diff options
| author | David Howells <dhowells@redhat.com> | 2023-08-08 07:34:20 -0400 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-08-15 08:32:30 +0200 |
| commit | d80a8f1b58c2bc8d7c6bfb65401ea4f7ec8cddc2 (patch) | |
| tree | f20b825962286f47e36e6e4e3d0f0e4a62549f16 /fs/fs_context.c | |
| parent | 4352b8cd66e22952210e8205312d2b9ecd70be54 (diff) | |
vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior to sget_fc() being called,
leading to failure to match existing superblocks.
This bug leads to messages like the following appearing in dmesg when
fscache is enabled:
NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)
Fix this by adding a new LSM hook to load fc->security for submount
creation.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode")
Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230808-master-v9-1-e0ecde888221@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/fs_context.c')
| -rw-r--r-- | fs/fs_context.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/fs/fs_context.c b/fs/fs_context.c index 851214d1d013..375023e40161 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -315,10 +315,31 @@ struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, } EXPORT_SYMBOL(fs_context_for_reconfigure); +/** + * fs_context_for_submount: allocate a new fs_context for a submount + * @type: file_system_type of the new context + * @reference: reference dentry from which to copy relevant info + * + * Allocate a new fs_context suitable for a submount. This also ensures that + * the fc->security object is inherited from @reference (if needed). + */ struct fs_context *fs_context_for_submount(struct file_system_type *type, struct dentry *reference) { - return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT); + struct fs_context *fc; + int ret; + + fc = alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT); + if (IS_ERR(fc)) + return fc; + + ret = security_fs_context_submount(fc, reference->d_sb); + if (ret) { + put_fs_context(fc); + return ERR_PTR(ret); + } + + return fc; } EXPORT_SYMBOL(fs_context_for_submount); |