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| author | Sahitya Tummala <stummala@codeaurora.org> | 2018-12-26 11:20:29 +0530 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2018-12-26 15:18:10 -0800 |
| commit | 60aa4d5536ab7fe32433ca1173bd9d6633851f27 (patch) | |
| tree | 8ed8366020971bf2bd773804ed058e1ae124a46a /fs/f2fs | |
| parent | bae0ee7a767ceeea6d8e170da3f228fbc7480331 (diff) | |
| download | lwn-60aa4d5536ab7fe32433ca1173bd9d6633851f27.tar.gz lwn-60aa4d5536ab7fe32433ca1173bd9d6633851f27.zip | |
f2fs: fix use-after-free issue when accessing sbi->stat_info
iput() on sbi->node_inode can update sbi->stat_info
in the below context, if the f2fs_write_checkpoint()
has failed with error.
f2fs_balance_fs_bg+0x1ac/0x1ec
f2fs_write_node_pages+0x4c/0x260
do_writepages+0x80/0xbc
__writeback_single_inode+0xdc/0x4ac
writeback_single_inode+0x9c/0x144
write_inode_now+0xc4/0xec
iput+0x194/0x22c
f2fs_put_super+0x11c/0x1e8
generic_shutdown_super+0x70/0xf4
kill_block_super+0x2c/0x5c
kill_f2fs_super+0x44/0x50
deactivate_locked_super+0x60/0x8c
deactivate_super+0x68/0x74
cleanup_mnt+0x40/0x78
Fix this by moving f2fs_destroy_stats() further below iput() in
both f2fs_put_super() and f2fs_fill_super() paths.
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/super.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 9b17e367aa8c..c46a1d4318d4 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1058,9 +1058,6 @@ static void f2fs_put_super(struct super_block *sb) f2fs_write_checkpoint(sbi, &cpc); } - /* f2fs_write_checkpoint can update stat informaion */ - f2fs_destroy_stats(sbi); - /* * normally superblock is clean, so we need to release this. * In addition, EIO will skip do checkpoint, we need this as well. @@ -1080,6 +1077,12 @@ static void f2fs_put_super(struct super_block *sb) iput(sbi->node_inode); iput(sbi->meta_inode); + /* + * iput() can update stat information, if f2fs_write_checkpoint() + * above failed with error. + */ + f2fs_destroy_stats(sbi); + /* destroy f2fs internal modules */ f2fs_destroy_node_manager(sbi); f2fs_destroy_segment_manager(sbi); @@ -3256,30 +3259,30 @@ try_onemore: f2fs_build_gc_manager(sbi); + err = f2fs_build_stats(sbi); + if (err) + goto free_nm; + /* get an inode for node space */ sbi->node_inode = f2fs_iget(sb, F2FS_NODE_INO(sbi)); if (IS_ERR(sbi->node_inode)) { f2fs_msg(sb, KERN_ERR, "Failed to read node inode"); err = PTR_ERR(sbi->node_inode); - goto free_nm; + goto free_stats; } - err = f2fs_build_stats(sbi); - if (err) - goto free_node_inode; - /* read root inode and dentry */ root = f2fs_iget(sb, F2FS_ROOT_INO(sbi)); if (IS_ERR(root)) { f2fs_msg(sb, KERN_ERR, "Failed to read root inode"); err = PTR_ERR(root); - goto free_stats; + goto free_node_inode; } if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size || !root->i_nlink) { iput(root); err = -EINVAL; - goto free_stats; + goto free_node_inode; } sb->s_root = d_make_root(root); /* allocate root dentry */ @@ -3403,12 +3406,12 @@ free_meta: free_root_inode: dput(sb->s_root); sb->s_root = NULL; -free_stats: - f2fs_destroy_stats(sbi); free_node_inode: f2fs_release_ino_entry(sbi, true); truncate_inode_pages_final(NODE_MAPPING(sbi)); iput(sbi->node_inode); +free_stats: + f2fs_destroy_stats(sbi); free_nm: f2fs_destroy_node_manager(sbi); free_sm: |