linux-stable/kernel
Zheng Yejian 2242640e9b tracing: Fix memleak due to race between current_tracer and trace
[ Upstream commit eecb91b9f9 ]

Kmemleak report a leak in graph_trace_open():

  unreferenced object 0xffff0040b95f4a00 (size 128):
    comm "cat", pid 204981, jiffies 4301155872 (age 99771.964s)
    hex dump (first 32 bytes):
      e0 05 e7 b4 ab 7d 00 00 0b 00 01 00 00 00 00 00 .....}..........
      f4 00 01 10 00 a0 ff ff 00 00 00 00 65 00 10 00 ............e...
    backtrace:
      [<000000005db27c8b>] kmem_cache_alloc_trace+0x348/0x5f0
      [<000000007df90faa>] graph_trace_open+0xb0/0x344
      [<00000000737524cd>] __tracing_open+0x450/0xb10
      [<0000000098043327>] tracing_open+0x1a0/0x2a0
      [<00000000291c3876>] do_dentry_open+0x3c0/0xdc0
      [<000000004015bcd6>] vfs_open+0x98/0xd0
      [<000000002b5f60c9>] do_open+0x520/0x8d0
      [<00000000376c7820>] path_openat+0x1c0/0x3e0
      [<00000000336a54b5>] do_filp_open+0x14c/0x324
      [<000000002802df13>] do_sys_openat2+0x2c4/0x530
      [<0000000094eea458>] __arm64_sys_openat+0x130/0x1c4
      [<00000000a71d7881>] el0_svc_common.constprop.0+0xfc/0x394
      [<00000000313647bf>] do_el0_svc+0xac/0xec
      [<000000002ef1c651>] el0_svc+0x20/0x30
      [<000000002fd4692a>] el0_sync_handler+0xb0/0xb4
      [<000000000c309c35>] el0_sync+0x160/0x180

The root cause is descripted as follows:

  __tracing_open() {  // 1. File 'trace' is being opened;
    ...
    *iter->trace = *tr->current_trace;  // 2. Tracer 'function_graph' is
                                        //    currently set;
    ...
    iter->trace->open(iter);  // 3. Call graph_trace_open() here,
                              //    and memory are allocated in it;
    ...
  }

  s_start() {  // 4. The opened file is being read;
    ...
    *iter->trace = *tr->current_trace;  // 5. If tracer is switched to
                                        //    'nop' or others, then memory
                                        //    in step 3 are leaked!!!
    ...
  }

To fix it, in s_start(), close tracer before switching then reopen the
new tracer after switching. And some tracers like 'wakeup' may not update
'iter->private' in some cases when reopen, then it should be cleared
to avoid being mistakenly closed again.

Link: https://lore.kernel.org/linux-trace-kernel/20230817125539.1646321-1-zhengyejian1@huawei.com

Fixes: d7350c3f45 ("tracing/core: make the read callbacks reentrants")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 14:52:29 +02:00
..
bpf bpf, cpumap: Handle skb as well when clean up ptr_ring 2023-08-11 12:14:15 +02:00
cgroup sched/psi: use kernfs polling functions for PSI trigger polling 2023-07-27 08:56:53 +02:00
configs Char/Misc drivers for 6.4-rc1 2023-04-27 12:07:50 -07:00
debug kdb: use srcu console list iterator 2022-12-02 11:25:00 +01:00
dma dma-remap: use kvmalloc_array/kvfree for larger dma memory remap 2023-08-23 17:32:27 +02:00
entry ptrace: Provide set/get interface for syscall user dispatch 2023-04-16 14:23:07 +02:00
events perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event() 2023-05-08 10:58:26 +02:00
futex - Prevent the leaking of a debug timer in futex_waitv() 2023-01-01 11:15:05 -08:00
gcov gcov: add support for checksum field 2022-12-21 14:31:52 -08:00
irq xen: branch for v6.4-rc4 2023-05-27 09:42:56 -07:00
kcsan kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures 2023-07-19 16:36:13 +02:00
livepatch Scheduler changes for v6.4: 2023-04-28 14:53:30 -07:00
locking locking/rtmutex: Fix task->pi_waiters integrity 2023-08-03 10:26:09 +02:00
module module/decompress: Fix error checking on zstd decompression 2023-06-01 14:36:46 -07:00
power PM: QoS: Restore support for default value on frequency QoS 2023-07-23 13:54:11 +02:00
printk - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
rcu rcu: Mark additional concurrent load from ->cpu_no_qs.b.exp 2023-07-27 08:56:48 +02:00
sched sched/psi: use kernfs polling functions for PSI trigger polling 2023-07-27 08:56:53 +02:00
time posix-timers: Ensure timer ID search-loop limit is valid 2023-07-27 08:56:45 +02:00
trace tracing: Fix memleak due to race between current_tracer and trace 2023-08-30 14:52:29 +02:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
Makefile modules-6.4-rc1 2023-04-27 16:36:55 -07:00
acct.c acct: fix potential integer overflow in encode_comp_t() 2022-11-30 16:13:18 -08:00
async.c
audit.c audit: use time_after to compare time 2022-08-29 19:47:03 -04:00
audit.h audit: remove selinux_audit_rule_update() declaration 2022-09-07 11:30:15 -04:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-22 18:50:06 -04:00
audit_tree.c audit: use fsnotify group lock helpers 2022-04-25 14:37:28 +02:00
audit_watch.c audit_init_parent(): constify path 2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c capability: just use a 'u64' instead of a 'u32[2]' array 2023-03-01 10:01:22 -08:00
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c sched_getaffinity: don't assume 'cpumask_size()' is fully initialized 2023-03-14 19:32:38 -07:00
configs.c
context_tracking.c context_tracking: Fix noinstr vs KASAN 2023-01-13 11:48:18 +01:00
cpu.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
cpu_pm.c cpuidle, cpu_pm: Remove RCU fiddling from cpu_pm_{enter,exit}() 2023-01-13 11:48:15 +01:00
crash_core.c mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
crash_dump.c
cred.c cred: Do not default to init_cred in prepare_kernel_cred() 2022-11-01 10:04:52 -07:00
delayacct.c delayacct: track delays from IRQ/SOFTIRQ 2023-04-18 16:39:34 -07:00
dma.c
exec_domain.c
exit.c fork, vhost: Use CLONE_THREAD to fix freezer/ps regression 2023-06-01 17:15:33 -04:00
extable.c context_tracking: Take NMI eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
fail_function.c kernel/fail_function: fix memory leak with using debugfs_lookup() 2023-02-08 13:36:22 +01:00
fork.c fork: lock VMAs of the parent process when forking 2023-07-11 06:31:05 +02:00
freezer.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gen_kheaders.sh kheaders: use standard naming for the temporary directory 2023-01-22 23:43:34 +09:00
groups.c security: Add LSM hook to setgroups() syscall 2022-07-15 18:21:49 +00:00
hung_task.c kernel/hung_task.c: set some hung_task.c variables storage-class-specifier to static 2023-04-08 13:45:37 -07:00
iomem.c
irq_work.c trace: Add trace_ipi_send_cpu() 2023-03-24 11:01:29 +01:00
jump_label.c jump_label: Prevent key->enabled int overflow 2022-12-01 15:53:05 -08:00
kallsyms.c kallsyms: strip LTO-only suffixes from promoted global functions 2023-07-27 08:56:54 +02:00
kallsyms_internal.h kallsyms: Reduce the memory occupied by kallsyms_seqs_of_names[] 2022-11-12 18:47:36 -08:00
kallsyms_selftest.c kallsyms: Delete an unused parameter related to {module_}kallsyms_on_each_symbol() 2023-03-19 13:27:19 -07:00
kallsyms_selftest.h kallsyms: Add self-test facility 2022-11-15 00:42:02 -08:00
kcmp.c
kcov.c mm: replace vma->vm_flags direct modifications with modifier calls 2023-02-09 16:51:39 -08:00
kexec.c kexec: introduce sysctl parameters kexec_load_limit_* 2023-02-02 22:50:05 -08:00
kexec_core.c kexec: fix a memory leak in crash_shrink_memory() 2023-07-19 16:35:28 +02:00
kexec_elf.c
kexec_file.c kexec: support purgatories with .text.hot sections 2023-06-12 11:31:50 -07:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kheaders.c kheaders: Use array declaration instead of char 2023-03-24 20:10:59 -07:00
kprobes.c x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range 2023-02-21 08:49:16 +09:00
ksysfs.c kernel/ksysfs.c: use sysfs_emit for sysfs show handlers 2023-03-24 17:09:14 +01:00
kthread.c - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of 2023-04-27 19:42:02 -07:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
module_signature.c
notifier.c notifiers: add tracepoints to the notifiers infrastructure 2023-04-08 13:45:38 -07:00
nsproxy.c convert setns(2) to fdget()/fdput() 2023-04-20 22:55:35 -04:00
padata.c padata: use alignment when calculating the number of worker threads 2023-03-14 17:06:44 +08:00
panic.c cpu: Mark nmi_panic_self_stop() __noreturn 2023-04-14 17:31:26 +02:00
params.c module: make module_ktype structure constant 2023-03-09 12:55:15 -08:00
pid.c pid: add pidfd_prepare() 2023-04-03 11:16:56 +02:00
pid_namespace.c kernel: pid_namespace: simplify sysctls with register_sysctl() 2023-05-02 19:23:29 -07:00
pid_sysctl.h kernel: pid_namespace: simplify sysctls with register_sysctl() 2023-05-02 19:23:29 -07:00
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c ptrace: Provide set/get interface for syscall user dispatch 2023-04-16 14:23:07 +02:00
range.c
reboot.c kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode 2022-10-04 15:59:36 +02:00
regset.c
relay.c relayfs: fix out-of-bounds access in relay_file_read 2023-05-02 17:23:27 -07:00
resource.c dax/kmem: Fix leak of memory-hotplug resources 2023-02-17 14:58:01 -08:00
resource_kunit.c
rseq.c rseq: Extend struct rseq with per-memory-map concurrency ID 2022-12-27 12:52:12 +01:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-04-11 17:07:29 -07:00
scs.c scs: add support for dynamic shadow call stacks 2022-11-09 18:06:35 +00:00
seccomp.c seccomp: simplify sysctls with register_sysctl_init() 2023-04-13 11:49:20 -07:00
signal.c mm: suppress mm fault logging if fatal signal already pending 2023-08-03 10:25:53 +02:00
smp.c trace,smp: Trace all smp_function_call*() invocations 2023-03-24 11:01:30 +01:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c softirq: Add trace points for tasklet entry/exit 2023-04-15 10:17:16 +02:00
stackleak.c stackleak: allow to specify arch specific stackleak poison function 2023-04-20 11:36:35 +02:00
stacktrace.c
static_call.c
static_call_inline.c static_call: Add call depth tracking support 2022-10-17 16:41:16 +02:00
stop_machine.c Scheduler changes in this cycle were: 2022-05-24 11:11:13 -07:00
sys.c prctl: move PR_GET_AUXV out of PR_MCE_KILL 2023-07-27 08:56:33 +02:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-20 15:17:45 -07:00
sysctl-test.c kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred} 2022-09-08 16:56:45 -07:00
sysctl.c mm: compaction: move compaction sysctl to its own file 2023-04-13 11:49:35 -07:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
torture.c torture: Fix hang during kthread shutdown phase 2023-01-05 12:10:35 -08:00
tracepoint.c tracepoint: Allow livepatch module add trace event 2023-02-18 14:34:36 -05:00
tsacct.c taskstats: version 12 with thread group and exe info 2022-04-29 14:38:03 -07:00
ucount.c ucounts: Split rlimit and ucount values and max values 2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c umh: simplify the capability pointer logic 2023-03-03 16:18:19 -08:00
up.c
user-return-notifier.c
user.c kernel/user: Allow user_struct::locked_vm to be usable for iommufd 2022-11-30 20:16:49 -04:00
user_namespace.c userns: fix a struct's kernel-doc notation 2023-02-02 22:50:04 -08:00
usermode_driver.c blob_to_mnt(): kern_unmount() is needed to undo kern_mount() 2022-05-19 23:25:47 -04:00
utsname.c
utsname_sysctl.c utsname: simplify one-level sysctl registration for uts_kern_table 2023-04-13 11:49:35 -07:00
vhost_task.c vhost: Fix worker hangs due to missed wake up calls 2023-06-08 15:43:09 -04:00
watch_queue.c watch_queue: prevent dangling pipe pointer 2023-07-19 16:36:53 +02:00
watchdog.c watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails 2023-07-19 16:35:33 +02:00
watchdog_hld.c watchdog/hardlockup: rename some "NMI watchdog" constants/function 2023-07-19 16:35:32 +02:00
workqueue.c workqueue: clean up WORK_* constant types, clarify masking 2023-06-23 12:08:14 -07:00
workqueue_internal.h