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
Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
Signed-off-by: Shang XiaoJing <[email protected]>
Cc: [email protected]
---
changes in v2:
- add cc tag to [email protected].
- set gen_kprobe_test to NULL instead of gen_kprobe_test->tr, so as
gen_kretprobe_test.
---
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;
--
2.17.1
On Tue, 8 Nov 2022 09:51:30 +0800
Shang XiaoJing <[email protected]> wrote:
> 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
>
> Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
> Signed-off-by: Shang XiaoJing <[email protected]>
This looks good to me.
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Thank you!
> Cc: [email protected]
> ---
> changes in v2:
> - add cc tag to [email protected].
> - set gen_kprobe_test to NULL instead of gen_kprobe_test->tr, so as
> gen_kretprobe_test.
> ---
> 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;
> --
> 2.17.1
>
--
Masami Hiramatsu (Google) <[email protected]>
On Tue, 8 Nov 2022 23:38:46 +0900
Masami Hiramatsu (Google) <[email protected]> wrote:
> > Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
> > Signed-off-by: Shang XiaoJing <[email protected]>
>
> This looks good to me.
>
> Acked-by: Masami Hiramatsu (Google) <[email protected]>
Hi Masami,
Did you want me to pull these on top of your probes/urgent branch?
I'm going through all my patches now and will be starting the testing
hopefully later this week.
-- Steve
On Wed, 16 Nov 2022 21:55:36 -0500
Steven Rostedt <[email protected]> wrote:
> On Tue, 8 Nov 2022 23:38:46 +0900
> Masami Hiramatsu (Google) <[email protected]> wrote:
>
> > > Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
> > > Signed-off-by: Shang XiaoJing <[email protected]>
> >
> > This looks good to me.
> >
> > Acked-by: Masami Hiramatsu (Google) <[email protected]>
>
> Hi Masami,
>
> Did you want me to pull these on top of your probes/urgent branch?
No, I think these patches are already queued on probes/urgent :)
https://kernel.googlesource.com/pub/scm/linux/kernel/git/trace/linux-trace.git/+/210880de4e3945d0ac028894df578063205bef61
>
> I'm going through all my patches now and will be starting the testing
> hopefully later this week.
Thanks!
>
> -- Steve
--
Masami Hiramatsu (Google) <[email protected]>
On Thu, 17 Nov 2022 16:14:53 +0900
Masami Hiramatsu (Google) <[email protected]> wrote:
> No, I think these patches are already queued on probes/urgent :)
>
> https://kernel.googlesource.com/pub/scm/linux/kernel/git/trace/linux-trace.git/+/210880de4e3945d0ac028894df578063205bef61
Bah, for some reason, when I searched the git log of that branch, it didn't
show up :-/
-- Steve