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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-08 03:43:31 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-08 03:43:31 +0000 |
| commit | 1327913aeadf5737e7ebf158f93632d6df2eba1d (patch) | |
| tree | 2ca5c2a3aa381788eca2580f72a2d5c60934b28a /mm/memcontrol.c | |
| parent | Adding upstream version 4.19.260. (diff) | |
| download | linux-1327913aeadf5737e7ebf158f93632d6df2eba1d.tar.xz linux-1327913aeadf5737e7ebf158f93632d6df2eba1d.zip | |
Adding upstream version 4.19.269.upstream/4.19.269
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f3aa6e621..bc4c61dcf 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4120,6 +4120,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, unsigned int efd, cfd; struct fd efile; struct fd cfile; + struct dentry *cdentry; const char *name; char *endp; int ret; @@ -4171,6 +4172,16 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, goto out_put_cfile; /* + * The control file must be a regular cgroup1 file. As a regular cgroup + * file can't be renamed, it's safe to access its name afterwards. + */ + cdentry = cfile.file->f_path.dentry; + if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) { + ret = -EINVAL; + goto out_put_cfile; + } + + /* * Determine the event callbacks and set them in @event. This used * to be done via struct cftype but cgroup core no longer knows * about these events. The following is crude but the whole thing @@ -4178,7 +4189,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, * * DO NOT ADD NEW FILES. */ - name = cfile.file->f_path.dentry->d_name.name; + name = cdentry->d_name.name; if (!strcmp(name, "memory.usage_in_bytes")) { event->register_event = mem_cgroup_usage_register_event; @@ -4202,7 +4213,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of, * automatically removed on cgroup destruction but the removal is * asynchronous, so take an extra ref on @css. */ - cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent, + cfile_css = css_tryget_online_from_dir(cdentry->d_parent, &memory_cgrp_subsys); ret = -EINVAL; if (IS_ERR(cfile_css)) |