From 877f919e192a09e77962a13d7165783027dee5fd Mon Sep 17 00:00:00 2001 From: Chunyu Hu Date: Sun, 10 Jun 2018 03:51:24 +0800 Subject: proc: add proc_seq_release kmemleak reported some memory leak on reading proc files. After adding some debug lines, find that proc_seq_fops is using seq_release as release handler, which won't handle the free of 'private' field of seq_file, while in fact the open handler proc_seq_open could create the private data with __seq_open_private when state_size is greater than zero. So after reading files created with proc_create_seq_private, such as /proc/timer_list and /proc/vmallocinfo, the private mem of a seq_file is not freed. Fix it by adding the paired proc_seq_release as the default release handler of proc_seq_ops instead of seq_release. Fixes: 44414d82cfe0 ("proc: introduce proc_create_seq_private") Reviewed-by: Christoph Hellwig CC: Christoph Hellwig Signed-off-by: Chunyu Hu Signed-off-by: Al Viro --- fs/proc/generic.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'fs/proc') diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 6ac1c92997ea..bb1c1625b158 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -564,11 +564,20 @@ static int proc_seq_open(struct inode *inode, struct file *file) return seq_open(file, de->seq_ops); } +static int proc_seq_release(struct inode *inode, struct file *file) +{ + struct proc_dir_entry *de = PDE(inode); + + if (de->state_size) + return seq_release_private(inode, file); + return seq_release(inode, file); +} + static const struct file_operations proc_seq_fops = { .open = proc_seq_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = proc_seq_release, }; struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode, -- cgit v1.2.3