| Message ID | 20240810034209.552795-1-yangyun50@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fuse: fix race conditions on fi->nlookup | expand |
On 8/10/24 05:42, yangyun wrote: > Lock on fi->nlookup is missed in fuse_fill_super_submount(). Add lock > on it to prevent race conditions. > > Fixes: 1866d779d5d2 ("fuse: Allow fuse_fill_super_common() for submounts") > Cc: stable@vger.kernel.org > Signed-off-by: yangyun <yangyun50@huawei.com> > --- > fs/fuse/inode.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c > index 99e44ea7d875..2e220f245ceb 100644 > --- a/fs/fuse/inode.c > +++ b/fs/fuse/inode.c > @@ -1593,7 +1593,9 @@ static int fuse_fill_super_submount(struct super_block *sb, > * that, though, so undo it here. > */ > fi = get_fuse_inode(root); > + spin_lock(&fi->lock); > fi->nlookup--; > + spin_unlock(&fi->lock); > > sb->s_d_op = &fuse_dentry_operations; > sb->s_root = d_make_root(root); LGTM Reviewed-by: Bernd Schubert <bschubert@ddn.com>
On Sat, 10 Aug 2024 at 05:42, yangyun <yangyun50@huawei.com> wrote: > > Lock on fi->nlookup is missed in fuse_fill_super_submount(). Add lock > on it to prevent race conditions. It's okay to do this without lockinghere, because this is a brand new superblock and and a brand new root inode for that superblock, so there's no possible access from outside this function. So just a comment should suffice. Thanks, Miklos
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 99e44ea7d875..2e220f245ceb 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1593,7 +1593,9 @@ static int fuse_fill_super_submount(struct super_block *sb, * that, though, so undo it here. */ fi = get_fuse_inode(root); + spin_lock(&fi->lock); fi->nlookup--; + spin_unlock(&fi->lock); sb->s_d_op = &fuse_dentry_operations; sb->s_root = d_make_root(root);
Lock on fi->nlookup is missed in fuse_fill_super_submount(). Add lock on it to prevent race conditions. Fixes: 1866d779d5d2 ("fuse: Allow fuse_fill_super_common() for submounts") Cc: stable@vger.kernel.org Signed-off-by: yangyun <yangyun50@huawei.com> --- fs/fuse/inode.c | 2 ++ 1 file changed, 2 insertions(+)