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ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page
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Since ocfs2_cow_file_pos will invoke ocfs2_refcount_icow with a NULL as
the struct file pointer, it finally result in a null pointer dereference
in ocfs2_duplicate_clusters_by_page.

This patch replace file pointer with inode pointer in
cow_duplicate_clusters to fix this issue.

[jeff.liu@oracle.com: rebased patch against linux-next tree]
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Tao Ma <tm@tao.ma>
Tested-by: David Weber <wb@munzinger.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tiger Yang authored and Linus Torvalds committed Aug 14, 2013
1 parent 6115ea2 commit c7dd339
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Showing 5 changed files with 16 additions and 53 deletions.
2 changes: 1 addition & 1 deletion fs/ocfs2/aops.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1757,7 +1757,7 @@ int ocfs2_write_begin_nolock(struct file *filp,
goto out;
} else if (ret == 1) {
clusters_need = wc->w_clen;
ret = ocfs2_refcount_cow(inode, filp, di_bh,
ret = ocfs2_refcount_cow(inode, di_bh,
wc->w_cpos, wc->w_clen, UINT_MAX);
if (ret) {
mlog_errno(ret);
Expand Down
6 changes: 3 additions & 3 deletions fs/ocfs2/file.c
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Original file line number Diff line number Diff line change
Expand Up @@ -370,7 +370,7 @@ static int ocfs2_cow_file_pos(struct inode *inode,
if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
goto out;

return ocfs2_refcount_cow(inode, NULL, fe_bh, cpos, 1, cpos+1);
return ocfs2_refcount_cow(inode, fe_bh, cpos, 1, cpos+1);

out:
return status;
Expand Down Expand Up @@ -899,7 +899,7 @@ static int ocfs2_zero_extend_get_range(struct inode *inode,
zero_clusters = last_cpos - zero_cpos;

if (needs_cow) {
rc = ocfs2_refcount_cow(inode, NULL, di_bh, zero_cpos,
rc = ocfs2_refcount_cow(inode, di_bh, zero_cpos,
zero_clusters, UINT_MAX);
if (rc) {
mlog_errno(rc);
Expand Down Expand Up @@ -2078,7 +2078,7 @@ static int ocfs2_prepare_inode_for_refcount(struct inode *inode,

*meta_level = 1;

ret = ocfs2_refcount_cow(inode, file, di_bh, cpos, clusters, UINT_MAX);
ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
if (ret)
mlog_errno(ret);
out:
Expand Down
2 changes: 1 addition & 1 deletion fs/ocfs2/move_extents.c
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Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,7 @@ static int __ocfs2_move_extent(handle_t *handle,
u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);
u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);

ret = ocfs2_duplicate_clusters_by_page(handle, context->file, cpos,
ret = ocfs2_duplicate_clusters_by_page(handle, inode, cpos,
p_cpos, new_p_cpos, len);
if (ret) {
mlog_errno(ret);
Expand Down
53 changes: 8 additions & 45 deletions fs/ocfs2/refcounttree.c
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Original file line number Diff line number Diff line change
Expand Up @@ -49,7 +49,6 @@

struct ocfs2_cow_context {
struct inode *inode;
struct file *file;
u32 cow_start;
u32 cow_len;
struct ocfs2_extent_tree data_et;
Expand All @@ -66,7 +65,7 @@ struct ocfs2_cow_context {
u32 *num_clusters,
unsigned int *extent_flags);
int (*cow_duplicate_clusters)(handle_t *handle,
struct file *file,
struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
};
Expand Down Expand Up @@ -2922,14 +2921,12 @@ static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
}

int ocfs2_duplicate_clusters_by_page(handle_t *handle,
struct file *file,
struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len)
{
int ret = 0, partial;
struct inode *inode = file_inode(file);
struct ocfs2_caching_info *ci = INODE_CACHE(inode);
struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
struct super_block *sb = inode->i_sb;
u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
struct page *page;
pgoff_t page_index;
Expand Down Expand Up @@ -2978,13 +2975,6 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
BUG_ON(PageDirty(page));

if (PageReadahead(page)) {
page_cache_async_readahead(mapping,
&file->f_ra, file,
page, page_index,
readahead_pages);
}

if (!PageUptodate(page)) {
ret = block_read_full_page(page, ocfs2_get_block);
if (ret) {
Expand All @@ -3004,7 +2994,8 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
}
}

ocfs2_map_and_dirty_page(inode, handle, from, to,
ocfs2_map_and_dirty_page(inode,
handle, from, to,
page, 0, &new_block);
mark_page_accessed(page);
unlock:
Expand All @@ -3020,12 +3011,11 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
}

int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
struct file *file,
struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len)
{
int ret = 0;
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
struct ocfs2_caching_info *ci = INODE_CACHE(inode);
int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
Expand Down Expand Up @@ -3150,7 +3140,7 @@ static int ocfs2_replace_clusters(handle_t *handle,

/*If the old clusters is unwritten, no need to duplicate. */
if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
ret = context->cow_duplicate_clusters(handle, context->file,
ret = context->cow_duplicate_clusters(handle, context->inode,
cpos, old, new, len);
if (ret) {
mlog_errno(ret);
Expand Down Expand Up @@ -3428,35 +3418,12 @@ static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
return ret;
}

static void ocfs2_readahead_for_cow(struct inode *inode,
struct file *file,
u32 start, u32 len)
{
struct address_space *mapping;
pgoff_t index;
unsigned long num_pages;
int cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;

if (!file)
return;

mapping = file->f_mapping;
num_pages = (len << cs_bits) >> PAGE_CACHE_SHIFT;
if (!num_pages)
num_pages = 1;

index = ((loff_t)start << cs_bits) >> PAGE_CACHE_SHIFT;
page_cache_sync_readahead(mapping, &file->f_ra, file,
index, num_pages);
}

/*
* Starting at cpos, try to CoW write_len clusters. Don't CoW
* past max_cpos. This will stop when it runs into a hole or an
* unrefcounted extent.
*/
static int ocfs2_refcount_cow_hunk(struct inode *inode,
struct file *file,
struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos)
{
Expand Down Expand Up @@ -3485,8 +3452,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,

BUG_ON(cow_len == 0);

ocfs2_readahead_for_cow(inode, file, cow_start, cow_len);

context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
if (!context) {
ret = -ENOMEM;
Expand All @@ -3508,7 +3473,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
context->ref_root_bh = ref_root_bh;
context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
context->get_clusters = ocfs2_di_get_clusters;
context->file = file;

ocfs2_init_dinode_extent_tree(&context->data_et,
INODE_CACHE(inode), di_bh);
Expand Down Expand Up @@ -3537,7 +3501,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
* clusters between cpos and cpos+write_len are safe to modify.
*/
int ocfs2_refcount_cow(struct inode *inode,
struct file *file,
struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos)
{
Expand All @@ -3557,7 +3520,7 @@ int ocfs2_refcount_cow(struct inode *inode,
num_clusters = write_len;

if (ext_flags & OCFS2_EXT_REFCOUNTED) {
ret = ocfs2_refcount_cow_hunk(inode, file, di_bh, cpos,
ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
num_clusters, max_cpos);
if (ret) {
mlog_errno(ret);
Expand Down
6 changes: 3 additions & 3 deletions fs/ocfs2/refcounttree.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,7 +53,7 @@ int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
int *credits,
int *ref_blocks);
int ocfs2_refcount_cow(struct inode *inode,
struct file *filep, struct buffer_head *di_bh,
struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos);

typedef int (ocfs2_post_refcount_func)(struct inode *inode,
Expand Down Expand Up @@ -85,11 +85,11 @@ int ocfs2_refcount_cow_xattr(struct inode *inode,
u32 cpos, u32 write_len,
struct ocfs2_post_refcount *post);
int ocfs2_duplicate_clusters_by_page(handle_t *handle,
struct file *file,
struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
struct file *file,
struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
int ocfs2_cow_sync_writeback(struct super_block *sb,
Expand Down

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