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| author |   Naohiro Aota <naota@elisp.net> | 2018-07-27 09:04:55 +0900 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2018-08-06 13:13:04 +0200 |
| commit | 39379faaad79e3cf403a6904a08676b7850043ae (patch) | |
| tree | 6b7f07df694ff8e502a024f71a2dd0020f23e5c3 /fs/btrfs | |
| parent | btrfs: Exit gracefully when chunk map cannot be inserted to the tree (diff) | |
| download | linux-dev-39379faaad79e3cf403a6904a08676b7850043ae.tar.xz linux-dev-39379faaad79e3cf403a6904a08676b7850043ae.zip | |
btrfs: revert fs_devices state on error of btrfs_init_new_device
When btrfs hits error after modifying fs_devices in
btrfs_init_new_device() (such as btrfs_add_dev_item() returns error), it
leaves everything as is, but frees allocated btrfs_device. As a result,
fs_devices->devices and fs_devices->alloc_list contain already freed
btrfs_device, leading to later use-after-free bug.
Error path also messes the things like ->num_devices. While they go back
to the original value by unscanning btrfs devices, it is safe to revert
them here.
Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling")
Signed-off-by: Naohiro Aota <naota@elisp.net>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/volumes.c | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7218a79a0e57..da86706123ff 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2321,7 +2321,8 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path struct super_block *sb = fs_info->sb; struct rcu_string *name; struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; - u64 tmp; + u64 orig_super_total_bytes; + u64 orig_super_num_devices; int seeding_dev = 0; int ret = 0; bool unlocked = false; @@ -2417,12 +2418,14 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path if (!blk_queue_nonrot(q)) fs_devices->rotating = 1; - tmp = btrfs_super_total_bytes(fs_info->super_copy); + orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy); btrfs_set_super_total_bytes(fs_info->super_copy, - round_down(tmp + device->total_bytes, fs_info->sectorsize)); + round_down(orig_super_total_bytes + device->total_bytes, + fs_info->sectorsize)); - tmp = btrfs_super_num_devices(fs_info->super_copy); - btrfs_set_super_num_devices(fs_info->super_copy, tmp + 1); + orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices + 1); /* add sysfs device entry */ btrfs_sysfs_add_device_link(fs_devices, device); @@ -2502,6 +2505,22 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path error_sysfs: btrfs_sysfs_rm_device_link(fs_devices, device); + mutex_lock(&fs_info->fs_devices->device_list_mutex); + mutex_lock(&fs_info->chunk_mutex); + list_del_rcu(&device->dev_list); + list_del(&device->dev_alloc_list); + fs_info->fs_devices->num_devices--; + fs_info->fs_devices->open_devices--; + fs_info->fs_devices->rw_devices--; + fs_info->fs_devices->total_devices--; + fs_info->fs_devices->total_rw_bytes -= device->total_bytes; + atomic64_sub(device->total_bytes, &fs_info->free_chunk_space); + btrfs_set_super_total_bytes(fs_info->super_copy, + orig_super_total_bytes); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices); + mutex_unlock(&fs_info->chunk_mutex); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); error_trans: if (seeding_dev) sb->s_flags |= SB_RDONLY; |