Namhyung Kim d879d0b8c1 ftrace: Fix function pid filter on instances ... When function tracer has a pid filter, it adds a probe to sched_switch to track if current task can be ignored. The probe checks the ftrace_ignore_pid from current tr to filter tasks. But it misses to delete the probe when removing an instance so that it can cause a crash due to the invalid tr pointer (use-after-free). This is easily reproducible with the following: # cd /sys/kernel/debug/tracing # mkdir instances/buggy # echo $$ > instances/buggy/set_ftrace_pid # rmdir instances/buggy ============================================================================ BUG: KASAN: use-after-free in ftrace_filter_pid_sched_switch_probe+0x3d/0x90 Read of size 8 by task kworker/0:1/17 CPU: 0 PID: 17 Comm: kworker/0:1 Tainted: G B 4.11.0-rc3 #198 Call Trace: dump_stack+0x68/0x9f kasan_object_err+0x21/0x70 kasan_report.part.1+0x22b/0x500 ? ftrace_filter_pid_sched_switch_probe+0x3d/0x90 kasan_report+0x25/0x30 __asan_load8+0x5e/0x70 ftrace_filter_pid_sched_switch_probe+0x3d/0x90 ? fpid_start+0x130/0x130 __schedule+0x571/0xce0 ... To fix it, use ftrace_clear_pids() to unregister the probe. As instance_rmdir() already updated ftrace codes, it can just free the filter safely. Link: http://lkml.kernel.org/r/20170417024430.21194-2-namhyung@kernel.org Fixes: 0c8916c342 ("tracing: Add rmdir to remove multibuffer instances") Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>		2017-04-17 16:44:23 -04:00
..
blktrace.c	blktrace: use existing disk debugfs directory	2017-02-02 10:20:16 -07:00
bpf_trace.c	bpf: mark all registered map/prog types as __ro_after_init	2017-02-17 13:40:04 -05:00
ftrace.c	ftrace: Fix function pid filter on instances	2017-04-17 16:44:23 -04:00
Kconfig	perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS	2017-03-01 10:26:39 +01:00
Makefile	perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS	2017-03-01 10:26:39 +01:00
power-traces.c
ring_buffer.c	ring-buffer: Fix return value check in test_ringbuffer()	2017-04-05 09:36:52 -04:00
ring_buffer_benchmark.c	sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h>	2017-03-02 08:42:27 +01:00
rpm-traces.c
trace.c	ftrace: Fix function pid filter on instances	2017-04-17 16:44:23 -04:00
trace.h	ftrace: Fix function pid filter on instances	2017-04-17 16:44:23 -04:00
trace_benchmark.c	tracing: Fix return value check in trace_benchmark_reg()	2017-02-15 09:02:27 -05:00
trace_benchmark.h	tracing: Have the reg function allow to fail	2016-12-09 09:13:30 -05:00
trace_branch.c	tracing: Add the constant count for branch tracer	2017-01-19 08:57:41 -05:00
trace_clock.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
trace_entries.h	tracing: Add the constant count for branch tracer	2017-01-19 08:57:41 -05:00
trace_event_perf.c
trace_events.c	tracing: Have system enable return error if one of the events fail	2016-12-09 09:15:41 -05:00
trace_events_filter.c
trace_events_filter_test.h
trace_events_hist.c	sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>	2017-03-02 08:42:38 +01:00
trace_events_trigger.c	sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>	2017-03-02 08:42:38 +01:00
trace_export.c
trace_functions.c
trace_functions_graph.c	tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too	2016-12-09 09:21:35 -05:00
trace_hwlat.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h>	2017-03-02 08:42:27 +01:00
trace_irqsoff.c	clocksource: Use a plain u64 instead of cycle_t	2016-12-25 11:04:12 +01:00
trace_kdb.c
trace_kprobe.c	sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>	2017-03-02 08:42:38 +01:00
trace_mmiotrace.c
trace_nop.c
trace_output.c	sched/headers: Prepare for new header dependencies before moving code to <linux/sched/mm.h>	2017-03-02 08:42:28 +01:00
trace_output.h
trace_printk.c
trace_probe.c	tracing/probes: Fix a warning message to show correct maximum length	2017-02-15 10:32:48 -05:00
trace_probe.h	perf/core: Rename CONFIG_[UK]PROBE_EVENT to CONFIG_[UK]PROBE_EVENTS	2017-03-01 10:26:39 +01:00
trace_sched_switch.c
trace_sched_wakeup.c	clocksource: Use a plain u64 instead of cycle_t	2016-12-25 11:04:12 +01:00
trace_selftest.c	sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h>	2017-03-02 08:42:27 +01:00
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c	scripts/spelling.txt: add "overide" pattern and fix typo instances	2017-03-09 17:01:09 -08:00
trace_stat.c
trace_stat.h
trace_syscalls.c
trace_uprobe.c	sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h>	2017-03-02 08:42:38 +01:00
tracing_map.c
tracing_map.h