f2fs: don't access node/meta inode mapping after iput

This fixes wrong access of address spaces of node and meta inodes after iput.

Fixes: 60aa4d5536ab ("f2fs: fix use-after-free issue when accessing sbi->stat_info")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index ebcc121..503fde8 100644 (file)
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -96,8 +96,10 @@ static void update_general_status(struct f2fs_sb_info *sbi)
        si->free_secs = free_sections(sbi);
        si->prefree_count = prefree_segments(sbi);
        si->dirty_count = dirty_segments(sbi);
-       si->node_pages = NODE_MAPPING(sbi)->nrpages;
-       si->meta_pages = META_MAPPING(sbi)->nrpages;
+       if (sbi->node_inode)
+               si->node_pages = NODE_MAPPING(sbi)->nrpages;
+       if (sbi->meta_inode)
+               si->meta_pages = META_MAPPING(sbi)->nrpages;
        si->nats = NM_I(sbi)->nat_cnt;
        si->dirty_nats = NM_I(sbi)->dirty_nat_cnt;
        si->sits = MAIN_SEGS(sbi);
@@ -175,7 +177,6 @@ static void update_sit_info(struct f2fs_sb_info *sbi)
 static void update_mem_info(struct f2fs_sb_info *sbi)
 {
        struct f2fs_stat_info *si = F2FS_STAT(sbi);
-       unsigned npages;
        int i;
 
        if (si->base_mem)
@@ -258,10 +259,14 @@ get_cache:
                                                sizeof(struct extent_node);
 
        si->page_mem = 0;
-       npages = NODE_MAPPING(sbi)->nrpages;
-       si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
-       npages = META_MAPPING(sbi)->nrpages;
-       si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+       if (sbi->node_inode) {
+               unsigned npages = NODE_MAPPING(sbi)->nrpages;
+               si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+       }
+       if (sbi->meta_inode) {
+               unsigned npages = META_MAPPING(sbi)->nrpages;
+               si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+       }
 }
 
 static int stat_show(struct seq_file *s, void *v)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index c46a1d4..14f033e 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1075,7 +1075,10 @@ static void f2fs_put_super(struct super_block *sb)
        f2fs_bug_on(sbi, sbi->fsync_node_num);
 
        iput(sbi->node_inode);
+       sbi->node_inode = NULL;
+
        iput(sbi->meta_inode);
+       sbi->meta_inode = NULL;
 
        /*
         * iput() can update stat information, if f2fs_write_checkpoint()
@@ -3410,6 +3413,7 @@ free_node_inode:
        f2fs_release_ino_entry(sbi, true);
        truncate_inode_pages_final(NODE_MAPPING(sbi));
        iput(sbi->node_inode);
+       sbi->node_inode = NULL;
 free_stats:
        f2fs_destroy_stats(sbi);
 free_nm:
@@ -3422,6 +3426,7 @@ free_devices:
 free_meta_inode:
        make_bad_inode(sbi->meta_inode);
        iput(sbi->meta_inode);
+       sbi->meta_inode = NULL;
 free_io_dummy:
        mempool_destroy(sbi->write_io_dummy);
 free_percpu: