Hi, On Fri, 2019-06-28 at 19:56 +0900, Takeshi Misawa 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(). > > Signed-off-by: Takeshi Misawa <[email protected]> > --- > Dear Steven Rostedt > > Thanks for reviewing. > > > Actually, I think it is safer to have the condition be: > > > > if (file->f_mode & FMODE_READ) > > > > As that would match the open. > > > > Can you send a v2? > > I send a v2 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..4122ccde6ec2 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->f_mode & FMODE_READ) > + 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, > }; >
v2 looks good to me, thanks for sending this fix. Reviewed-by: Tom Zanussi <[email protected]> > static int tracing_buffers_open(struct inode *inode, struct file > *filp)
