From: Javier Pello <javier.pello@xxxxxxx> Commit 782b76d7abdf02b12c46ed6f1e9bf715569027f7 ("fs/ext2: Replace kmap() with kmap_local_page()") replaced the kmap/kunmap calls in ext2_get_page/ext2_put_page with kmap_local_page/kunmap_local for efficiency reasons. As a necessary side change, the commit also made ext2_get_page (and ext2_find_entry and ext2_dotdot) return the mapping address along with the page itself, as it is required for kunmap_local, and converted uses of page_address on such pages to use the newly returned address instead. However, uses of page_address on such pages were missed in ext2_check_page and ext2_delete_entry, which triggers oopses if kmap_local_page happens to return an address from high memory. Fix this now by converting the remaining uses of page_address to use the right address, as returned by kmap_local_page. Signed-off-by: Javier Pello <javier.pello@xxxxxxx> Fixes: 782b76d7abdf fs/ext2: Replace kmap() with kmap_local_page() --- fs/ext2/dir.c | 20 ++++++++++---------- fs/ext2/ext2.h | 3 ++- fs/ext2/namei.c | 4 ++-- 3 files changed, 14 insertions(+), 13 deletions(-) diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c index 14292dba..0c59b4d3 100644 --- a/fs/ext2/dir.c +++ b/fs/ext2/dir.c @@ -106,12 +106,11 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len) return err; } -static bool ext2_check_page(struct page *page, int quiet) +static bool ext2_check_page(struct page *page, int quiet, char *kaddr) { struct inode *dir = page->mapping->host; struct super_block *sb = dir->i_sb; unsigned chunk_size = ext2_chunk_size(dir); - char *kaddr = page_address(page); u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count); unsigned offs, rec_len; unsigned limit = PAGE_SIZE; @@ -205,7 +204,8 @@ static struct page * ext2_get_page(struct inode *dir, unsigned long n, if (!IS_ERR(page)) { *page_addr = kmap_local_page(page); if (unlikely(!PageChecked(page))) { - if (PageError(page) || !ext2_check_page(page, quiet)) + if (PageError(page) || !ext2_check_page(page, quiet, + *page_addr)) goto fail; } } @@ -584,16 +584,16 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode) * ext2_delete_entry deletes a directory entry by merging it with the * previous entry. Page is up-to-date. */ -int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) +int ext2_delete_entry (struct ext2_dir_entry_2 *dir, struct page *page, + void *kaddr) { struct inode *inode = page->mapping->host; - char *kaddr = page_address(page); - unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1); - unsigned to = ((char *)dir - kaddr) + - ext2_rec_len_from_disk(dir->rec_len); + unsigned int delta = (char *)dir - (char *)kaddr; + unsigned int from = delta & ~(ext2_chunk_size(inode)-1); + unsigned int to = delta + ext2_rec_len_from_disk(dir->rec_len); loff_t pos; ext2_dirent * pde = NULL; - ext2_dirent * de = (ext2_dirent *) (kaddr + from); + ext2_dirent *de = (ext2_dirent *) ((char *)kaddr + from); int err; while ((char*)de < (char*)dir) { @@ -607,7 +607,7 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) de = ext2_next_entry(de); } if (pde) - from = (char*)pde - (char*)page_address(page); + from = (char *)pde - (char *)kaddr; pos = page_offset(page) + from; lock_page(page); err = ext2_prepare_chunk(page, pos, to - from); diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index b0a69482..7bda9379 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -740,7 +740,8 @@ extern int ext2_inode_by_name(struct inode *dir, extern int ext2_make_empty(struct inode *, struct inode *); extern struct ext2_dir_entry_2 *ext2_find_entry(struct inode *, const struct qstr *, struct page **, void **res_page_addr); -extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *); +extern int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct page *page, + void *kaddr); extern int ext2_empty_dir (struct inode *); extern struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct page **p, void **pa); extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, void *, diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 1f69b816..5f6b7560 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -293,7 +293,7 @@ static int ext2_unlink(struct inode * dir, struct dentry *dentry) goto out; } - err = ext2_delete_entry (de, page); + err = ext2_delete_entry (de, page, page_addr); ext2_put_page(page, page_addr); if (err) goto out; @@ -397,7 +397,7 @@ static int ext2_rename (struct user_namespace * mnt_userns, old_inode->i_ctime = current_time(old_inode); mark_inode_dirty(old_inode); - ext2_delete_entry(old_de, old_page); + ext2_delete_entry(old_de, old_page, old_page_addr); if (dir_de) { if (old_dir != new_dir) -- 2.30.1