linux-stable/kernel
Jiri Olsa 2e53998790 bpf: Prevent bpf program recursion for raw tracepoint probes
commit 05b24ff9b2 upstream.

We got report from sysbot [1] about warnings that were caused by
bpf program attached to contention_begin raw tracepoint triggering
the same tracepoint by using bpf_trace_printk helper that takes
trace_printk_lock lock.

 Call Trace:
  <TASK>
  ? trace_event_raw_event_bpf_trace_printk+0x5f/0x90
  bpf_trace_printk+0x2b/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  bpf_trace_printk+0x3f/0xe0
  bpf_prog_a9aec6167c091eef_prog+0x1f/0x24
  bpf_trace_run2+0x26/0x90
  native_queued_spin_lock_slowpath+0x1c6/0x2b0
  _raw_spin_lock_irqsave+0x44/0x50
  __unfreeze_partials+0x5b/0x160
  ...

The can be reproduced by attaching bpf program as raw tracepoint on
contention_begin tracepoint. The bpf prog calls bpf_trace_printk
helper. Then by running perf bench the spin lock code is forced to
take slow path and call contention_begin tracepoint.

Fixing this by skipping execution of the bpf program if it's
already running, Using bpf prog 'active' field, which is being
currently used by trampoline programs for the same reason.

Moving bpf_prog_inc_misses_counter to syscall.c because
trampoline.c is compiled in just for CONFIG_BPF_JIT option.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reported-by: syzbot+2251879aa068ad9c960d@syzkaller.appspotmail.com
[1] https://lore.kernel.org/bpf/YxhFe3EwqchC%2FfYf@krava/T/#t
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20220916071914.7156-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-26 09:27:56 +01:00
..
bpf bpf: Prevent bpf program recursion for raw tracepoint probes 2022-11-26 09:27:56 +01:00
cgroup cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset 2022-10-21 12:38:59 +02:00
configs
debug
dma
entry
events perf: Improve missing SIGTRAP checking 2022-11-26 09:27:52 +01:00
futex
gcov gcov: support GCC 12.1 and newer compilers 2022-10-26 12:22:57 +02:00
irq
kcsan
livepatch livepatch: fix race between fork and KLP transition 2022-10-21 12:37:51 +02:00
locking
module module: tracking: Keep a record of tainted unloaded modules only 2022-10-21 12:39:02 +02:00
power PM: hibernate: Allow hybrid sleep to work with s2idle 2022-11-04 00:00:31 +09:00
printk
rcu rcu: Keep synchronize_rcu() from enabling irqs in early boot 2022-11-04 00:00:28 +09:00
sched sched/core: Fix comparison in sched_group_cookie_match() 2022-11-04 00:00:27 +09:00
time
trace bpf: Prevent bpf program recursion for raw tracepoint probes 2022-11-26 09:27:56 +01:00
.gitignore
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audit.h
audit_fsnotify.c
audit_tree.c
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auditsc.c audit: free audit_proctitle only on task exit 2022-10-21 12:38:04 +02:00
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stop_machine.c
sys.c
sys_ni.c
sysctl-test.c
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task_work.c
taskstats.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
usermode_driver.c
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watch_queue.c
watchdog.c
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workqueue.c
workqueue_internal.h