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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-05-03 11:31:22 -0400 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-05-06 10:58:17 -0400 |
| commit | 4a8521b6bb81abba9d80d60b80908c77c9236ced (patch) | |
| tree | e287a6f9c76289877da366ce79855791b2c15a89 | |
| parent | b30b70ad8bffcde513d34d525820ec411f48e3d7 (diff) | |
| download | linux-4a8521b6bb81abba9d80d60b80908c77c9236ced.tar.gz | |
bcachefs: Inodes need extra padding for varint_decode_fast()
Reported-by: syzbot+66b9b74f6520068596a9@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
| -rw-r--r-- | fs/bcachefs/io_write.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/fs/bcachefs/io_write.c b/fs/bcachefs/io_write.c index f137252bccc575..b72cf31f72743c 100644 --- a/fs/bcachefs/io_write.c +++ b/fs/bcachefs/io_write.c @@ -199,9 +199,6 @@ static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans, u64 new_i_size, s64 i_sectors_delta) { - struct btree_iter iter; - struct bkey_i *k; - struct bkey_i_inode_v3 *inode; /* * Crazy performance optimization: * Every extent update needs to also update the inode: the inode trigger @@ -214,25 +211,36 @@ static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans, * lost, but that's fine. */ unsigned inode_update_flags = BTREE_UPDATE_NOJOURNAL; - int ret; - k = bch2_bkey_get_mut_noupdate(trans, &iter, BTREE_ID_inodes, + struct btree_iter iter; + struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes, SPOS(0, extent_iter->pos.inode, extent_iter->snapshot), BTREE_ITER_CACHED); - ret = PTR_ERR_OR_ZERO(k); + int ret = bkey_err(k); if (unlikely(ret)) return ret; - if (unlikely(k->k.type != KEY_TYPE_inode_v3)) { - k = bch2_inode_to_v3(trans, k); - ret = PTR_ERR_OR_ZERO(k); + /* + * varint_decode_fast(), in the inode .invalid method, reads up to 7 + * bytes past the end of the buffer: + */ + struct bkey_i *k_mut = bch2_trans_kmalloc_nomemzero(trans, bkey_bytes(k.k) + 8); + ret = PTR_ERR_OR_ZERO(k_mut); + if (unlikely(ret)) + goto err; + + bkey_reassemble(k_mut, k); + + if (unlikely(k_mut->k.type != KEY_TYPE_inode_v3)) { + k_mut = bch2_inode_to_v3(trans, k_mut); + ret = PTR_ERR_OR_ZERO(k_mut); if (unlikely(ret)) goto err; } - inode = bkey_i_to_inode_v3(k); + struct bkey_i_inode_v3 *inode = bkey_i_to_inode_v3(k_mut); if (!(le64_to_cpu(inode->v.bi_flags) & BCH_INODE_i_size_dirty) && new_i_size > le64_to_cpu(inode->v.bi_size)) { |