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Zhihao Cheng 3815fe7371 blktrace: Fix uaf in blk_trace access after removing by sysfs 
[ Upstream commit 5afedf670caf30a2b5a52da96eb7eac7dee6a9c9 ]

There is an use-after-free problem triggered by following process:

      P1(sda)				P2(sdb)
			echo 0 > /sys/block/sdb/trace/enable
			  blk_trace_remove_queue
			    synchronize_rcu
			    blk_trace_free
			      relay_close
rcu_read_lock
__blk_add_trace
  trace_note_tsk
  (Iterate running_trace_list)
			        relay_close_buf
				  relay_destroy_buf
				    kfree(buf)
    trace_note(sdb's bt)
      relay_reserve
        buf->offset <- nullptr deference (use-after-free) !!!
rcu_read_unlock

[  502.714379] BUG: kernel NULL pointer dereference, address:
0000000000000010
[  502.715260] #PF: supervisor read access in kernel mode
[  502.715903] #PF: error_code(0x0000) - not-present page
[  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
[  502.717252] Oops: 0000 [#1] SMP
[  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
[  502.732872] Call Trace:
[  502.733193]  __blk_add_trace.cold+0x137/0x1a3
[  502.733734]  blk_add_trace_rq+0x7b/0xd0
[  502.734207]  blk_add_trace_rq_issue+0x54/0xa0
[  502.734755]  blk_mq_start_request+0xde/0x1b0
[  502.735287]  scsi_queue_rq+0x528/0x1140
...
[  502.742704]  sg_new_write.isra.0+0x16e/0x3e0
[  502.747501]  sg_ioctl+0x466/0x1100

Reproduce method:
  ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sda, BLKTRACESTART)
  ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sdb, BLKTRACESTART)

  echo 0 > /sys/block/sdb/trace/enable &
  // Add delay(mdelay/msleep) before kernel enters blk_trace_free()

  ioctl$SG_IO(/dev/sda, SG_IO, ...)
  // Enters trace_note_tsk() after blk_trace_free() returned
  // Use mdelay in rcu region rather than msleep(which may schedule out)

Remove blk_trace from running_list before calling blk_trace_free() by
sysfs if blk_trace is at Blktrace_running state.

Fixes: c71a896154119f ("blktrace: add ftrace plugin")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-30 10:11:05 +02:00
..
blktrace.c
blktrace: Fix uaf in blk_trace access after removing by sysfs
2021-09-30 10:11:05 +02:00
bpf_trace.c
bpf: Add lockdown check for probe_write_user helper
2021-08-15 14:00:25 +02:00
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: Initialize tracing_graph_pause at task creation
2021-02-10 09:29:16 +01:00
ftrace_internal.h
x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up
2020-05-12 18:24:34 -04:00
ftrace.c
ftrace: Do not blindly read the ip address in ftrace_bug()
2021-06-16 12:01:40 +02:00
Kconfig
tracing/kprobes: Do the notrace functions check without kprobes on ftrace
2021-01-19 18:27:19 +01:00
kprobe_event_gen_test.c
tracing: Add kprobe event command generation test module
2020-01-30 09:46:28 -05:00
Makefile
Kbuild updates for v5.9
2020-08-09 14:10:26 -07:00
power-traces.c
…
preemptirq_delay_test.c
tracing: Wait for preempt irq delay thread to execute
2020-05-11 17:00:34 -04:00
ring_buffer_benchmark.c
sched,tracing: Convert to sched_set_fifo()
2020-07-29 11:43:53 +02:00
ring_buffer.c
tracing: Fix bug in rb_per_cpu_empty() that might cause deadloop.
2021-07-28 14:35:45 +02:00
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: Use pr_warn instead of pr_warning
2019-10-18 15:01:57 +02:00
trace_benchmark.h
…
trace_boot.c
tracing/boot: Fix a hist trigger dependency for boot time tracing
2021-09-22 12:28:03 +02:00
trace_branch.c
tracing: Make struct ring_buffer less ambiguous
2020-01-13 13:19:38 -05:00
trace_clock.c
tracing: Do no increment trace_clock_global() by one
2021-06-23 14:42:50 +02:00
trace_dynevent.c
tracing: Delete repeated words in comments
2020-09-21 21:06:02 -04:00
trace_dynevent.h
tracing: Remove check_arg() callbacks from dynevent args
2020-02-01 13:09:23 -05:00
trace_entries.h
tracing: Make ftrace packed events have align of 1
2020-06-16 21:21:02 -04:00
trace_event_perf.c
Merge branch 'perf/urgent' into perf/core, to pick up fixes
2019-10-28 12:38:26 +01:00
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 / histogram: Fix NULL pointer dereference on strcmp() on NULL event name
2021-08-26 08:35:54 -04:00
trace_events_inject.c
tracing: Initialize val to zero in parse_entry of inject code
2020-01-02 19:04:57 -05:00
trace_events_synth.c
tracing: Make -ENOMEM the default error for parse_synth_field()
2020-11-02 15:58:32 -05:00
trace_events_trigger.c
tracing: Fix event trigger to accept redundant spaces
2020-06-23 21:51:40 -04:00
trace_events.c
tracing: Do not count ftrace events in top level enable output
2021-02-17 11:02:20 +01:00
trace_export.c
treewide: Convert macro and uses of __section(foo) to __section("foo")
2020-10-25 14:51:49 -07:00
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: Remove WARN_ON in start_thread()
2020-11-30 21:43:07 -05:00
trace_irqsoff.c
tracing: Use pause-on-trace with the latency tracers
2021-02-10 09:29:16 +01:00
trace_kdb.c
tracing: Rename trace_buffer to array_buffer
2020-01-13 13:19:38 -05:00
trace_kprobe_selftest.c
…
trace_kprobe_selftest.h
…
trace_kprobe.c
tracing/probes: Reject events which have the same name of existing one
2021-09-22 12:28:00 +02:00
trace_mmiotrace.c
tracing: Make struct ring_buffer less ambiguous
2020-01-13 13:19:38 -05:00
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
lockdep: fix order in trace_hardirqs_off_caller()
2020-09-14 10:08:07 +02:00
trace_printk.c
Updates for tracing and bootconfig:
2020-10-15 15:51:28 -07:00
trace_probe_tmpl.h
…
trace_probe.c
tracing/probes: Reject events which have the same name of existing one
2021-09-22 12:28:00 +02:00
trace_probe.h
tracing/probes: Reject events which have the same name of existing one
2021-09-22 12:28:00 +02:00
trace_sched_switch.c
tracing: Fix sched switch start/stop refcount racy updates
2020-01-30 09:46:10 -05:00
trace_sched_wakeup.c
tracing: Make struct ring_buffer less ambiguous
2020-01-13 13:19:38 -05:00
trace_selftest_dynamic.c
…
trace_selftest.c
tracing: Disable ftrace selftests when any tracer is running
2020-12-30 11:54:28 +01:00
trace_seq.c
tracing: Remove unused TRACE_SEQ_BUF_USED
2020-01-21 18:39:54 -05:00
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
tracing: Use generic type for comparator function
2019-11-14 13:15:11 -05:00
trace_synth.h
tracing: Synthetic event field_pos is an index not a boolean
2021-07-28 14:35:45 +02:00
trace_syscalls.c
Tracing updates:
2020-02-06 07:12:11 +00:00
trace_uprobe.c
tracing/probes: Reject events which have the same name of existing one
2021-09-22 12:28:00 +02:00
trace.c
tracing: Fix NULL pointer dereference in start_creating
2021-08-12 13:22:12 +02:00
trace.h
tracing: Disable ftrace selftests when any tracer is running
2020-12-30 11:54:28 +01:00
tracing_map.c
tracing: Delete repeated words in comments
2020-09-21 21:06:02 -04:00
tracing_map.h
…