Messages in this thread Patch in this message | | | From | Defang Bo <> | Subject | [PATCH v3] fs/btrfs: avoid null pointer dereference if reloc control has not been initialized | Date | Tue, 5 Jan 2021 21:22:58 +0800 |
| |
Similar to commmit<389305b2aa68>("btrfs: relocation: Only remove reloc rb_trees if reloc control has been initialized"). It turns out that fs_info::reloc_ctl can be NULL in btrfs_recover_relocation(), as we allocate relocation control after all reloc roots have been verified,so there should be a check for rc to prevent null pointer dereference.
...... Signed-off-by: Defang Bo <bodefang@126.com> --- Changes since v2: - Resend this patch with manual reformatted.
Changes singe v1: - More accurate description for this patch to describe how the NULL can get there. --- ...... --- fs/btrfs/relocation.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 3602806d71bd..ca035712e08b 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -626,6 +626,9 @@ static int __must_check __add_reloc_root(struct btrfs_root *root) struct mapping_node *node; struct reloc_control *rc = fs_info->reloc_ctl; + if (!rc) + return 0; + node = kmalloc(sizeof(*node), GFP_NOFS); if (!node) return -ENOMEM; @@ -703,6 +706,9 @@ static int __update_reloc_root(struct btrfs_root *root) struct rb_node *rb_node; struct mapping_node *node = NULL; struct reloc_control *rc = fs_info->reloc_ctl; + + if (!rc) + return 0; spin_lock(&rc->reloc_root_tree.lock); rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, -- 2.7.4
| |