[for-linus][PATCH 0/7] probes: Fixes for 6.1

[for-linus][PATCH 0/7] probes: Fixes for 6.1

[Steven Rostedt]

  git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
probes/urgent

Head SHA1: 40adaf51cb318131073d1ba8233d473cc105ecbf


Li Huafei (1):
      kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case

Masami Hiramatsu (Google) (1):
      tracing/eprobe: Fix eprobe filter to make a filter correctly

Rafael Mendonca (2):
      tracing/eprobe: Fix memory leak of filter string
      tracing/eprobe: Fix warning in filter creation

Shang XiaoJing (2):
      tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()
      tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()

Yi Yang (1):
      rethook: fix a potential memleak in rethook_alloc()

----
 kernel/kprobes.c                     |  8 +++++-
 kernel/trace/kprobe_event_gen_test.c | 48 ++++++++++++++++++++++++------------
 kernel/trace/rethook.c               |  4 ++-
 kernel/trace/trace_eprobe.c          |  5 ++--
 4 files changed, 45 insertions(+), 20 deletions(-)

[for-linus][PATCH 1/7] tracing: kprobe: Fix potential null-ptr-deref on trace_event_file in kprobe_event_gen_test_exit()

[Steven Rostedt]

From: Shang XiaoJing <shangxiaojing@huawei.com>

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>
---
 kernel/trace/kprobe_event_gen_test.c | 44 ++++++++++++++++++----------
 1 file changed, 28 insertions(+), 16 deletions(-)

diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
index d81f7c51025c..1c98fafcf333 100644
--- a/kernel/trace/kprobe_event_gen_test.c
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -73,6 +73,10 @@ static struct trace_event_file *gen_kretprobe_test;
 #define KPROBE_GEN_TEST_ARG3	NULL
 #endif
 
+static bool trace_event_file_is_valid(struct trace_event_file *input)
+{
+	return input && !IS_ERR(input);
+}
 
 /*
  * Test to make sure we can create a kprobe event, then add more
@@ -217,10 +221,12 @@ static int __init kprobe_event_gen_test_init(void)
 
 	ret = test_gen_kretprobe_cmd();
 	if (ret) {
-		WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
-						  "kprobes",
-						  "gen_kretprobe_test", false));
-		trace_put_event_file(gen_kretprobe_test);
+		if (trace_event_file_is_valid(gen_kretprobe_test)) {
+			WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+							  "kprobes",
+							  "gen_kretprobe_test", false));
+			trace_put_event_file(gen_kretprobe_test);
+		}
 		WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
 	}
 
@@ -229,24 +235,30 @@ static int __init kprobe_event_gen_test_init(void)
 
 static void __exit kprobe_event_gen_test_exit(void)
 {
-	/* Disable the event or you can't remove it */
-	WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
-					  "kprobes",
-					  "gen_kprobe_test", false));
+	if (trace_event_file_is_valid(gen_kprobe_test)) {
+		/* Disable the event or you can't remove it */
+		WARN_ON(trace_array_set_clr_event(gen_kprobe_test->tr,
+						  "kprobes",
+						  "gen_kprobe_test", false));
+
+		/* Now give the file and instance back */
+		trace_put_event_file(gen_kprobe_test);
+	}
 
-	/* Now give the file and instance back */
-	trace_put_event_file(gen_kprobe_test);
 
 	/* Now unregister and free the event */
 	WARN_ON(kprobe_event_delete("gen_kprobe_test"));
 
-	/* Disable the event or you can't remove it */
-	WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
-					  "kprobes",
-					  "gen_kretprobe_test", false));
+	if (trace_event_file_is_valid(gen_kretprobe_test)) {
+		/* Disable the event or you can't remove it */
+		WARN_ON(trace_array_set_clr_event(gen_kretprobe_test->tr,
+						  "kprobes",
+						  "gen_kretprobe_test", false));
+
+		/* Now give the file and instance back */
+		trace_put_event_file(gen_kretprobe_test);
+	}
 
-	/* Now give the file and instance back */
-	trace_put_event_file(gen_kretprobe_test);
 
 	/* Now unregister and free the event */
 	WARN_ON(kprobe_event_delete("gen_kretprobe_test"));
-- 
2.35.1

[for-linus][PATCH 2/7] tracing: kprobe: Fix potential null-ptr-deref on trace_array in kprobe_event_gen_test_exit()

[Steven Rostedt]

From: Shang XiaoJing <shangxiaojing@huawei.com>

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>
---
 kernel/trace/kprobe_event_gen_test.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
index 1c98fafcf333..c736487fc0e4 100644
--- a/kernel/trace/kprobe_event_gen_test.c
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -143,6 +143,8 @@ static int __init test_gen_kprobe_cmd(void)
 	kfree(buf);
 	return ret;
  delete:
+	if (trace_event_file_is_valid(gen_kprobe_test))
+		gen_kprobe_test = NULL;
 	/* We got an error after creating the event, delete it */
 	ret = kprobe_event_delete("gen_kprobe_test");
 	goto out;
@@ -206,6 +208,8 @@ static int __init test_gen_kretprobe_cmd(void)
 	kfree(buf);
 	return ret;
  delete:
+	if (trace_event_file_is_valid(gen_kretprobe_test))
+		gen_kretprobe_test = NULL;
 	/* We got an error after creating the event, delete it */
 	ret = kprobe_event_delete("gen_kretprobe_test");
 	goto out;
-- 
2.35.1

[for-linus][PATCH 3/7] tracing/eprobe: Fix memory leak of filter string

[Steven Rostedt]

From: Rafael Mendonca <rafaelmendsr@gmail.com>

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>
---
 kernel/trace/trace_eprobe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 5dd0617e5df6..fe4833a7b7b3 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -52,6 +52,7 @@ static void trace_event_probe_cleanup(struct trace_eprobe *ep)
 	kfree(ep->event_system);
 	if (ep->event)
 		trace_event_put_ref(ep->event);
+	kfree(ep->filter_str);
 	kfree(ep);
 }
 
-- 
2.35.1

[for-linus][PATCH 4/7] rethook: fix a potential memleak in rethook_alloc()

[Steven Rostedt]

From: Yi Yang <yiyang13@huawei.com>

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>
---
 kernel/trace/rethook.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c
index c69d82273ce7..32c3dfdb4d6a 100644
--- a/kernel/trace/rethook.c
+++ b/kernel/trace/rethook.c
@@ -83,8 +83,10 @@ struct rethook *rethook_alloc(void *data, rethook_handler_t handler)
 {
 	struct rethook *rh = kzalloc(sizeof(struct rethook), GFP_KERNEL);
 
-	if (!rh || !handler)
+	if (!rh || !handler) {
+		kfree(rh);
 		return NULL;
+	}
 
 	rh->data = data;
 	rh->handler = handler;
-- 
2.35.1

[for-linus][PATCH 5/7] kprobes: Skip clearing aggrprobes post_handler in kprobe-on-ftrace case

[Steven Rostedt]

From: Li Huafei <lihuafei1@huawei.com>

In __unregister_kprobe_top(), if the currently unregistered probe has
post_handler but other child probes of the aggrprobe do not have
post_handler, the post_handler of the aggrprobe is cleared. If this is
a ftrace-based probe, there is a problem. In later calls to
disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is
NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in
__disarm_kprobe_ftrace() and may even cause use-after-free:

  Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)
  WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0
  Modules linked in: testKprobe_007(-)
  CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18
  [...]
  Call Trace:
   <TASK>
   __disable_kprobe+0xcd/0xe0
   __unregister_kprobe_top+0x12/0x150
   ? mutex_lock+0xe/0x30
   unregister_kprobes.part.23+0x31/0xa0
   unregister_kprobe+0x32/0x40
   __x64_sys_delete_module+0x15e/0x260
   ? do_user_addr_fault+0x2cd/0x6b0
   do_syscall_64+0x3a/0x90
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
   [...]

For the kprobe-on-ftrace case, we keep the post_handler setting to
identify this aggrprobe armed with kprobe_ipmodify_ops. This way we
can disarm it correctly.

Link: https://lore.kernel.org/all/20221112070000.35299-1-lihuafei1@huawei.com/

Fixes: 0bc11ed5ab60 ("kprobes: Allow kprobes coexist with livepatch")
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 kernel/kprobes.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index cd9f5a66a690..3050631e528d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1766,7 +1766,13 @@ static int __unregister_kprobe_top(struct kprobe *p)
 				if ((list_p != p) && (list_p->post_handler))
 					goto noclean;
 			}
-			ap->post_handler = NULL;
+			/*
+			 * For the kprobe-on-ftrace case, we keep the
+			 * post_handler setting to identify this aggrprobe
+			 * armed with kprobe_ipmodify_ops.
+			 */
+			if (!kprobe_ftrace(ap))
+				ap->post_handler = NULL;
 		}
 noclean:
 		/*
-- 
2.35.1

[for-linus][PATCH 6/7] tracing/eprobe: Fix warning in filter creation

[Steven Rostedt]

From: Rafael Mendonca <rafaelmendsr@gmail.com>

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>
---
 kernel/trace/trace_eprobe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index fe4833a7b7b3..e888446d80fa 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -901,7 +901,7 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[
 
 static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const char *argv[])
 {
-	struct event_filter *dummy;
+	struct event_filter *dummy = NULL;
 	int i, ret, len = 0;
 	char *p;
 
-- 
2.35.1

[for-linus][PATCH 7/7] tracing/eprobe: Fix eprobe filter to make a filter correctly

[Steven Rostedt]

From: "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>
---
 kernel/trace/trace_eprobe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index e888446d80fa..123d2c0a6b68 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -643,7 +643,7 @@ new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
 	INIT_LIST_HEAD(&trigger->list);
 
 	if (ep->filter_str) {
-		ret = create_event_filter(file->tr, file->event_call,
+		ret = create_event_filter(file->tr, ep->event,
 					ep->filter_str, false, &filter);
 		if (ret)
 			goto error;
-- 
2.35.1