2023-05-23 02:55:29

by Muchun Song

Subject: [PATCH v2] kernfs: fix missing kernfs_idr_lock to remove an ID from the IDR

The root->ino_idr is supposed to be protected by kernfs_idr_lock, fix
it.

Fixes: 488dee96bb62 ("kernfs: allow creating kernfs objects with arbitrary uid/gid")
Signed-off-by: Muchun Song <[email protected]>
---
v2:
- Open code the locking.

fs/kernfs/dir.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 45b6919903e6..5a1a4af9d3d2 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -655,7 +655,9 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root,
return kn;

err_out3:
+ spin_lock(&kernfs_idr_lock);
idr_remove(&root->ino_idr, (u32)kernfs_ino(kn));
+ spin_unlock(&kernfs_idr_lock);
err_out2:
kmem_cache_free(kernfs_node_cache, kn);
err_out1:
--
2.11.0

2023-05-23 02:58:38

by Tejun Heo

Subject: Re: [PATCH v2] kernfs: fix missing kernfs_idr_lock to remove an ID from the IDR

On Tue, May 23, 2023 at 10:40:17AM +0800, Muchun Song wrote:
> The root->ino_idr is supposed to be protected by kernfs_idr_lock, fix
> it.
>
> Fixes: 488dee96bb62 ("kernfs: allow creating kernfs objects with arbitrary uid/gid")
> Signed-off-by: Muchun Song <[email protected]>

Acked-by: Tejun Heo <[email protected]>

Thanks.

--
tejun