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| author | Al Viro <viro@zeniv.linux.org.uk> | 2022-08-23 11:53:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-01 16:18:49 +0200 |
| commit | 9d64d2405f7d30d49818f6682acd0392348f0fdb (patch) | |
| tree | 6d8cb5c4bbb9f09467672410dec0ce8fadf8c8fe /drivers/android | |
| parent | eaf271ea844b8dea5256bd3c73e642ef13ce68a2 (diff) | |
| download | linux-9d64d2405f7d30d49818f6682acd0392348f0fdb.tar.gz | |
binderfs: rework superblock destruction
So far we relied on .put_super = binderfs_put_super() to destroy info we stashed in sb->s_fs_info. This gave us the required ordering between ->evict_inode() and sb->s_fs_info destruction. But the current implementation of binderfs_fill_super() has a memory leak in the rare circumstance that d_make_root() fails because ->put_super() is only called when sb->s_root is initialized. Fix this by removing ->put_super() and simply do all that work in binderfs_kill_super(). Reported-by: Dongliang Mu <mudongliangabcd@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Link: https://lore.kernel.org/r/20220823095339.853371-1-brauner@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android')
| -rw-r--r-- | drivers/android/binderfs.c | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c index 44939ea1874f..09b2ce7e4c34 100644 --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -339,22 +339,10 @@ static int binderfs_show_options(struct seq_file *seq, struct dentry *root) return 0; } -static void binderfs_put_super(struct super_block *sb) -{ - struct binderfs_info *info = sb->s_fs_info; - - if (info && info->ipc_ns) - put_ipc_ns(info->ipc_ns); - - kfree(info); - sb->s_fs_info = NULL; -} - static const struct super_operations binderfs_super_ops = { .evict_inode = binderfs_evict_inode, .show_options = binderfs_show_options, .statfs = simple_statfs, - .put_super = binderfs_put_super, }; static inline bool is_binderfs_control_device(const struct dentry *dentry) @@ -784,11 +772,27 @@ static int binderfs_init_fs_context(struct fs_context *fc) return 0; } +static void binderfs_kill_super(struct super_block *sb) +{ + struct binderfs_info *info = sb->s_fs_info; + + /* + * During inode eviction struct binderfs_info is needed. + * So first wipe the super_block then free struct binderfs_info. + */ + kill_litter_super(sb); + + if (info && info->ipc_ns) + put_ipc_ns(info->ipc_ns); + + kfree(info); +} + static struct file_system_type binder_fs_type = { .name = "binder", .init_fs_context = binderfs_init_fs_context, .parameters = binderfs_fs_parameters, - .kill_sb = kill_litter_super, + .kill_sb = binderfs_kill_super, .fs_flags = FS_USERNS_MOUNT, }; |