08:00
configs KVM changes for 4.16 2018-02-10 13:16:35 -08:00
debug signal: Simplify and fix kdb_send_sig 2018-01-03 18:01:08 -06:00
events perf/core: Clear sibling list of detached events 2018-03-16 15:34:24 +01:00
gcov License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq genirq/matrix: Handle CPU offlining proper 2018-02-22 22:05:43 +01:00
livepatch Merge branch 'for-4.16/remove-immediate' into for-linus 2018-01-31 16:36:38 +01:00
locking locking/qspinlock: Ensure node->count is updated before initialising node 2018-02-13 14:50:14 +01:00
power x86/power: Fix swsusp_arch_resume prototype 2018-02-02 23:33:50 +01:00
printk Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-03-01 10:06:39 -08:00
rcu SCSI misc on 20180131 2018-01-31 11:23:28 -08:00
sched sched/cpufreq: Remove unused SUGOV_KTHREAD_PRIORITY macro 2018-02-13 13:04:03 +01:00
time timers: Forward timer base before migrating timers 2018-02-28 23:34:33 +01:00
trace Linux 4.16-rc4 2018-03-06 07:30:22 +01:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
Makefile error-injection: Support fault injection framework 2018-01-12 17:33:38 -08:00
acct.c kernel/acct.c: fix the acct->needcheck check in check_free_space() 2018-01-04 16:45:09 -08:00
async.c kernel/async.c: revert "async: simplify lowest_in_progress()" 2018-02-06 18:32:44 -08:00
audit.c Audit: remove unused audit_log_secctx function 2017-11-10 16:08:47 -05:00
audit.h audit/stable-4.15 PR 20171113 2017-11-15 13:28:48 -08:00
audit_fsnotify.c Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-05-03 11:05:15 -07:00
audit_tree.c Merge branch 'fsnotify' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2017-11-14 14:08:20 -08:00
audit_watch.c audit/stable-4.13 PR 20170816 2017-08-16 16:48:34 -07:00
auditfilter.c audit: filter PATH records keyed on filesystem magic 2017-11-10 16:08:56 -05:00
auditsc.c audit/stable-4.15 PR 20171113 2017-11-15 13:28:48 -08:00
backtracetest.c
bounds.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 cpumask: make cpumask_size() return "unsigned int" 2018-02-06 18:32:45 -08:00
configs.c
context_tracking.c
cpu.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-31 12:30:34 -08:00
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 2018-01-13 10:42:48 -08:00
crash_dump.c
cred.c doc: ReSTify credentials.txt 2017-05-18 10:30:19 -06:00
delayacct.c delayacct: Account blkio completion on the correct task 2018-01-16 03:29:36 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 kernel/exit.c: export abort() to modules 2018-01-04 16:45:09 -08:00
extable.c extable: Make init_kernel_text() global 2018-02-21 16:54:06 +01:00
fail_function.c error-injection: Support fault injection framework 2018-01-12 17:33:38 -08:00
fork.c include/linux/sched/mm.h: re-inline mmdrop() 2018-02-21 15:35:42 -08:00
freezer.c
futex.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
futex_compat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c kernel/hung_task.c: defer showing held locks 2017-05-08 17:15:10 -07:00
irq_work.c irq/work: Improve the flag definitions 2018-01-08 19:43:15 +01:00
jump_label.c extable: Make init_kernel_text() global 2018-02-21 16:54:06 +01:00
kallsyms.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk 2018-02-01 13:36:15 -08:00
kcmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kcov.c kcov: detect double association with a single task 2018-02-06 18:32:46 -08:00
kexec.c kdump: protect vmcoreinfo data under the crash memory 2017-07-12 16:26:00 -07:00
kexec_core.c x86/mm, kexec: Allow kexec to be used with SME 2017-07-18 11:38:04 +02:00
kexec_file.c resource: Provide resource struct in resource walk callback 2017-11-07 15:35:57 +01:00
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: move #ifdef CONFIG_MODULES wrapper to Makefile 2017-09-08 18:26:51 -07:00
kprobes.c kprobes: Propagate error from disarm_kprobe_ftrace() 2018-02-16 09:12:58 +01:00
ksysfs.c kexec: move vmcoreinfo out of the kernel's .bss section 2017-07-12 16:25:59 -07:00
kthread.c treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE casts 2017-11-21 16:35:54 -08:00
latencytop.c
memremap.c memremap: fix softlockup reports at teardown 2018-03-02 19:34:50 -08:00
module-internal.h
module.c Modules updates for v4.16 2018-02-07 14:29:34 -08:00
module_signing.c
notifier.c
nsproxy.c
padata.c padata: add SPDX identifier 2018-01-05 18:43:00 +11:00
panic.c kernel/panic.c: add TAINT_AUX 2017-11-17 16:10:04 -08:00
params.c kernel/params.c: improve STANDARD_PARAM_DEF readability 2017-10-03 17:54:26 -07:00
pid.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
pid_namespace.c pid: remove pidhash 2017-11-17 16:10:04 -08:00
profile.c
ptrace.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
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 kernel/reboot.c: add devm_register_reboot_notifier() 2017-11-17 16:10:04 -08:00
relay.c kernel/relay.c: limit kmalloc size to KMALLOC_MAX_SIZE 2018-02-21 15:35:43 -08:00
resource.c Merge branch 'akpm' (patches from Andrew) 2018-02-06 22:15:42 -08:00
seccomp.c - Fix seccomp GET_METADATA to deal with field sizes correctly (Tycho Andersen) 2018-02-22 10:50:24 -08:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching 2018-01-31 13:02:18 -08:00
smp.c smp/core: Use lockdep to assert IRQs are disabled/enabled 2017-11-08 11:13:50 +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 softirq: Eliminate cond_resched_rcu_qs() in favor of cond_resched() 2017-12-04 10:28:58 -08:00
stacktrace.c
stop_machine.c stop_machine: Provide stop_machine_cpuslocked() 2017-05-26 10:10:36 +02:00
sys.c fix typo in assignment of fs default overflow gid 2017-12-14 16:01:45 -06:00
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 pipe: reject F_SETPIPE_SZ with size over UINT_MAX 2018-02-06 18:32:47 -08:00
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() 2017-12-17 13:57:15 +01:00
taskstats.c pids: introduce find_get_task_by_vpid() helper 2018-02-06 18:32:46 -08:00
test_kprobes.c kprobes: Disable the jprobes test code 2017-10-20 11:02:54 +02:00
torture.c torture: Save a line in stutter_wait(): while -> for 2017-12-11 09:18:30 -08:00
tracepoint.c tracepoint: Remove smp_read_barrier_depends() from comment 2017-12-04 10:52:56 -08:00
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 kernel/umh.c: optimize 'proc_cap_handler()' 2017-11-17 16:10:01 -08:00
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 efivarfs: Limit the rate for non-root to read files 2018-02-22 10:21:02 -08:00
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2017-11-16 12:20:15 -08:00
utsname.c
utsname_sysctl.c
watchdog.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
watchdog_hld.c Merge branch 'linus' into core/urgent, to pick up dependent commits 2017-11-04 08:53:04 +01:00
workqueue.c Fixes for 4.16. I contains fixes for deadlock on runtime suspend on few 2018-02-22 08:39:26 +10:00
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