From 9886e836a6a5dbd273dc55b17e713f0a188d137f Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 27 Aug 2009 13:09:06 +0100 Subject: [PATCH] AFS: Stop readlink() on AFS crashing due to NULL 'file' ptr kAFS crashes when asked to read a symbolic link because page_getlink() passes a NULL file pointer to read_mapping_page(), but afs_readpage() expects a file pointer from which to extract a key. Modify afs_readpage() to request the appropriate key from the calling process's keyrings if a file struct is not supplied with one attached. Signed-off-by: David Howells Acked-by: Anton Blanchard Signed-off-by: Linus Torvalds --- fs/afs/file.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/afs/file.c b/fs/afs/file.c index 0149dab365e7..681c2a7b013f 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -134,9 +134,16 @@ static int afs_readpage(struct file *file, struct page *page) inode = page->mapping->host; - ASSERT(file != NULL); - key = file->private_data; - ASSERT(key != NULL); + if (file) { + key = file->private_data; + ASSERT(key != NULL); + } else { + key = afs_request_key(AFS_FS_S(inode->i_sb)->volume->cell); + if (IS_ERR(key)) { + ret = PTR_ERR(key); + goto error_nokey; + } + } _enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index); @@ -207,12 +214,17 @@ static int afs_readpage(struct file *file, struct page *page) unlock_page(page); } + if (!file) + key_put(key); _leave(" = 0"); return 0; error: SetPageError(page); unlock_page(page); + if (!file) + key_put(key); +error_nokey: _leave(" = %d", ret); return ret; } -- 2.30.2