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| author |   Javier Pello <javier.pello@urjc.es> | 2021-07-14 18:54:48 +0200 |
|---|---|---|
| committer |   Jan Kara <jack@suse.cz> | 2021-07-16 12:36:51 +0200 |
| commit | 728d392f8a799f037812d0f2b254fb3b5e115fcf (patch) | |
| tree | f7786885c6af432e6314b24afde73f34a8705663 /fs/ext2/dir.c | |
| parent | reiserfs: add check for root_inode in reiserfs_fill_super (diff) | |
| download | linux-dev-728d392f8a799f037812d0f2b254fb3b5e115fcf.tar.xz linux-dev-728d392f8a799f037812d0f2b254fb3b5e115fcf.zip | |
fs/ext2: Avoid page_address on pages returned by ext2_get_page
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.
Link: https://lore.kernel.org/r/20210714185448.8707ac239e9f12b3a7f5b9f9@urjc.es
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Javier Pello <javier.pello@urjc.es>
Fixes: 782b76d7abdf ("fs/ext2: Replace kmap() with kmap_local_page()")
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/ext2/dir.c')
| -rw-r--r-- | fs/ext2/dir.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c index 14292dba3a12..2c2f179b6977 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; } } @@ -584,10 +584,10 @@ out_unlock: * 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, + char *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); @@ -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 - kaddr; pos = page_offset(page) + from; lock_page(page); err = ext2_prepare_chunk(page, pos, to - from); |