| From e3471db97a893925e1d5d55deeba59ea337ce70f Mon Sep 17 00:00:00 2001 |
| From: Johannes Thumshirn <jth@kernel.org> |
| Date: Thu, 5 Dec 2019 14:19:57 +0100 |
| Subject: [PATCH] btrfs: fix possible NULL-pointer dereference in integrity |
| checks |
| |
| commit 3dbd351df42109902fbcebf27104149226a4fcd9 upstream. |
| |
| 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@kernel.org> |
| Reviewed-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: David Sterba <dsterba@suse.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c |
| index b0c8094528d1..3d2e2fdbdfb6 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", |
| -- |
| 2.7.4 |
| |
