linux-stable/kernel/trace
Steven Rostedt (Google) ba53c21ce9 tracing/eprobes: Do not allow eprobes to use $stack, or % for regs
commit 2673c60ee6 upstream.

While playing with event probes (eprobes), I tried to see what would
happen if I attempted to retrieve the instruction pointer (%rip) knowing
that event probes do not use pt_regs. The result was:

 BUG: kernel NULL pointer dereference, address: 0000000000000024
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01
v03.03 07/14/2016
 RIP: 0010:get_event_field.isra.0+0x0/0x50
 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8
50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24
8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74
 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086
 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000
 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000
 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8
 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff916c9ea40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0
 Call Trace:
  <TASK>
  get_eprobe_size+0xb4/0x640
  ? __mod_node_page_state+0x72/0xc0
  __eprobe_trace_func+0x59/0x1a0
  ? __mod_lruvec_page_state+0xaa/0x1b0
  ? page_remove_file_rmap+0x14/0x230
  ? page_remove_rmap+0xda/0x170
  event_triggers_call+0x52/0xe0
  trace_event_buffer_commit+0x18f/0x240
  trace_event_raw_event_sched_wakeup_template+0x7a/0xb0
  try_to_wake_up+0x260/0x4c0
  __wake_up_common+0x80/0x180
  __wake_up_common_lock+0x7c/0xc0
  do_notify_parent+0x1c9/0x2a0
  exit_notify+0x1a9/0x220
  do_exit+0x2ba/0x450
  do_group_exit+0x2d/0x90
  __x64_sys_exit_group+0x14/0x20
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Obviously this is not the desired result.

Move the testing for TPARG_FL_TPOINT which is only used for event probes
to the top of the "$" variable check, as all the other variables are not
used for event probes. Also add a check in the register parsing "%" to
fail if an event probe is used.

Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:57 +02:00
..
blktrace.c blktrace: Trace remapped requests correctly 2022-08-17 14:23:13 +02:00
bpf_trace.c bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem. 2022-05-01 17:22:26 +02:00
bpf_trace.h
error_report-traces.c tracing: add error_report_end trace point 2021-02-26 09:41:02 -08:00
fgraph.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
ftrace.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
ftrace_internal.h
Kconfig tracing: Simplify the Kconfig dependency of FTRACE 2021-08-16 11:37:20 -04:00
kprobe_event_gen_test.c
Makefile tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
pid_list.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
pid_list.h tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
power-traces.c
preemptirq_delay_test.c
ring_buffer.c ring-buffer: Protect ring_buffer_reset() from reentrancy 2021-11-18 19:16:03 +01:00
ring_buffer_benchmark.c
rpm-traces.c
synth_event_gen_test.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace.c tracing: Fix return value of trace_pid_write() 2022-07-29 17:25:29 +02:00
trace.h tracing: Add '__rel_loc' using trace event macros 2022-08-17 14:24:26 +02:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c tracing: Initialize integer variable to prevent garbage return value 2022-06-09 10:23:21 +02:00
trace_branch.c
trace_clock.c tracing: Do no increment trace_clock_global() by one 2021-06-18 09:10:00 -04:00
trace_dynevent.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_dynevent.h tracing: Add DYNAMIC flag for dynamic events 2021-08-18 18:10:32 -04:00
trace_entries.h trace: Add timerlat tracer 2021-06-25 19:57:24 -04:00
trace_eprobe.c tracing: Fix misspelling of "missing" 2021-10-29 09:54:14 -04:00
trace_event_perf.c tracing/perf: Fix double put of trace event when init fails 2022-08-25 11:39:57 +02:00
trace_events.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
trace_events_filter.c tracing: Add ustring operation to filtering string pointers 2022-03-08 19:12:33 +01:00
trace_events_filter_test.h
trace_events_hist.c tracing/histograms: Fix memory leak problem 2022-07-21 21:24:11 +02:00
trace_events_inject.c
trace_events_synth.c tracing: Do not let synth_events block other dyn_event systems during create 2022-03-08 19:12:35 +01:00
trace_events_trigger.c tracing: Have traceon and traceoff trigger honor the instance 2022-03-02 11:48:03 +01:00
trace_export.c
trace_functions.c tracing: Add "func_no_repeats" option for function tracing 2021-04-15 14:50:02 -04:00
trace_functions_graph.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_hwlat.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_irqsoff.c
trace_kdb.c kdb: Rename members of struct kdbtab_t 2021-07-27 17:05:06 +01:00
trace_kprobe.c tracing/kprobes: Check whether get_kretprobe() returns NULL in kretprobe_dispatcher() 2022-06-29 09:03:20 +02:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c
trace_nop.c
trace_osnoise.c tracing/osnoise: Force quiescent states while tracing 2022-03-16 14:23:43 +01:00
trace_output.c tracing: Add migrate-disabled counter to tracing output. 2021-09-03 19:42:35 -04:00
trace_output.h
trace_preemptirq.c
trace_printk.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_probe.c tracing/eprobes: Do not allow eprobes to use $stack, or % for regs 2022-08-25 11:39:57 +02:00
trace_probe.h tracing: Add a probe that attaches to trace events 2021-08-20 14:18:40 -04:00
trace_probe_tmpl.h tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs 2021-08-19 09:09:03 -04:00
trace_recursion_record.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_sched_switch.c
trace_sched_wakeup.c tracing: Change variable type as bool for clean-up 2021-06-30 09:19:14 -04:00
trace_selftest.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_selftest_dynamic.c
trace_seq.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_stack.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_stat.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_stat.h
trace_synth.h tracing: synth events: increase max fields count 2021-09-08 15:29:16 -04:00
trace_syscalls.c tracing: Make tp_printk work on syscall tracepoints 2022-06-14 18:36:14 +02:00
trace_uprobe.c tracing/uprobes: Check the return value of kstrdup() for tu->filename 2022-03-08 19:12:38 +01:00
tracing_map.c tracing: Fix a kmemleak false positive in tracing_map 2021-12-17 10:30:16 +01:00
tracing_map.h