linux.git/kernel/trace, branch v6.1-rc7 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git Merge tag 'trace-probes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2022-11-20T23:31:20+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-11-20T23:31:20+00:00 c6c67bf9bc2714d9c2c2e7ecfbf29d912b8c4f17 Pull tracing/probes fixes from Steven Rostedt: - Fix possible NULL pointer dereference on trace_event_file in kprobe_event_gen_test_exit() - Fix NULL pointer dereference for trace_array in kprobe_event_gen_test_exit() - Fix memory leak of filter string for eprobes - Fix a possible memory leak in rethook_alloc() - Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case which can cause a possible use-after-free - Fix warning in eprobe filter creation - Fix eprobe filter creation as it picked the wrong event for the fields * tag 'trace-probes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/eprobe: Fix eprobe filter to make a filter correctly tracing/eprobe: Fix warning in filter creation kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case rethook: fix a potential memleak in rethook_alloc() tracing/eprobe: Fix memory leak of filter string tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit() tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit() 
Pull tracing/probes fixes from Steven Rostedt:

 - Fix possible NULL pointer dereference on trace_event_file in
   kprobe_event_gen_test_exit()

 - Fix NULL pointer dereference for trace_array in
   kprobe_event_gen_test_exit()

 - Fix memory leak of filter string for eprobes

 - Fix a possible memory leak in rethook_alloc()

 - Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case which
   can cause a possible use-after-free

 - Fix warning in eprobe filter creation

 - Fix eprobe filter creation as it picked the wrong event for the
   fields

* tag 'trace-probes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/eprobe: Fix eprobe filter to make a filter correctly
  tracing/eprobe: Fix warning in filter creation
  kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case
  rethook: fix a potential memleak in rethook_alloc()
  tracing/eprobe: Fix memory leak of filter string
  tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()
  tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()
tracing: Fix race where eprobes can be called before the event 2022-11-20T19:05:50+00:00 Steven Rostedt (Google) rostedt@goodmis.org 2022-11-18T02:42:49+00:00 94eedf3dded5fb472ce97bfaf3ac1c6c29c35d26 The flag that tells the event to call its triggers after reading the event is set for eprobes after the eprobe is enabled. This leads to a race where the eprobe may be triggered at the beginning of the event where the record information is NULL. The eprobe then dereferences the NULL record causing a NULL kernel pointer bug. Test for a NULL record to keep this from happening. Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20221117214249.2addbe10@gandalf.local.home Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org> Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Tom Zanussi <zanussi@kernel.org> Cc: stable@vger.kernel.org Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
The flag that tells the event to call its triggers after reading the event
is set for eprobes after the eprobe is enabled. This leads to a race where
the eprobe may be triggered at the beginning of the event where the record
information is NULL. The eprobe then dereferences the NULL record causing
a NULL kernel pointer bug.

Test for a NULL record to keep this from happening.

Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20221117214249.2addbe10@gandalf.local.home

Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
tracing: Fix potential null-pointer-access of entry in list 'tr->err_log' 2022-11-18T01:41:01+00:00 Zheng Yejian zhengyejian1@huawei.com 2022-11-14T10:46:32+00:00 067df9e0ad48a97382ab2179bbe773a13a846028 Entries in list 'tr->err_log' will be reused after entry number exceed TRACING_LOG_ERRS_MAX. The cmd string of the to be reused entry will be freed first then allocated a new one. If the allocation failed, then the entry will still be in list 'tr->err_log' but its 'cmd' field is set to be NULL, later access of 'cmd' is risky. Currently above problem can cause the loss of 'cmd' information of first entry in 'tr->err_log'. When execute `cat /sys/kernel/tracing/error_log`, reproduce logs like: [ 37.495100] trace_kprobe: error: Maxactive is not for kprobe(null) ^ [ 38.412517] trace_kprobe: error: Maxactive is not for kprobe Command: p4:myprobe2 do_sys_openat2 ^ Link: https://lore.kernel.org/linux-trace-kernel/20221114104632.3547266-1-zhengyejian1@huawei.com Fixes: 1581a884b7ca ("tracing: Remove size restriction on tracing_log_err cmd strings") Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
Entries in list 'tr->err_log' will be reused after entry number
exceed TRACING_LOG_ERRS_MAX.

The cmd string of the to be reused entry will be freed first then
allocated a new one. If the allocation failed, then the entry will
still be in list 'tr->err_log' but its 'cmd' field is set to be NULL,
later access of 'cmd' is risky.

Currently above problem can cause the loss of 'cmd' information of first
entry in 'tr->err_log'. When execute `cat /sys/kernel/tracing/error_log`,
reproduce logs like:
  [   37.495100] trace_kprobe: error: Maxactive is not for kprobe(null) ^
  [   38.412517] trace_kprobe: error: Maxactive is not for kprobe
    Command: p4:myprobe2 do_sys_openat2
            ^

Link: https://lore.kernel.org/linux-trace-kernel/20221114104632.3547266-1-zhengyejian1@huawei.com

Fixes: 1581a884b7ca ("tracing: Remove size restriction on tracing_log_err cmd strings")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
tracing: Remove unused __bad_type_size() method 2022-11-18T01:21:06+00:00 Qiujun Huang hqjagain@gmail.com 2022-11-17T16:44:35+00:00 b8752064e30697e3982418f4274cc63cfc6f3027 __bad_type_size() is unused after commit 04ae87a52074("ftrace: Rework event_create_dir()"). So, remove it. Link: https://lkml.kernel.org/r/D062EC2E-7DB7-4402-A67E-33C3577F551E@gmail.com Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> 
__bad_type_size() is unused after
commit 04ae87a52074("ftrace: Rework event_create_dir()").
So, remove it.

Link: https://lkml.kernel.org/r/D062EC2E-7DB7-4402-A67E-33C3577F551E@gmail.com

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
tracing/eprobe: Fix eprobe filter to make a filter correctly 2022-11-18T01:15:34+00:00 Masami Hiramatsu (Google) mhiramat@kernel.org 2022-11-18T01:15:34+00:00 40adaf51cb318131073d1ba8233d473cc105ecbf Since the eprobe filter was defined based on the eprobe's trace event itself, it doesn't work correctly. Use the original trace event of the eprobe when making the filter so that the filter works correctly. Without this fix: # echo 'e syscalls/sys_enter_openat \ flags_rename=$flags:u32 if flags < 1000' >> dynamic_events # echo 1 > events/eprobes/sys_enter_openat/enable [ 114.551550] event trace: Could not enable event sys_enter_openat -bash: echo: write error: Invalid argument With this fix: # echo 'e syscalls/sys_enter_openat \ flags_rename=$flags:u32 if flags < 1000' >> dynamic_events # echo 1 > events/eprobes/sys_enter_openat/enable # tail trace cat-241 [000] ...1. 266.498449: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0 cat-242 [000] ...1. 266.977640: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0 Link: https://lore.kernel.org/all/166823166395.1385292.8931770640212414483.stgit@devnote3/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com> Tested-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
Since the eprobe filter was defined based on the eprobe's trace event
itself, it doesn't work correctly. Use the original trace event of
the eprobe when making the filter so that the filter works correctly.

Without this fix:

 # echo 'e syscalls/sys_enter_openat \
	flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
 # echo 1 > events/eprobes/sys_enter_openat/enable
[  114.551550] event trace: Could not enable event sys_enter_openat
-bash: echo: write error: Invalid argument

With this fix:
 # echo 'e syscalls/sys_enter_openat \
	flags_rename=$flags:u32 if flags < 1000' >> dynamic_events
 # echo 1 > events/eprobes/sys_enter_openat/enable
 # tail trace
cat-241     [000] ...1.   266.498449: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0
cat-242     [000] ...1.   266.977640: sys_enter_openat: (syscalls.sys_enter_openat) flags_rename=0

Link: https://lore.kernel.org/all/166823166395.1385292.8931770640212414483.stgit@devnote3/

Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Tested-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
tracing/eprobe: Fix warning in filter creation 2022-11-18T01:15:34+00:00 Rafael Mendonca rafaelmendsr@gmail.com 2022-11-18T01:15:34+00:00 342a4a2f99431ee3c72ef5cfff6449ccf2abd346 The filter pointer (filterp) passed to create_filter() function must be a pointer that references a NULL pointer, otherwise, we get a warning when adding a filter option to the event probe: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \ runtime=$runtime:u32 if cpu < 4' >> dynamic_events [ 5034.340439] ------------[ cut here ]------------ [ 5034.341258] WARNING: CPU: 0 PID: 223 at kernel/trace/trace_events_filter.c:1939 create_filter+0x1db/0x250 [...] stripped [ 5034.345518] RIP: 0010:create_filter+0x1db/0x250 [...] stripped [ 5034.351604] Call Trace: [ 5034.351803] <TASK> [ 5034.351959] ? process_preds+0x1b40/0x1b40 [ 5034.352241] ? rcu_read_lock_bh_held+0xd0/0xd0 [ 5034.352604] ? kasan_set_track+0x29/0x40 [ 5034.352904] ? kasan_save_alloc_info+0x1f/0x30 [ 5034.353264] create_event_filter+0x38/0x50 [ 5034.353573] __trace_eprobe_create+0x16f4/0x1d20 [ 5034.353964] ? eprobe_dyn_event_release+0x360/0x360 [ 5034.354363] ? mark_held_locks+0xa6/0xf0 [ 5034.354684] ? _raw_spin_unlock_irqrestore+0x35/0x60 [ 5034.355105] ? trace_hardirqs_on+0x41/0x120 [ 5034.355417] ? _raw_spin_unlock_irqrestore+0x35/0x60 [ 5034.355751] ? __create_object+0x5b7/0xcf0 [ 5034.356027] ? lock_is_held_type+0xaf/0x120 [ 5034.356362] ? rcu_read_lock_bh_held+0xb0/0xd0 [ 5034.356716] ? rcu_read_lock_bh_held+0xd0/0xd0 [ 5034.357084] ? kasan_set_track+0x29/0x40 [ 5034.357411] ? kasan_save_alloc_info+0x1f/0x30 [ 5034.357715] ? __kasan_kmalloc+0xb8/0xc0 [ 5034.357985] ? write_comp_data+0x2f/0x90 [ 5034.358302] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.358691] ? argv_split+0x381/0x460 [ 5034.358949] ? write_comp_data+0x2f/0x90 [ 5034.359240] ? eprobe_dyn_event_release+0x360/0x360 [ 5034.359620] trace_probe_create+0xf6/0x110 [ 5034.359940] ? trace_probe_match_command_args+0x240/0x240 [ 5034.360376] eprobe_dyn_event_create+0x21/0x30 [ 5034.360709] create_dyn_event+0xf3/0x1a0 [ 5034.360983] trace_parse_run_command+0x1a9/0x2e0 [ 5034.361297] ? dyn_event_release+0x500/0x500 [ 5034.361591] dyn_event_write+0x39/0x50 [ 5034.361851] vfs_write+0x311/0xe50 [ 5034.362091] ? dyn_event_seq_next+0x40/0x40 [ 5034.362376] ? kernel_write+0x5b0/0x5b0 [ 5034.362637] ? write_comp_data+0x2f/0x90 [ 5034.362937] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.363258] ? ftrace_syscall_enter+0x544/0x840 [ 5034.363563] ? write_comp_data+0x2f/0x90 [ 5034.363837] ? __sanitizer_cov_trace_pc+0x25/0x60 [ 5034.364156] ? write_comp_data+0x2f/0x90 [ 5034.364468] ? write_comp_data+0x2f/0x90 [ 5034.364770] ksys_write+0x158/0x2a0 [ 5034.365022] ? __ia32_sys_read+0xc0/0xc0 [ 5034.365344] __x64_sys_write+0x7c/0xc0 [ 5034.365669] ? syscall_enter_from_user_mode+0x53/0x70 [ 5034.366084] do_syscall_64+0x60/0x90 [ 5034.366356] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 5034.366767] RIP: 0033:0x7ff0b43938f3 [...] stripped [ 5034.371892] </TASK> [ 5034.374720] ---[ end trace 0000000000000000 ]--- Link: https://lore.kernel.org/all/20221108202148.1020111-1-rafaelmendsr@gmail.com/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
The filter pointer (filterp) passed to create_filter() function must be a
pointer that references a NULL pointer, otherwise, we get a warning when
adding a filter option to the event probe:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \
        runtime=$runtime:u32 if cpu < 4' >> dynamic_events
[ 5034.340439] ------------[ cut here ]------------
[ 5034.341258] WARNING: CPU: 0 PID: 223 at kernel/trace/trace_events_filter.c:1939 create_filter+0x1db/0x250
[...] stripped
[ 5034.345518] RIP: 0010:create_filter+0x1db/0x250
[...] stripped
[ 5034.351604] Call Trace:
[ 5034.351803]  <TASK>
[ 5034.351959]  ? process_preds+0x1b40/0x1b40
[ 5034.352241]  ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.352604]  ? kasan_set_track+0x29/0x40
[ 5034.352904]  ? kasan_save_alloc_info+0x1f/0x30
[ 5034.353264]  create_event_filter+0x38/0x50
[ 5034.353573]  __trace_eprobe_create+0x16f4/0x1d20
[ 5034.353964]  ? eprobe_dyn_event_release+0x360/0x360
[ 5034.354363]  ? mark_held_locks+0xa6/0xf0
[ 5034.354684]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355105]  ? trace_hardirqs_on+0x41/0x120
[ 5034.355417]  ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355751]  ? __create_object+0x5b7/0xcf0
[ 5034.356027]  ? lock_is_held_type+0xaf/0x120
[ 5034.356362]  ? rcu_read_lock_bh_held+0xb0/0xd0
[ 5034.356716]  ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.357084]  ? kasan_set_track+0x29/0x40
[ 5034.357411]  ? kasan_save_alloc_info+0x1f/0x30
[ 5034.357715]  ? __kasan_kmalloc+0xb8/0xc0
[ 5034.357985]  ? write_comp_data+0x2f/0x90
[ 5034.358302]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.358691]  ? argv_split+0x381/0x460
[ 5034.358949]  ? write_comp_data+0x2f/0x90
[ 5034.359240]  ? eprobe_dyn_event_release+0x360/0x360
[ 5034.359620]  trace_probe_create+0xf6/0x110
[ 5034.359940]  ? trace_probe_match_command_args+0x240/0x240
[ 5034.360376]  eprobe_dyn_event_create+0x21/0x30
[ 5034.360709]  create_dyn_event+0xf3/0x1a0
[ 5034.360983]  trace_parse_run_command+0x1a9/0x2e0
[ 5034.361297]  ? dyn_event_release+0x500/0x500
[ 5034.361591]  dyn_event_write+0x39/0x50
[ 5034.361851]  vfs_write+0x311/0xe50
[ 5034.362091]  ? dyn_event_seq_next+0x40/0x40
[ 5034.362376]  ? kernel_write+0x5b0/0x5b0
[ 5034.362637]  ? write_comp_data+0x2f/0x90
[ 5034.362937]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.363258]  ? ftrace_syscall_enter+0x544/0x840
[ 5034.363563]  ? write_comp_data+0x2f/0x90
[ 5034.363837]  ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.364156]  ? write_comp_data+0x2f/0x90
[ 5034.364468]  ? write_comp_data+0x2f/0x90
[ 5034.364770]  ksys_write+0x158/0x2a0
[ 5034.365022]  ? __ia32_sys_read+0xc0/0xc0
[ 5034.365344]  __x64_sys_write+0x7c/0xc0
[ 5034.365669]  ? syscall_enter_from_user_mode+0x53/0x70
[ 5034.366084]  do_syscall_64+0x60/0x90
[ 5034.366356]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 5034.366767] RIP: 0033:0x7ff0b43938f3
[...] stripped
[ 5034.371892]  </TASK>
[ 5034.374720] ---[ end trace 0000000000000000 ]---

Link: https://lore.kernel.org/all/20221108202148.1020111-1-rafaelmendsr@gmail.com/

Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
rethook: fix a potential memleak in rethook_alloc() 2022-11-18T01:15:34+00:00 Yi Yang yiyang13@huawei.com 2022-11-18T01:15:34+00:00 0a1ebe35cb3b7aa1f4b26b37e2a0b9ae68dc4ffb In rethook_alloc(), the variable rh is not freed or passed out if handler is NULL, which could lead to a memleak, fix it. Link: https://lore.kernel.org/all/20221110104438.88099-1-yiyang13@huawei.com/ [Masami: Add "rethook:" tag to the title.] Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook") Cc: stable@vger.kernel.org Signed-off-by: Yi Yang <yiyang13@huawei.com> Acke-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
In rethook_alloc(), the variable rh is not freed or passed out
if handler is NULL, which could lead to a memleak, fix it.

Link: https://lore.kernel.org/all/20221110104438.88099-1-yiyang13@huawei.com/
[Masami: Add "rethook:" tag to the title.]

Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook")
Cc: stable@vger.kernel.org
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Acke-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
tracing/eprobe: Fix memory leak of filter string 2022-11-18T01:15:34+00:00 Rafael Mendonca rafaelmendsr@gmail.com 2022-11-18T01:15:34+00:00 d1776c0202aac8251e6b4cbe096ad2950ed6c506 The filter string doesn't get freed when a dynamic event is deleted. If a filter is set, then memory is leaked: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events root@localhost:/sys/kernel/tracing# echo "-:egroup/stat_runtime_4core" >> dynamic_events root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak [ 224.416373] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88810156f1b8 (size 8): comm "bash", pid 224, jiffies 4294935612 (age 55.800s) hex dump (first 8 bytes): 63 70 75 20 3c 20 34 00 cpu < 4. backtrace: [<000000009f880725>] __kmem_cache_alloc_node+0x18e/0x720 [<0000000042492946>] __kmalloc+0x57/0x240 [<0000000034ea7995>] __trace_eprobe_create+0x1214/0x1d30 [<00000000d70ef730>] trace_probe_create+0xf6/0x110 [<00000000915c7b16>] eprobe_dyn_event_create+0x21/0x30 [<000000000d894386>] create_dyn_event+0xf3/0x1a0 [<00000000e9af57d5>] trace_parse_run_command+0x1a9/0x2e0 [<0000000080777f18>] dyn_event_write+0x39/0x50 [<0000000089f0ec73>] vfs_write+0x311/0xe50 [<000000003da1bdda>] ksys_write+0x158/0x2a0 [<00000000bb1e616e>] __x64_sys_write+0x7c/0xc0 [<00000000e8aef1f7>] do_syscall_64+0x60/0x90 [<00000000fe7fe8ba>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Additionally, in __trace_eprobe_create() function, if an error occurs after the call to trace_eprobe_parse_filter(), which allocates the filter string, then memory is also leaked. That can be reproduced by creating the same event probe twice: root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \ sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events -bash: echo: write error: File exists root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak [ 207.871584] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak) root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8881020d17a8 (size 8): comm "bash", pid 223, jiffies 4294938308 (age 31.000s) hex dump (first 8 bytes): 63 70 75 20 3c 20 34 00 cpu < 4. backtrace: [<000000000e4f5f31>] __kmem_cache_alloc_node+0x18e/0x720 [<0000000024f0534b>] __kmalloc+0x57/0x240 [<000000002930a28e>] __trace_eprobe_create+0x1214/0x1d30 [<0000000028387903>] trace_probe_create+0xf6/0x110 [<00000000a80d6a9f>] eprobe_dyn_event_create+0x21/0x30 [<000000007168698c>] create_dyn_event+0xf3/0x1a0 [<00000000f036bf6a>] trace_parse_run_command+0x1a9/0x2e0 [<00000000014bde8b>] dyn_event_write+0x39/0x50 [<0000000078a097f7>] vfs_write+0x311/0xe50 [<00000000996cb208>] ksys_write+0x158/0x2a0 [<00000000a3c2acb0>] __x64_sys_write+0x7c/0xc0 [<0000000006b5d698>] do_syscall_64+0x60/0x90 [<00000000780e8ecf>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fix both issues by releasing the filter string in trace_event_probe_cleanup(). Link: https://lore.kernel.org/all/20221108235738.1021467-1-rafaelmendsr@gmail.com/ Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
The filter string doesn't get freed when a dynamic event is deleted. If a
filter is set, then memory is leaked:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
root@localhost:/sys/kernel/tracing# echo "-:egroup/stat_runtime_4core"  >> dynamic_events
root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak
[  224.416373] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88810156f1b8 (size 8):
  comm "bash", pid 224, jiffies 4294935612 (age 55.800s)
  hex dump (first 8 bytes):
    63 70 75 20 3c 20 34 00                          cpu < 4.
  backtrace:
    [<000000009f880725>] __kmem_cache_alloc_node+0x18e/0x720
    [<0000000042492946>] __kmalloc+0x57/0x240
    [<0000000034ea7995>] __trace_eprobe_create+0x1214/0x1d30
    [<00000000d70ef730>] trace_probe_create+0xf6/0x110
    [<00000000915c7b16>] eprobe_dyn_event_create+0x21/0x30
    [<000000000d894386>] create_dyn_event+0xf3/0x1a0
    [<00000000e9af57d5>] trace_parse_run_command+0x1a9/0x2e0
    [<0000000080777f18>] dyn_event_write+0x39/0x50
    [<0000000089f0ec73>] vfs_write+0x311/0xe50
    [<000000003da1bdda>] ksys_write+0x158/0x2a0
    [<00000000bb1e616e>] __x64_sys_write+0x7c/0xc0
    [<00000000e8aef1f7>] do_syscall_64+0x60/0x90
    [<00000000fe7fe8ba>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Additionally, in __trace_eprobe_create() function, if an error occurs after
the call to trace_eprobe_parse_filter(), which allocates the filter string,
then memory is also leaked. That can be reproduced by creating the same
event probe twice:

root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core \
        sched/sched_stat_runtime runtime=$runtime:u32 if cpu < 4' >> dynamic_events
-bash: echo: write error: File exists
root@localhost:/sys/kernel/tracing# echo scan > /sys/kernel/debug/kmemleak
[  207.871584] kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
root@localhost:/sys/kernel/tracing# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8881020d17a8 (size 8):
  comm "bash", pid 223, jiffies 4294938308 (age 31.000s)
  hex dump (first 8 bytes):
    63 70 75 20 3c 20 34 00                          cpu < 4.
  backtrace:
    [<000000000e4f5f31>] __kmem_cache_alloc_node+0x18e/0x720
    [<0000000024f0534b>] __kmalloc+0x57/0x240
    [<000000002930a28e>] __trace_eprobe_create+0x1214/0x1d30
    [<0000000028387903>] trace_probe_create+0xf6/0x110
    [<00000000a80d6a9f>] eprobe_dyn_event_create+0x21/0x30
    [<000000007168698c>] create_dyn_event+0xf3/0x1a0
    [<00000000f036bf6a>] trace_parse_run_command+0x1a9/0x2e0
    [<00000000014bde8b>] dyn_event_write+0x39/0x50
    [<0000000078a097f7>] vfs_write+0x311/0xe50
    [<00000000996cb208>] ksys_write+0x158/0x2a0
    [<00000000a3c2acb0>] __x64_sys_write+0x7c/0xc0
    [<0000000006b5d698>] do_syscall_64+0x60/0x90
    [<00000000780e8ecf>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fix both issues by releasing the filter string in
trace_event_probe_cleanup().

Link: https://lore.kernel.org/all/20221108235738.1021467-1-rafaelmendsr@gmail.com/

Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit() 2022-11-18T01:15:34+00:00 Shang XiaoJing shangxiaojing@huawei.com 2022-11-18T01:15:34+00:00 22ea4ca9631eb137e64e5ab899e9c89cb6670959 When test_gen_kprobe_cmd() failed after kprobe_event_gen_cmd_end(), it will goto delete, which will call kprobe_event_delete() and release the corresponding resource. However, the trace_array in gen_kretprobe_test will point to the invalid resource. Set gen_kretprobe_test to NULL after called kprobe_event_delete() to prevent null-ptr-deref. BUG: kernel NULL pointer dereference, address: 0000000000000070 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 246 Comm: modprobe Tainted: G W 6.1.0-rc1-00174-g9522dc5c87da-dirty #248 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:__ftrace_set_clr_event_nolock+0x53/0x1b0 Code: e8 82 26 fc ff 49 8b 1e c7 44 24 0c ea ff ff ff 49 39 de 0f 84 3c 01 00 00 c7 44 24 18 00 00 00 00 e8 61 26 fc ff 48 8b 6b 10 <44> 8b 65 70 4c 8b 6d 18 41 f7 c4 00 02 00 00 75 2f RSP: 0018:ffffc9000159fe00 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88810971d268 RCX: 0000000000000000 RDX: ffff8881080be600 RSI: ffffffff811b48ff RDI: ffff88810971d058 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffc9000159fe58 R11: 0000000000000001 R12: ffffffffa0001064 R13: ffffffffa000106c R14: ffff88810971d238 R15: 0000000000000000 FS: 00007f89eeff6540(0000) GS:ffff88813b600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000070 CR3: 000000010599e004 CR4: 0000000000330ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __ftrace_set_clr_event+0x3e/0x60 trace_array_set_clr_event+0x35/0x50 ? 0xffffffffa0000000 kprobe_event_gen_test_exit+0xcd/0x10b [kprobe_event_gen_test] __x64_sys_delete_module+0x206/0x380 ? lockdep_hardirqs_on_prepare+0xd8/0x190 ? syscall_enter_from_user_mode+0x1c/0x50 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f89eeb061b7 Link: https://lore.kernel.org/all/20221108015130.28326-3-shangxiaojing@huawei.com/ Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
When test_gen_kprobe_cmd() failed after kprobe_event_gen_cmd_end(), it
will goto delete, which will call kprobe_event_delete() and release the
corresponding resource. However, the trace_array in gen_kretprobe_test
will point to the invalid resource. Set gen_kretprobe_test to NULL
after called kprobe_event_delete() to prevent null-ptr-deref.

BUG: kernel NULL pointer dereference, address: 0000000000000070
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 246 Comm: modprobe Tainted: G        W
6.1.0-rc1-00174-g9522dc5c87da-dirty #248
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:__ftrace_set_clr_event_nolock+0x53/0x1b0
Code: e8 82 26 fc ff 49 8b 1e c7 44 24 0c ea ff ff ff 49 39 de 0f 84 3c
01 00 00 c7 44 24 18 00 00 00 00 e8 61 26 fc ff 48 8b 6b 10 <44> 8b 65
70 4c 8b 6d 18 41 f7 c4 00 02 00 00 75 2f
RSP: 0018:ffffc9000159fe00 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88810971d268 RCX: 0000000000000000
RDX: ffff8881080be600 RSI: ffffffff811b48ff RDI: ffff88810971d058
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffc9000159fe58 R11: 0000000000000001 R12: ffffffffa0001064
R13: ffffffffa000106c R14: ffff88810971d238 R15: 0000000000000000
FS:  00007f89eeff6540(0000) GS:ffff88813b600000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000070 CR3: 000000010599e004 CR4: 0000000000330ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __ftrace_set_clr_event+0x3e/0x60
 trace_array_set_clr_event+0x35/0x50
 ? 0xffffffffa0000000
 kprobe_event_gen_test_exit+0xcd/0x10b [kprobe_event_gen_test]
 __x64_sys_delete_module+0x206/0x380
 ? lockdep_hardirqs_on_prepare+0xd8/0x190
 ? syscall_enter_from_user_mode+0x1c/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f89eeb061b7

Link: https://lore.kernel.org/all/20221108015130.28326-3-shangxiaojing@huawei.com/

Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit() 2022-11-18T01:15:33+00:00 Shang XiaoJing shangxiaojing@huawei.com 2022-11-18T01:15:33+00:00 e0d75267f59d7084e0468bd68beeb1bf9c71d7c0 When trace_get_event_file() failed, gen_kretprobe_test will be assigned as the error code. If module kprobe_event_gen_test is removed now, the null pointer dereference will happen in kprobe_event_gen_test_exit(). Check if gen_kprobe_test or gen_kretprobe_test is error code or NULL before dereference them. BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 3 PID: 2210 Comm: modprobe Not tainted 6.1.0-rc1-00171-g2159299a3b74-dirty #217 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:kprobe_event_gen_test_exit+0x1c/0xb5 [kprobe_event_gen_test] Code: Unable to access opcode bytes at 0xffffffff9ffffff2. RSP: 0018:ffffc900015bfeb8 EFLAGS: 00010246 RAX: ffffffffffffffea RBX: ffffffffa0002080 RCX: 0000000000000000 RDX: ffffffffa0001054 RSI: ffffffffa0001064 RDI: ffffffffdfc6349c RBP: ffffffffa0000000 R08: 0000000000000004 R09: 00000000001e95c0 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000800 R13: ffffffffa0002420 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f56b75be540(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff9ffffff2 CR3: 000000010874a006 CR4: 0000000000330ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __x64_sys_delete_module+0x206/0x380 ? lockdep_hardirqs_on_prepare+0xd8/0x190 ? syscall_enter_from_user_mode+0x1c/0x50 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Link: https://lore.kernel.org/all/20221108015130.28326-2-shangxiaojing@huawei.com/ Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> 
When trace_get_event_file() failed, gen_kretprobe_test will be assigned
as the error code. If module kprobe_event_gen_test is removed now, the
null pointer dereference will happen in kprobe_event_gen_test_exit().
Check if gen_kprobe_test or gen_kretprobe_test is error code or NULL
before dereference them.

BUG: kernel NULL pointer dereference, address: 0000000000000012
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 3 PID: 2210 Comm: modprobe Not tainted
6.1.0-rc1-00171-g2159299a3b74-dirty #217
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:kprobe_event_gen_test_exit+0x1c/0xb5 [kprobe_event_gen_test]
Code: Unable to access opcode bytes at 0xffffffff9ffffff2.
RSP: 0018:ffffc900015bfeb8 EFLAGS: 00010246
RAX: ffffffffffffffea RBX: ffffffffa0002080 RCX: 0000000000000000
RDX: ffffffffa0001054 RSI: ffffffffa0001064 RDI: ffffffffdfc6349c
RBP: ffffffffa0000000 R08: 0000000000000004 R09: 00000000001e95c0
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000800
R13: ffffffffa0002420 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f56b75be540(0000) GS:ffff88813bc00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff9ffffff2 CR3: 000000010874a006 CR4: 0000000000330ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __x64_sys_delete_module+0x206/0x380
 ? lockdep_hardirqs_on_prepare+0xd8/0x190
 ? syscall_enter_from_user_mode+0x1c/0x50
 do_syscall_64+0x3f/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Link: https://lore.kernel.org/all/20221108015130.28326-2-shangxiaojing@huawei.com/

Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>