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Wysocki" Cc: kernel@openvz.org, Alexander Atanasov , linux-kernel@vger.kernel.org Subject: [PATCH] devtmpfs: move NULLing the thread pointer before unregistering fs Date: Fri, 2 Dec 2022 14:45:01 +0200 Message-Id: <20221202124502.217462-1-alexander.atanasov@virtuozzo.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1751106923148596508?= X-GMAIL-MSGID: =?utf-8?q?1751106923148596508?= In commit 31c779f293b3 ("devtmpfs: fix the dangling pointer of global devtmpfsd thread") a dangling pointer on an error condition was fixed. But the fix left the dangling pointer during unregister_filesystem and printk calls. Improve the fix to clear the pointer before unregistration to close the window where the dangling pointer can be potentially used. Make it clear the pointer at only one place in the function. Signed-off-by: Alexander Atanasov --- drivers/base/devtmpfs.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) base-commit: b7b275e60bcd5f89771e865a8239325f86d9927d diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index e4bffeabf344..773e66ef5642 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -472,17 +472,15 @@ int __init devtmpfs_init(void) } thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); - if (!IS_ERR(thread)) { + if (!IS_ERR(thread)) wait_for_completion(&setup_done); - } else { + else err = PTR_ERR(thread); - thread = NULL; - } if (err) { + thread = NULL; printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); unregister_filesystem(&dev_fs_type); - thread = NULL; return err; }