On 2025/08/01 3:03, Viacheslav Dubeyko wrote: > On Thu, 2025-07-31 at 07:02 +0900, Tetsuo Handa wrote: >> On 2025/07/31 4:24, Viacheslav Dubeyko wrote: >>> If we considering case HFS_CDR_DIR in hfs_read_inode(), then we know that it >>> could be HFS_POR_CNID, HFS_ROOT_CNID, or >= HFS_FIRSTUSER_CNID. Do you mean that >>> HFS_POR_CNID could be a problem in hfs_write_inode()? >> >> Yes. Passing one of 1, 5 or 15 instead of 2 from hfs_fill_super() triggers BUG() >> in hfs_write_inode(). We *MUST* validate at hfs_fill_super(), or hfs_read_inode() >> shall have to also reject 1, 5 and 15 (and as a result only accept 2). > > The fix should be in hfs_read_inode(). Currently, suggested solution hides the > issue but not fix the problem. Not fixing this problem might be hiding other issues, by hitting BUG() before other issues shows up. > Because b-tree nodes could contain multiple > corrupted records. Now, this patch checks only record for root folder. Let's > imagine that root folder record will be OK but another record(s) will be > corrupted in such way. Can the inode number of the record retrieved as a result of hfs_cat_find_brec(HFS_ROOT_CNID) be something other than HFS_ROOT_CNID ? If the inode number of the record retrieved as a result of hfs_cat_find_brec(HFS_ROOT_CNID) must be HFS_ROOT_CNID, this patch itself will be a complete fix for this problem. > Finally, we will have successful mount but operation with > corrupted record(s) will trigger this issue. So, I cannot consider this patch as > a complete fix of the problem. Did you try what you think as a fix of this problem (I guess something like shown below will be needed for avoid hitting BUG()) using https://lkml.kernel.org/r/a8f8da77-f099-499b-98e0-39ed159b6a2d@xxxxxxxxxxxxxxxxxxx ? diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c index a81ce7a740b9..d60395111ed5 100644 --- a/fs/hfs/inode.c +++ b/fs/hfs/inode.c @@ -81,7 +81,8 @@ static bool hfs_release_folio(struct folio *folio, gfp_t mask) tree = HFS_SB(sb)->cat_tree; break; default: - BUG(); + pr_err("detected unknown inode %lu, running fsck.hfs is recommended.\n", + inode->i_ino); return false; } @@ -305,11 +306,31 @@ static int hfs_test_inode(struct inode *inode, void *data) case HFS_CDR_FIL: return inode->i_ino == be32_to_cpu(rec->file.FlNum); default: - BUG(); + pr_err("detected unknown type %u, running fsck.hfs is recommended.\n", rec->type); return 1; } } +static bool is_bad_id(unsigned long ino) +{ + switch (ino) { + case 0: + case 3: + case 4: + case 6: + case 7: + case 8: + case 9: + case 10: + case 11: + case 12: + case 13: + case 14: + return true; + } + return false; +} + /* * hfs_read_inode */ @@ -348,6 +369,10 @@ static int hfs_read_inode(struct inode *inode, void *data) } inode->i_ino = be32_to_cpu(rec->file.FlNum); + if (is_bad_id(inode->i_ino)) { + make_bad_inode(inode); + break; + } inode->i_mode = S_IRUGO | S_IXUGO; if (!(rec->file.Flags & HFS_FIL_LOCK)) inode->i_mode |= S_IWUGO; @@ -358,9 +383,15 @@ static int hfs_read_inode(struct inode *inode, void *data) inode->i_op = &hfs_file_inode_operations; inode->i_fop = &hfs_file_operations; inode->i_mapping->a_ops = &hfs_aops; + if (inode->i_ino < 16) + pr_info("HFS_CDR_FIL i_ino=%ld\n", inode->i_ino); break; case HFS_CDR_DIR: inode->i_ino = be32_to_cpu(rec->dir.DirID); + if (is_bad_id(inode->i_ino)) { + make_bad_inode(inode); + break; + } inode->i_size = be16_to_cpu(rec->dir.Val) + 2; HFS_I(inode)->fs_blocks = 0; inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask); @@ -368,6 +399,8 @@ static int hfs_read_inode(struct inode *inode, void *data) inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, hfs_m_to_utime(rec->dir.MdDat)))); inode->i_op = &hfs_dir_inode_operations; inode->i_fop = &hfs_dir_operations; + if (inode->i_ino < 16) + pr_info("HFS_CDR_DIR i_ino=%ld\n", inode->i_ino); break; default: make_bad_inode(inode); @@ -441,7 +474,8 @@ int hfs_write_inode(struct inode *inode, struct writeback_control *wbc) hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree); return 0; default: - BUG(); + pr_err("detected unknown inode %lu, running fsck.hfs is recommended.\n", + inode->i_ino); return -EIO; } } # for i in $(seq 0 15); do timeout 1 unshare -m ./hfs $i; done # dmesg | grep fsck [ 52.563547] [ T479] hfs: detected unknown inode 1, running fsck.hfs is recommended. [ 56.606238] [ T255] hfs: detected unknown inode 5, running fsck.hfs is recommended. [ 66.694795] [ T500] hfs: detected unknown inode 15, running fsck.hfs is recommended.
