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| author | Chunyu Hu <chuhu@redhat.com> | 2018-06-10 03:51:24 +0800 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-06-27 20:44:38 -0400 |
| commit | 877f919e192a09e77962a13d7165783027dee5fd (patch) | |
| tree | cd5e37a5d4d3fc4483816d929d8c65626ebf1132 /fs | |
| parent | ce397d215ccd07b8ae3f71db689aedb85d56ab40 (diff) | |
| download | lwn-877f919e192a09e77962a13d7165783027dee5fd.tar.gz lwn-877f919e192a09e77962a13d7165783027dee5fd.zip | |
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 <hch@lst.de>
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/generic.c | 11 |
1 files changed, 10 insertions, 1 deletions
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, |