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| author | Filipe Manana <fdmanana@suse.com> | 2024-06-14 14:50:47 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2024-07-11 15:33:26 +0200 |
| commit | bb3868033a4cccff7be57e9145f2117cbdc91c11 (patch) | |
| tree | ab2d9bc127c05365303ff5e955a7edfabd5b29ef /fs/btrfs/ioctl.c | |
| parent | b7519157655bba3f885a856c1ec8b6560b51e214 (diff) | |
| download | lwn-bb3868033a4cccff7be57e9145f2117cbdc91c11.tar.gz lwn-bb3868033a4cccff7be57e9145f2117cbdc91c11.zip | |
btrfs: do not BUG_ON() when freeing tree block after error
When freeing a tree block, at btrfs_free_tree_block(), if we fail to
create a delayed reference we don't deal with the error and just do a
BUG_ON(). The error most likely to happen is -ENOMEM, and we have a
comment mentioning that only -ENOMEM can happen, but that is not true,
because in case qgroups are enabled any error returned from
btrfs_qgroup_trace_extent_post() (can be -EUCLEAN or anything returned
from btrfs_search_slot() for example) can be propagated back to
btrfs_free_tree_block().
So stop doing a BUG_ON() and return the error to the callers and make
them abort the transaction to prevent leaking space. Syzbot was
triggering this, likely due to memory allocation failure injection.
Reported-by: syzbot+a306f914b4d01b3958fe@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/000000000000fcba1e05e998263c@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/ioctl.c')
| -rw-r--r-- | fs/btrfs/ioctl.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 06447ee6d7ce..d28ebabe3720 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -714,6 +714,8 @@ static noinline int create_subvol(struct mnt_idmap *idmap, ret = btrfs_insert_root(trans, fs_info->tree_root, &key, root_item); if (ret) { + int ret2; + /* * Since we don't abort the transaction in this case, free the * tree block so that we don't leak space and leave the @@ -724,7 +726,9 @@ static noinline int create_subvol(struct mnt_idmap *idmap, btrfs_tree_lock(leaf); btrfs_clear_buffer_dirty(trans, leaf); btrfs_tree_unlock(leaf); - btrfs_free_tree_block(trans, objectid, leaf, 0, 1); + ret2 = btrfs_free_tree_block(trans, objectid, leaf, 0, 1); + if (ret2 < 0) + btrfs_abort_transaction(trans, ret2); free_extent_buffer(leaf); goto out; } |