From: Johannes Thumshirn <jth@xxxxxxxxxx> [ Upstream commit 3dbd351df42109902fbcebf27104149226a4fcd9 ] A user reports a possible NULL-pointer dereference in btrfsic_process_superblock(). We are assigning state->fs_info to a local fs_info variable and afterwards checking for the presence of state. While we would BUG_ON() a NULL state anyways, we can also just remove the local fs_info copy, as fs_info is only used once as the first argument for btrfs_num_copies(). There we can just pass in state->fs_info as well. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205003 Signed-off-by: Johannes Thumshirn <jth@xxxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/btrfs/check-integrity.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c index 0b52ab4cb9649..72c70f59fc605 100644 --- a/fs/btrfs/check-integrity.c +++ b/fs/btrfs/check-integrity.c @@ -629,7 +629,6 @@ static struct btrfsic_dev_state *btrfsic_dev_state_hashtable_lookup(dev_t dev, static int btrfsic_process_superblock(struct btrfsic_state *state, struct btrfs_fs_devices *fs_devices) { - struct btrfs_fs_info *fs_info = state->fs_info; struct btrfs_super_block *selected_super; struct list_head *dev_head = &fs_devices->devices; struct btrfs_device *device; @@ -700,7 +699,7 @@ static int btrfsic_process_superblock(struct btrfsic_state *state, break; } - num_copies = btrfs_num_copies(fs_info, next_bytenr, + num_copies = btrfs_num_copies(state->fs_info, next_bytenr, state->metablock_size); if (state->print_mask & BTRFSIC_PRINT_MASK_NUM_COPIES) pr_info("num_copies(log_bytenr=%llu) = %d\n", -- 2.20.1
