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| author | Kees Cook <keescook@chromium.org> | 2024-02-22 18:48:46 +0100 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2024-02-22 19:37:21 +0100 |
| commit | a43e0fc5e9134a46515de2f2f8d4100b74e50de3 (patch) | |
| tree | 6c459af0eb6a68a25045f1b146e3a5d0bdbe6bd5 /fs | |
| parent | Linux 6.8-rc2 (diff) | |
| download | linux-a43e0fc5e9134a46515de2f2f8d4100b74e50de3.tar.xz linux-a43e0fc5e9134a46515de2f2f8d4100b74e50de3.zip | |
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')
| -rw-r--r-- | fs/pstore/inode.c | 10 |
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; } /* |