diff options
| author | Christian Brauner <brauner@kernel.org> | 2024-12-19 18:01:32 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-12-22 11:03:10 +0100 |
| commit | ef4144ac2dec35d47de666f35cd873eb1be4172e (patch) | |
| tree | 0d8b83e84eb3d0dfaff7293eaadf2979684a4346 | |
| parent | 16ecd47cb0cd895c7c2f5dd5db50f6c005c51639 (diff) | |
pidfs: allow bind-mounts
Allow bind-mounting pidfds. Similar to nsfs let's allow bind-mounts for
pidfds. This allows pidfds to be safely recovered and checked for
process recycling.
Link: https://lore.kernel.org/r/20241219-work-pidfs-mount-v1-1-dbc56198b839@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/namespace.c | 10 | ||||
| -rw-r--r-- | fs/pidfs.c | 2 | ||||
| -rw-r--r-- | include/linux/pidfs.h | 1 |
3 files changed, 10 insertions, 3 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 23e81c2a1e3f..7baffa2ea582 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -32,6 +32,7 @@ #include <linux/fs_context.h> #include <linux/shmem_fs.h> #include <linux/mnt_idmapping.h> +#include <linux/pidfs.h> #include <linux/nospec.h> #include "pnode.h" @@ -2732,8 +2733,13 @@ static struct mount *__do_loopback(struct path *old_path, int recurse) if (IS_MNT_UNBINDABLE(old)) return mnt; - if (!check_mnt(old) && old_path->dentry->d_op != &ns_dentry_operations) - return mnt; + if (!check_mnt(old)) { + const struct dentry_operations *d_op = old_path->dentry->d_op; + + if (d_op != &ns_dentry_operations && + d_op != &pidfs_dentry_operations) + return mnt; + } if (!recurse && has_locked_children(old, old_path->dentry)) return mnt; diff --git a/fs/pidfs.c b/fs/pidfs.c index c5a51c69acc8..049352f973de 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -510,7 +510,7 @@ static char *pidfs_dname(struct dentry *dentry, char *buffer, int buflen) return dynamic_dname(buffer, buflen, "anon_inode:[pidfd]"); } -static const struct dentry_operations pidfs_dentry_operations = { +const struct dentry_operations pidfs_dentry_operations = { .d_delete = always_delete_dentry, .d_dname = pidfs_dname, .d_prune = stashed_dentry_prune, diff --git a/include/linux/pidfs.h b/include/linux/pidfs.h index df574d6708d4..7c830d0dec9a 100644 --- a/include/linux/pidfs.h +++ b/include/linux/pidfs.h @@ -6,5 +6,6 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags); void __init pidfs_init(void); void pidfs_add_pid(struct pid *pid); void pidfs_remove_pid(struct pid *pid); +extern const struct dentry_operations pidfs_dentry_operations; #endif /* _LINUX_PID_FS_H */ |