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authorKees Cook <keescook@chromium.org>2024-02-22 09:48:46 -0800
committerKees Cook <keescook@chromium.org>2024-02-22 10:37:21 -0800
commita43e0fc5e9134a46515de2f2f8d4100b74e50de3 (patch)
tree6c459af0eb6a68a25045f1b146e3a5d0bdbe6bd5 /fs/pstore
parent41bccc98fb7931d63d03f326a746ac4d429c1dd3 (diff)
pstore: inode: Only d_invalidate() is needed
Unloading a modular pstore backend with records in pstorefs would trigger the dput() double-drop warning: WARNING: CPU: 0 PID: 2569 at fs/dcache.c:762 dput.part.0+0x3f3/0x410 Using the combo of d_drop()/dput() (as mentioned in Documentation/filesystems/vfs.rst) isn't the right approach here, and leads to the reference counting problem seen above. Use d_invalidate() and update the code to not bother checking for error codes that can never happen. Suggested-by: Alexander Viro <viro@zeniv.linux.org.uk> Fixes: 609e28bb139e ("pstore: Remove filesystem records when backend is unregistered") Signed-off-by: Kees Cook <keescook@chromium.org> --- Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tony Luck <tony.luck@intel.com> Cc: linux-hardening@vger.kernel.org
Diffstat (limited to 'fs/pstore')
-rw-r--r--fs/pstore/inode.c10
1 files changed, 3 insertions, 7 deletions
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index d0d9bfdad30c..56815799ce79 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -307,7 +307,6 @@ int pstore_put_backend_records(struct pstore_info *psi)
{
struct pstore_private *pos, *tmp;
struct dentry *root;
- int rc = 0;
root = psinfo_lock_root();
if (!root)
@@ -317,11 +316,8 @@ int pstore_put_backend_records(struct pstore_info *psi)
list_for_each_entry_safe(pos, tmp, &records_list, list) {
if (pos->record->psi == psi) {
list_del_init(&pos->list);
- rc = simple_unlink(d_inode(root), pos->dentry);
- if (WARN_ON(rc))
- break;
- d_drop(pos->dentry);
- dput(pos->dentry);
+ d_invalidate(pos->dentry);
+ simple_unlink(d_inode(root), pos->dentry);
pos->dentry = NULL;
}
}
@@ -329,7 +325,7 @@ int pstore_put_backend_records(struct pstore_info *psi)
inode_unlock(d_inode(root));
- return rc;
+ return 0;
}
/*