* [PATCH] tracing: Fix memory leak in tracing_err_log_open()
@ 2019-06-27 11:41 Takeshi Misawa
2019-06-28 1:02 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Takeshi Misawa @ 2019-06-27 11:41 UTC (permalink / raw)
To: Steven Rostedt, Ingo Molnar; +Cc: linux-kernel
If tracing_err_log_open() call seq_open(), allocated memory is not freed.
kmemleak report:
unreferenced object 0xffff92c0781d1100 (size 128):
comm "tail", pid 15116, jiffies 4295163855 (age 22.704s)
hex dump (first 32 bytes):
00 f0 08 e5 c0 92 ff ff 00 10 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<000000000d0687d5>] kmem_cache_alloc+0x11f/0x1e0
[<000000003e3039a8>] seq_open+0x2f/0x90
[<000000008dd36b7d>] tracing_err_log_open+0x67/0x140
[<000000005a431ae2>] do_dentry_open+0x1df/0x3a0
[<00000000a2910603>] vfs_open+0x2f/0x40
[<0000000038b0a383>] path_openat+0x2e8/0x1690
[<00000000fe025bda>] do_filp_open+0x9b/0x110
[<00000000483a5091>] do_sys_open+0x1ba/0x260
[<00000000c558b5fd>] __x64_sys_openat+0x20/0x30
[<000000006881ec07>] do_syscall_64+0x5a/0x130
[<00000000571c2e94>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this by calling seq_release() in tracing_err_log_fops.release().
Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
---
Dear Steven Rostedt
I found kmemleak in tracing subsystem, and try to create a patch.
Please consider this memory leak and patch.
Regards.
---
kernel/trace/trace.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 83e08b78dbee..574648798978 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7126,12 +7126,24 @@ static ssize_t tracing_err_log_write(struct file *file,
return count;
}
+static int tracing_err_log_release(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+
+ trace_array_put(tr);
+
+ if (file->private_data)
+ seq_release(inode, file);
+
+ return 0;
+}
+
static const struct file_operations tracing_err_log_fops = {
.open = tracing_err_log_open,
.write = tracing_err_log_write,
.read = seq_read,
.llseek = seq_lseek,
- .release = tracing_release_generic_tr,
+ .release = tracing_err_log_release,
};
static int tracing_buffers_open(struct inode *inode, struct file *filp)
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing: Fix memory leak in tracing_err_log_open()
2019-06-27 11:41 [PATCH] tracing: Fix memory leak in tracing_err_log_open() Takeshi Misawa
@ 2019-06-28 1:02 ` Steven Rostedt
2019-06-28 1:07 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2019-06-28 1:02 UTC (permalink / raw)
To: Tom Zanussi; +Cc: Takeshi Misawa, Ingo Molnar, linux-kernel
On Thu, 27 Jun 2019 20:41:16 +0900
Takeshi Misawa <jeliantsurux@gmail.com> wrote:
> If tracing_err_log_open() call seq_open(), allocated memory is not freed.
>
> kmemleak report:
>
> unreferenced object 0xffff92c0781d1100 (size 128):
> comm "tail", pid 15116, jiffies 4295163855 (age 22.704s)
> hex dump (first 32 bytes):
> 00 f0 08 e5 c0 92 ff ff 00 10 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<000000000d0687d5>] kmem_cache_alloc+0x11f/0x1e0
> [<000000003e3039a8>] seq_open+0x2f/0x90
> [<000000008dd36b7d>] tracing_err_log_open+0x67/0x140
> [<000000005a431ae2>] do_dentry_open+0x1df/0x3a0
> [<00000000a2910603>] vfs_open+0x2f/0x40
> [<0000000038b0a383>] path_openat+0x2e8/0x1690
> [<00000000fe025bda>] do_filp_open+0x9b/0x110
> [<00000000483a5091>] do_sys_open+0x1ba/0x260
> [<00000000c558b5fd>] __x64_sys_openat+0x20/0x30
> [<000000006881ec07>] do_syscall_64+0x5a/0x130
> [<00000000571c2e94>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Fix this by calling seq_release() in tracing_err_log_fops.release().
Tom,
Can you review this.
Thanks!
-- Steve
>
> Signed-off-by: Takeshi Misawa <jeliantsurux@gmail.com>
> ---
> Dear Steven Rostedt
>
> I found kmemleak in tracing subsystem, and try to create a patch.
> Please consider this memory leak and patch.
>
> Regards.
> ---
> kernel/trace/trace.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 83e08b78dbee..574648798978 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -7126,12 +7126,24 @@ static ssize_t tracing_err_log_write(struct file *file,
> return count;
> }
>
> +static int tracing_err_log_release(struct inode *inode, struct file *file)
> +{
> + struct trace_array *tr = inode->i_private;
> +
> + trace_array_put(tr);
> +
> + if (file->private_data)
> + seq_release(inode, file);
> +
> + return 0;
> +}
> +
> static const struct file_operations tracing_err_log_fops = {
> .open = tracing_err_log_open,
> .write = tracing_err_log_write,
> .read = seq_read,
> .llseek = seq_lseek,
> - .release = tracing_release_generic_tr,
> + .release = tracing_err_log_release,
> };
>
> static int tracing_buffers_open(struct inode *inode, struct file *filp)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tracing: Fix memory leak in tracing_err_log_open()
2019-06-28 1:02 ` Steven Rostedt
@ 2019-06-28 1:07 ` Steven Rostedt
0 siblings, 0 replies; 3+ messages in thread
From: Steven Rostedt @ 2019-06-28 1:07 UTC (permalink / raw)
To: Takeshi Misawa; +Cc: Tom Zanussi, Ingo Molnar, linux-kernel
On Thu, 27 Jun 2019 21:02:31 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> > +++ b/kernel/trace/trace.c
> > @@ -7126,12 +7126,24 @@ static ssize_t tracing_err_log_write(struct file *file,
> > return count;
> > }
> >
> > +static int tracing_err_log_release(struct inode *inode, struct file *file)
> > +{
> > + struct trace_array *tr = inode->i_private;
> > +
> > + trace_array_put(tr);
> > +
> > + if (file->private_data)
Actually, I think it is safer to have the condition be:
if (file->f_mode & FMODE_READ)
As that would match the open.
Takeshi,
Can you send a v2?
Thanks!
-- Steve
> > + seq_release(inode, file);
> > +
> > + return 0;
> > +}
> > +
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-06-27 11:41 [PATCH] tracing: Fix memory leak in tracing_err_log_open() Takeshi Misawa
2019-06-28 1:02 ` Steven Rostedt
2019-06-28 1:07 ` Steven Rostedt
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