On 2023/7/13 22:14, Zheng Yejian wrote:
> kmemleak reports:
> unreferenced object 0xffff88814d14e200 (size 256):
> comm "cat", pid 336, jiffies 4294871818 (age 779.490s)
> hex dump (first 32 bytes):
> 04 00 01 03 00 00 00 00 08 00 00 00 00 00 00 00 ................
> 0c d8 c8 9b ff ff ff ff 04 5a ca 9b ff ff ff ff .........Z......
> backtrace:
> [<ffffffff9bdff18f>] __kmalloc+0x4f/0x140
> [<ffffffff9bc9238b>] trace_find_next_entry+0xbb/0x1d0
> [<ffffffff9bc9caef>] trace_print_lat_context+0xaf/0x4e0
> [<ffffffff9bc94490>] print_trace_line+0x3e0/0x950
> [<ffffffff9bc95499>] tracing_read_pipe+0x2d9/0x5a0
> [<ffffffff9bf03a43>] vfs_read+0x143/0x520
> [<ffffffff9bf04c2d>] ksys_read+0xbd/0x160
> [<ffffffff9d0f0edf>] do_syscall_64+0x3f/0x90
> [<ffffffff9d2000aa>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
>
> when reading file 'trace_pipe', 'iter->temp' is allocated or relocated
> in trace_find_next_entry() but not freed before 'trace_pipe' is closed.
>
> To fix it, free 'iter->temp' in tracing_release_pipe().
>
Sorry, forget the Fixes tag:(
Is following Fixes right?
Fixes: ff895103a84a ("tracing: Save off entry when peeking at next entry")
> Signed-off-by: Zheng Yejian <[email protected]>
> ---
> kernel/trace/trace.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 4529e264cb86..94cfaa884578 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -6764,6 +6764,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
>
> free_cpumask_var(iter->started);
> kfree(iter->fmt);
> + kfree(iter->temp);
> mutex_destroy(&iter->mutex);
> kfree(iter);
>
On Thu, 13 Jul 2023 22:23:20 +0800
Zheng Yejian <[email protected]> wrote:
> On 2023/7/13 22:14, Zheng Yejian wrote:
> > kmemleak reports:
> > unreferenced object 0xffff88814d14e200 (size 256):
> > comm "cat", pid 336, jiffies 4294871818 (age 779.490s)
> > hex dump (first 32 bytes):
> > 04 00 01 03 00 00 00 00 08 00 00 00 00 00 00 00 ................
> > 0c d8 c8 9b ff ff ff ff 04 5a ca 9b ff ff ff ff .........Z......
> > backtrace:
> > [<ffffffff9bdff18f>] __kmalloc+0x4f/0x140
> > [<ffffffff9bc9238b>] trace_find_next_entry+0xbb/0x1d0
> > [<ffffffff9bc9caef>] trace_print_lat_context+0xaf/0x4e0
> > [<ffffffff9bc94490>] print_trace_line+0x3e0/0x950
> > [<ffffffff9bc95499>] tracing_read_pipe+0x2d9/0x5a0
> > [<ffffffff9bf03a43>] vfs_read+0x143/0x520
> > [<ffffffff9bf04c2d>] ksys_read+0xbd/0x160
> > [<ffffffff9d0f0edf>] do_syscall_64+0x3f/0x90
> > [<ffffffff9d2000aa>] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
> >
> > when reading file 'trace_pipe', 'iter->temp' is allocated or relocated
> > in trace_find_next_entry() but not freed before 'trace_pipe' is closed.
> >
> > To fix it, free 'iter->temp' in tracing_release_pipe().
> >
>
> Sorry, forget the Fixes tag:(
>
> Is following Fixes right?
> Fixes: ff895103a84a ("tracing: Save off entry when peeking at next entry")
That's the one I already added ;-)
Don't worry too much about adding fixes, I will always analyze a fix patch
to find out what it actually fixes. If you add one, I'll still confirm it.
-- Steve
>
> > Signed-off-by: Zheng Yejian <[email protected]>
> > ---
> > kernel/trace/trace.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 4529e264cb86..94cfaa884578 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -6764,6 +6764,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file)
> >
> > free_cpumask_var(iter->started);
> > kfree(iter->fmt);
> > + kfree(iter->temp);
> > mutex_destroy(&iter->mutex);
> > kfree(iter);
> >