Steven Rostedt (VMware) 6d9bd13945 tracing: Check return value of __create_val_fields() before using its result ... After having a typo for writing a histogram trigger. Wrote: echo 'hist:key=pid:ts=common_timestamp.usec' > events/sched/sched_waking/trigger Instead of: echo 'hist:key=pid:ts=common_timestamp.usecs' > events/sched/sched_waking/trigger and the following crash happened: BUG: kernel NULL pointer dereference, address: 0000000000000008 #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: 4 PID: 1641 Comm: sh Not tainted 5.9.0-rc5-test+ #549 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:event_hist_trigger_func+0x70b/0x1ee0 Code: 24 08 89 d5 49 89 cc e9 8c 00 00 00 4c 89 f2 41 b9 00 10 00 00 4c 89 e1 44 89 ee 4c 89 ff e8 dc d3 ff ff 45 89 ea 4b 8b 14 d7 <f6> 42 08 04 74 17 41 8b 8f c0 00 00 00 8d 71 01 41 89 b7 c0 00 00 RSP: 0018:ffff959213d53db0 EFLAGS: 00010202 RAX: ffffffffffffffea RBX: 0000000000000000 RCX: 0000000000084c04 RDX: 0000000000000000 RSI: df7326aefebd174c RDI: 0000000000031080 RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000046 R12: ffff959211dcf690 R13: 0000000000000001 R14: ffff95925a36e370 R15: ffff959251c89800 FS: 00007fb9ea934740(0000) GS:ffff95925ab00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 00000000c976c005 CR4: 00000000001706e0 Call Trace: ? trigger_process_regex+0x78/0x110 trigger_process_regex+0xc5/0x110 event_trigger_write+0x71/0xd0 vfs_write+0xca/0x210 ksys_write+0x70/0xf0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fb9eaa29487 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 This was caused by accessing the hlist_data fields after the call to __create_val_fields() without checking if the creation succeed. Link: https://lkml.kernel.org/r/20201013154852.3abd8702@gandalf.local.home Fixes: 63a1e5de30 ("tracing: Save normal string variables") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>		2020-10-15 12:00:59 -04:00
..
blktrace.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
bpf_trace.c	bpf: Remove inline from bpf_do_trace_printk	2020-08-06 16:53:17 -07:00
bpf_trace.h	bpf: Use dedicated bpf_trace_printk event instead of trace_printk()	2020-07-13 16:55:49 -07:00
fgraph.c	fgraph: Convert ret_stack tasklist scanning to rcu	2020-09-21 21:06:02 -04:00
ftrace_internal.h
ftrace.c	ftrace: Format variable declarations of ftrace_allocate_records	2020-10-08 15:29:06 -04:00
Kconfig
kprobe_event_gen_test.c
Makefile	Kbuild updates for v5.9	2020-08-09 14:10:26 -07:00
power-traces.c
preemptirq_delay_test.c
ring_buffer_benchmark.c	sched,tracing: Convert to sched_set_fifo()	2020-07-29 11:43:53 +02:00
ring_buffer.c	Tracing updates for 5.9	2020-08-07 18:29:15 -07:00
rpm-traces.c
synth_event_gen_test.c	tracing: Add support for dynamic strings to synthetic events	2020-10-05 19:32:18 -04:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c	tracing/boot, kprobe, synth: Initialize boot-time tracing earlier	2020-09-21 21:06:04 -04:00
trace_branch.c
trace_clock.c
trace_dynevent.c	tracing: Delete repeated words in comments	2020-09-21 21:06:02 -04:00
trace_dynevent.h
trace_entries.h
trace_event_perf.c
trace_events_filter_test.h
trace_events_filter.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
trace_events_hist.c	tracing: Check return value of __create_val_fields() before using its result	2020-10-15 12:00:59 -04:00
trace_events_inject.c
trace_events_synth.c	tracing: Fix synthetic print fmt check for use of __get_str()	2020-10-08 15:29:07 -04:00
trace_events_trigger.c	tracing: Fix event trigger to accept redundant spaces	2020-06-23 21:51:40 -04:00
trace_events.c	tracing/boot: Initialize per-instance event list in early boot	2020-09-25 15:36:03 -04:00
trace_export.c
trace_functions_graph.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_functions.c	tracing: Enable creating new instance early boot	2020-09-21 21:06:04 -04:00
trace_hwlat.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_irqsoff.c
trace_kdb.c
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_kprobe.c	tracing/boot, kprobe, synth: Initialize boot-time tracing earlier	2020-09-21 21:06:04 -04:00
trace_mmiotrace.c
trace_nop.c
trace_output.c	tracing: Make the space reserved for the pid wider	2020-09-18 12:42:11 -04:00
trace_output.h
trace_preemptirq.c
trace_printk.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_probe_tmpl.h
trace_probe.c
trace_probe.h	tracing/kprobes: Support perf-style return probe	2020-09-21 21:06:03 -04:00
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest_dynamic.c
trace_selftest.c
trace_seq.c
trace_stack.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_stat.c	tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer	2020-09-18 22:17:14 -04:00
trace_stat.h
trace_synth.h	tracing: Add support for dynamic strings to synthetic events	2020-10-05 19:32:18 -04:00
trace_syscalls.c
trace_uprobe.c	tracing/uprobes: Support perf-style return probe	2020-09-21 21:06:03 -04:00
trace.c	tracing: Remove a pointless assignment	2020-10-08 15:29:06 -04:00
trace.h	tracing/boot: Initialize per-instance event list in early boot	2020-09-25 15:36:03 -04:00
tracing_map.c	tracing: Delete repeated words in comments	2020-09-21 21:06:02 -04:00
tracing_map.h