redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

btrfs: scrub: Set bbio to NULL before calling btrfs_map_block

Browse source 
We usually call btrfs_put_bbio() when btrfs_map_block() failed,
btrfs_put_bbio() works right whether bbio is a valid value, or NULL.

But there is a exception, in some case, btrfs_map_block() will return
fail without touching *bbio(keeping its original value), and if bbio
was not initialized yet, invalid memory accessing will happened.

Above case is in scrub_missing_raid56_pages(), and similar case in
scrub_raid56_parity().

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Zhao Lei 2016-05-17 17:37:38 +08:00 committed by David Sterba
parent 2d324f59f3
commit f1fee6534d
1 changed files with 2 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
fs/btrfs/scrub.c
View file

@ -2181,7 +2181,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock)
struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info;
u64 length = sblock->page_count * PAGE_SIZE; u64 length = sblock->page_count * PAGE_SIZE;
u64 logical = sblock->pagev[0]->logical; u64 logical = sblock->pagev[0]->logical;
struct btrfs_bio *bbio; struct btrfs_bio *bbio = NULL;
struct bio *bio; struct bio *bio;
struct btrfs_raid_bio *rbio; struct btrfs_raid_bio *rbio;
int ret; int ret;
@ -2982,6 +2982,7 @@ again:
extent_len); extent_len);
mapped_length = extent_len; mapped_length = extent_len;
bbio = NULL;
ret = btrfs_map_block(fs_info, READ, extent_logical, ret = btrfs_map_block(fs_info, READ, extent_logical,
&mapped_length, &bbio, 0); &mapped_length, &bbio, 0);
if (!ret) { if (!ret) {