BMC/Intel-BMC/linux.git/kernel/trace, branch dev-5.14-intel

blktrace: Fix uaf in blk_trace access after removing by sysfs

2021-09-30T08:13:03+00:00

[ 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 Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

tracing/boot: Fix to loop on only subkeys

2021-09-26T12:10:19+00:00

[ Upstream commit cfd799837dbc48499abb05d1891b3d9992354d3a ] Since the commit e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key") allows to co-exist a value node and key nodes under a node, xbc_node_for_each_child() is not only returning key node but also a value node. In the boot-time tracing using xbc_node_for_each_child() to iterate the events, groups and instances, but those must be key nodes. Thus it must use xbc_node_for_each_subkey(). Link: https://lkml.kernel.org/r/163112988361.74896.2267026262061819145.stgit@devnote2 Fixes: e5efaeb8a8f5 ("bootconfig: Support mixing a value and subkeys under a key") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing/boot: Fix a hist trigger dependency for boot time tracing

2021-09-22T10:39:29+00:00

[ Upstream commit 6fe7c745f2acb73e4cc961d7f91125eef5a8861f ] Fixes a build error when CONFIG_HIST_TRIGGERS=n with boot-time tracing. Since the trigger_process_regex() is defined only when CONFIG_HIST_TRIGGERS=y, if it is disabled, the 'actions' event option also must be disabled. Link: https://lkml.kernel.org/r/162856123376.203126.582144262622247352.stgit@devnote2 Fixes: 81a59555ff15 ("tracing/boot: Add per-event settings") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing/probes: Reject events which have the same name of existing one

2021-09-22T10:39:26+00:00

[ Upstream commit 8e242060c6a4947e8ae7d29794af6a581db08841 ] Since kprobe_events and uprobe_events only check whether the other same-type probe event has the same name or not, if the user gives the same name of the existing tracepoint event (or the other type of probe events), it silently fails to create the tracefs entry (but registered.) as below. /sys/kernel/tracing # ls events/task/task_rename enable filter format hist id trigger /sys/kernel/tracing # echo p:task/task_rename vfs_read >> kprobe_events [ 113.048508] Could not create tracefs 'task_rename' directory /sys/kernel/tracing # cat kprobe_events p:task/task_rename vfs_read To fix this issue, check whether the existing events have the same name or not in trace_probe_register_event_call(). If exists, it rejects to register the new event. Link: https://lkml.kernel.org/r/162936876189.187130.17558311387542061930.stgit@devnote2 Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

tracing/osnoise: Fix missed cpus_read_unlock() in start_per_cpu_kthreads()

2021-09-18T11:44:05+00:00

commit 4b6b08f2e45edda4c067ac40833e3c1f84383c0b upstream. When start_kthread() return error, the cpus_read_unlock() need to be called. Link: https://lkml.kernel.org/r/20210831022919.27630-1-qiang.zhang@windriver.com Cc: Fixes: c8895e271f79 ("trace/osnoise: Support hotplug operations") Acked-by: Daniel Bristot de Oliveira Signed-off-by: Qiang.Zhang Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-08-17T19:47:18+00:00

Pull tracing fix from Steven Rostedt: "Limit the shooting in the foot of tp_printk The "tp_printk" option redirects the trace event output to printk at boot up. This is useful when a machine crashes before boot where the trace events can not be retrieved by the in kernel ring buffer. But it can be "dangerous" because trace events can be located in high frequency locations such as interrupts and the scheduler, where a printk can slow it down that it live locks the machine (because by the time the printk finishes, the next event is triggered). Thus tp_printk must be used with care. It was discovered that the filter logic to trace events does not apply to the tp_printk events. This can cause a surprise and live lock when the user expects it to be filtered to limit the amount of events printed to the console when in fact it still prints everything" * tag 'trace-v5.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Apply trace filters on all output channels

Merge tag 'trace-v5.14-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2021-08-16T16:31:06+00:00

Pull tracing fixes from Steven Rostedt: "Fixes and clean ups to tracing: - Fix header alignment when PREEMPT_RT is enabled for osnoise tracer - Inject "stop" event to see where osnoise stopped the trace - Define DYNAMIC_FTRACE_WITH_ARGS as some code had an #ifdef for it - Fix erroneous message for bootconfig cmdline parameter - Fix crash caused by not found variable in histograms" * tag 'trace-v5.14-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name init: Suppress wrong warning for bootconfig cmdline parameter tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS trace/osnoise: Print a stop tracing message trace/timerlat: Add a header with PREEMPT_RT additional fields trace/osnoise: Add a header with PREEMPT_RT additional fields

tracing: Apply trace filters on all output channels

2021-08-16T15:01:52+00:00

The event filters are not applied on all of the output, which results in the flood of printk when using tp_printk. Unfolding event_trigger_unlock_commit_regs() into trace_event_buffer_commit(), so the filters can be applied on every output. Link: https://lkml.kernel.org/r/20210814034538.8428-1-kernelfans@gmail.com Cc: stable@vger.kernel.org Fixes: 0daa2302968c1 ("tracing: Add tp_printk cmdline to have tracepoints go to printk()") Signed-off-by: Pingfan Liu Signed-off-by: Steven Rostedt (VMware)

tracing / histogram: Fix NULL pointer dereference on strcmp() on NULL event name

2021-08-12T17:35:57+00:00

The following commands: # echo 'read_max u64 size;' > synthetic_events # echo 'hist:keys=common_pid:count=count:onmax($count).trace(read_max,count)' > events/syscalls/sys_enter_read/trigger Causes: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 4 PID: 1763 Comm: bash Not tainted 5.14.0-rc2-test+ #155 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:strcmp+0xc/0x20 Code: 75 f7 31 c0 0f b6 0c 06 88 0c 02 48 83 c0 01 84 c9 75 f1 4c 89 c0 c3 0f 1f 80 00 00 00 00 31 c0 eb 08 48 83 c0 01 84 d2 74 0f <0f> b6 14 07 3a 14 06 74 ef 19 c0 83 c8 01 c3 31 c0 c3 66 90 48 89 RSP: 0018:ffffb5fdc0963ca8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffb3a4e040 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9714c0d0b640 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000022986b7cde R09: ffffffffb3a4dff8 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9714c50603c8 R13: 0000000000000000 R14: ffff97143fdf9e48 R15: ffff9714c01a2210 FS: 00007f1fa6785740(0000) GS:ffff9714da400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000002d863004 CR4: 00000000001706e0 Call Trace: __find_event_file+0x4e/0x80 action_create+0x6b7/0xeb0 ? kstrdup+0x44/0x60 event_hist_trigger_func+0x1a07/0x2130 trigger_process_regex+0xbd/0x110 event_trigger_write+0x71/0xd0 vfs_write+0xe9/0x310 ksys_write+0x68/0xe0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f1fa6879e87 The problem was the "trace(read_max,count)" where the "count" should be "$count" as "onmax()" only handles variables (although it really should be able to figure out that "count" is a field of sys_enter_read). But there's a path that does not find the variable and ends up passing a NULL for the event, which ends up getting passed to "strcmp()". Add a check for NULL to return and error on the command with: # cat error_log hist:syscalls:sys_enter_read: error: Couldn't create or find variable Command: hist:keys=common_pid:count=count:onmax($count).trace(read_max,count) ^ Link: https://lkml.kernel.org/r/20210808003011.4037f8d0@oasis.local.home Cc: Masami Hiramatsu Cc: stable@vger.kernel.org Fixes: 50450603ec9cb tracing: Add 'onmax' hist trigger action support Reviewed-by: Tom Zanussi Signed-off-by: Steven Rostedt (VMware)

tracing: define needed config DYNAMIC_FTRACE_WITH_ARGS

2021-08-12T17:35:57+00:00

Commit 2860cd8a2353 ("livepatch: Use the default ftrace_ops instead of REGS when ARGS is available") intends to enable config LIVEPATCH when ftrace with ARGS is available. However, the chain of configs to enable LIVEPATCH is incomplete, as HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, but the definition of DYNAMIC_FTRACE_WITH_ARGS, combining DYNAMIC_FTRACE and HAVE_DYNAMIC_FTRACE_WITH_ARGS, needed to enable LIVEPATCH, is missing in the commit. Fortunately, ./scripts/checkkconfigsymbols.py detects this and warns: DYNAMIC_FTRACE_WITH_ARGS Referencing files: kernel/livepatch/Kconfig So, define the config DYNAMIC_FTRACE_WITH_ARGS analogously to the already existing similar configs, DYNAMIC_FTRACE_WITH_REGS and DYNAMIC_FTRACE_WITH_DIRECT_CALLS, in ./kernel/trace/Kconfig to connect the chain of configs. Link: https://lore.kernel.org/kernel-janitors/CAKXUXMwT2zS9fgyQHKUUiqo8ynZBdx2UEUu1WnV_q0OCmknqhw@mail.gmail.com/ Link: https://lkml.kernel.org/r/20210806195027.16808-1-lukas.bulwahn@gmail.com Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Peter Zijlstra Cc: Miroslav Benes Cc: stable@vger.kernel.org Fixes: 2860cd8a2353 ("livepatch: Use the default ftrace_ops instead of REGS when ARGS is available") Signed-off-by: Lukas Bulwahn Signed-off-by: Steven Rostedt (VMware)