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Zhihao Cheng 677e362ba8 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>
2021-10-06 15:31:15 +02:00
..
blktrace.c
blktrace: Fix uaf in blk_trace access after removing by sysfs
2021-10-06 15:31:15 +02:00
bpf_trace.c
tracepoint: Add tracepoint_probe_register_may_exist() for BPF tracing
2021-07-20 16:15:42 +02:00
ftrace.c
ftrace: Do not blindly read the ip address in ftrace_bug()
2021-06-16 11:55:02 +02:00
Kconfig
tracing/kprobes: Do the notrace functions check without kprobes on ftrace
2021-01-19 18:22:35 +01:00
Makefile
tracing: Allow gcov profiling on only ftrace subsystem
2018-08-21 09:11:49 -04:00
power-traces.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
preemptirq_delay_test.c
tracing: Use trace_clock_local() for looping in preemptirq_delay_test.c
2018-10-17 15:35:33 -04:00
ring_buffer_benchmark.c
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
ring_buffer.c
tracing: Fix bug in rb_per_cpu_empty() that might cause deadloop.
2021-07-28 11:13:50 +02:00
rpm-traces.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
trace_benchmark.c
rcu: Rename cond_resched_rcu_qs() to cond_resched_tasks_rcu_qs()
2018-05-15 10:27:29 -07:00
trace_benchmark.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00
trace_branch.c
Revert "x86/uaccess, ftrace: Fix ftrace_likely_update() vs. SMAP"
2019-07-03 13:14:41 +02:00
trace_clock.c
tracing: Do no increment trace_clock_global() by one
2021-06-30 08:48:23 -04:00
trace_entries.h
tracing: Set kernel_stack's caller size properly
2020-10-01 13:14:31 +02:00
trace_event_perf.c
tracing: Fix race in perf_trace_buf initialization
2019-10-29 09:20:03 +01:00
trace_events_filter_test.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00
trace_events_filter.c
tracing: Have error path in predicate_parse() free its allocated memory
2020-08-05 10:05:59 +02:00
trace_events_hist.c
tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name
2021-08-26 08:36:47 -04:00
trace_events_trigger.c
tracing: Fix event trigger to accept redundant spaces
2020-06-30 23:17:17 -04:00
trace_events.c
tracing: Do not count ftrace events in top level enable output
2021-02-23 15:00:55 +01:00
trace_export.c
tracing: Add trigger file for trace_markers tracefs/ftrace/print
2018-05-29 08:28:53 -04:00
trace_functions_graph.c
tracing/fgraph: Fix set_graph_function from showing interrupts
2018-12-08 12:59:07 +01:00
trace_functions.c
tracing: Update stack trace skipping for ORC unwinder
2018-01-23 15:57:00 -05:00
trace_hwlat.c
tracing: Remove WARN_ON in start_thread()
2020-12-08 10:18:55 +01:00
trace_irqsoff.c
tracing/fgraph: Fix set_graph_function from showing interrupts
2018-12-08 12:59:07 +01:00
trace_kdb.c
tracing: Silence GCC 9 array bounds warning
2019-06-25 11:35:52 +08:00
trace_kprobe_selftest.c
selftest/ftrace: Move kprobe selftest function to separate compile unit
2018-07-30 18:41:04 -04:00
trace_kprobe_selftest.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00
trace_kprobe.c
tracing/kprobe: Fix kprobe_on_func_entry() modification
2021-09-26 13:39:47 +02:00
trace_mmiotrace.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
trace_nop.c
License cleanup: add SPDX GPL-2.0 license identifier to files with no license
2017-11-02 11:10:55 +01:00
trace_output.c
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
trace_output.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00
trace_preemptirq.c
lockdep: fix order in trace_hardirqs_off_caller()
2020-10-01 13:14:50 +02:00
trace_printk.c
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
trace_probe.c
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
trace_probe.h
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
trace_sched_switch.c
tracing: Fix sched switch start/stop refcount racy updates
2020-02-11 04:33:55 -08:00
trace_sched_wakeup.c
kernel/trace: Fix do not unregister tracepoints when register sched_migrate_task fail
2020-01-14 20:06:59 +01:00
trace_selftest_dynamic.c
ftrace: Mark function tracer test functions noinline/noclone
2018-01-23 15:57:29 -05:00
trace_selftest.c
ftrace: Handle tracing when switching between context
2020-11-10 12:35:58 +01:00
trace_seq.c
tracing: Add SPDX License format tags to tracing files
2018-08-16 19:08:06 -04:00
trace_stack.c
tracing: Have stack tracer compile when MCOUNT_INSN_SIZE is not defined
2020-01-14 20:06:59 +01:00
trace_stat.c
tracing: Fix very unlikely race of registering two stat tracers
2020-02-24 08:34:39 +01:00
trace_stat.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00
trace_syscalls.c
Tracing updates for 4.15:
2017-11-17 14:58:01 -08:00
trace_uprobe.c
tracing/uprobes: Fix output for multiple string arguments
2019-02-20 10:25:48 +01:00
trace.c
tracing/histogram: Rename "cpu" to "common_cpu"
2021-08-12 13:19:42 +02:00
trace.h
tracing: Fix userstacktrace option for instances
2020-12-11 13:25:03 +01:00
tracing_map.c
tracing: Have the histogram compare functions convert to u64 first
2020-01-09 10:19:02 +01:00
tracing_map.h
tracing: Fix SPDX format headers to use C++ style comments
2018-08-16 19:08:06 -04:00