From nobody Mon Dec 1 23:34:57 2025 Received: from ewsoutbound.kpnmail.nl (ewsoutbound.kpnmail.nl [195.121.94.170]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BC362EBBB4 for ; Tue, 25 Nov 2025 21:13:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.121.94.170 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764105224; cv=none; b=jNzKC9c1K+MKtcUOQYfhVGe5pko40BRLF5HUb9S2UJn9eX/VntrHor6evyFiMxJBlcWVgzsNzSeYw/3TgRH1wzWrvSPNQKVZgpQKqvsLUi5XfsDE0W92cI9D2Bq3vb/5gYIqjyLZuxGMsAdHiCRJAcwvipPXuBIpuOWCfm37DaY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764105224; c=relaxed/simple; bh=RuMV7T1lsRwZvgKwUG2IbRElBI4SLUyhl8aWvBZqu3Y=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=sZKFh0a1Fu2RvJwahPdQn0dPI00ygEn8GG5wkE9RhCxFUMkFbLOQCyBWSNpMFCn9pS76qfXk0u+1sM3hWmgfIibonFnrwxs0nKAyDnUszPYanhOjNhl07XnKOFBPxSbMGCPXslexgETvSL1FTfByArAiqU1BYdnOZ30efSv42j8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xs4all.nl; spf=pass smtp.mailfrom=xs4all.nl; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b=uPZsoVgR; arc=none smtp.client-ip=195.121.94.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=xs4all.nl Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=xs4all.nl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b="uPZsoVgR" X-KPN-MessageId: e35cc18a-ca43-11f0-9c78-005056ab378f Received: from smtp.kpnmail.nl (unknown [10.31.155.39]) by ewsoutbound.so.kpn.org (Halon) with ESMTPS id e35cc18a-ca43-11f0-9c78-005056ab378f; Tue, 25 Nov 2025 22:15:37 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=xs4all01; h=content-type:mime-version:message-id:date:subject:to:from; bh=XvYQBhbB2su/NQDIRlNnreV4ebeiTeHkR0s2XuDIkOk=; b=uPZsoVgRTJnmRJCaRwbe+Y9aTj2R9IFPnuamyAfFT2J1q+XepJYZQyiOpWlmySVVncYHn9B5A9lsa MFn3MVekC7P3YCMANa72MiS+CDHHSjOaJjrjTe1nlxhRArOh6h4dmsczGLedA6yXbiIbKD8O4xU6Dh hayIbgDvGE8+gUysF+VohRbheIq954hHNiK4tzVOVChboFcXQU6qd/jzo8z6QPb6uIkEM6MjgWNsQJ A4f8ohlPndIYNdDkB+SNZXeNptt8iZ+7WFcz9Bl+YlzLL5SDV17ckz/E2sVqwVCJ9udk5smstngngI VbYm5PKr8BQrTE8YHsYpFeEEgAEtU8g== X-KPN-MID: 33|CmZ7cAW9IEe93QMPHVya3B4l2UXhHnXN4tIGUe2SaKeuQPoQLMvoC1zQmeV0IGP rI0OeKv33eQ9D+8UKGr2pAlIis4JZcrbMtPOoXLPPWfU= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|pDUMv9Zp4PjEgMrFrDc4ai3FlYsQQjnaPsV0rDDZERK0YJ3YFo/FnWepsasqt8x Y/6Km58oRULjruKxEhGRW9w== Received: from daedalus.home (unknown [178.228.24.129]) by smtp.xs4all.nl (Halon) with ESMTPSA id 9317f1aa-ca43-11f0-800a-005056ab7447; Tue, 25 Nov 2025 22:13:33 +0100 (CET) From: Jori Koolstra To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: slava@dubeyko.com, glaubitz@physik.fu-berlin.de, frank.li@vivo.com, skhan@linuxfoundation.org, Jori Koolstra , syzbot+17cc9bb6d8d69b4139f0@syzkaller.appspotmail.com Subject: [PATCH v2] hfs: replace BUG_ONs with error handling Date: Tue, 25 Nov 2025 22:13:27 +0100 Message-ID: <20251125211329.2835801-1-jkoolstra@xs4all.nl> X-Mailer: git-send-email 2.51.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable In a06ec283e125 next_id, folder_count, and file_count in the super block info were expanded to 64 bits, and BUG_ONs were added to detect overflow. This triggered an error reported by syzbot: if the MDB is corrupted, the BUG_ON is triggered. This patch replaces this mechanism with proper error handling and resolves the syzbot reported bug. Singed-off-by: Jori Koolstra Reported-by: syzbot+17cc9bb6d8d69b4139f0@syzkaller.appspotmail.com Closes: https://syzbot.org/bug?extid=3D17cc9bb6d8d69b4139f0 Signed-off-by: Jori Koolstra --- fs/hfs/dir.c | 12 ++++++------ fs/hfs/hfs.h | 3 +++ fs/hfs/hfs_fs.h | 2 +- fs/hfs/inode.c | 40 ++++++++++++++++++++++++++++++++-------- fs/hfs/mdb.c | 15 ++++++++++++--- 5 files changed, 54 insertions(+), 18 deletions(-) diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c index 86a6b317b474..03881a91f869 100644 --- a/fs/hfs/dir.c +++ b/fs/hfs/dir.c @@ -196,8 +196,8 @@ static int hfs_create(struct mnt_idmap *idmap, struct i= node *dir, int res; =20 inode =3D hfs_new_inode(dir, &dentry->d_name, mode); - if (!inode) - return -ENOMEM; + if (IS_ERR(inode)) + return PTR_ERR(inode); =20 res =3D hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode); if (res) { @@ -226,8 +226,8 @@ static struct dentry *hfs_mkdir(struct mnt_idmap *idmap= , struct inode *dir, int res; =20 inode =3D hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode); - if (!inode) - return ERR_PTR(-ENOMEM); + if (IS_ERR(inode)) + return ERR_CAST(inode); =20 res =3D hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode); if (res) { @@ -264,9 +264,9 @@ static int hfs_remove(struct inode *dir, struct dentry = *dentry) return res; clear_nlink(inode); inode_set_ctime_current(inode); - hfs_delete_inode(inode); + res =3D hfs_delete_inode(inode); mark_inode_dirty(inode); - return 0; + return res; } =20 /* diff --git a/fs/hfs/hfs.h b/fs/hfs/hfs.h index 6f194d0768b6..4b4797ef4e50 100644 --- a/fs/hfs/hfs.h +++ b/fs/hfs/hfs.h @@ -287,3 +287,6 @@ struct hfs_readdir_data { }; =20 #endif + + +#define EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */ diff --git a/fs/hfs/hfs_fs.h b/fs/hfs/hfs_fs.h index fff149af89da..21dfdde71b14 100644 --- a/fs/hfs/hfs_fs.h +++ b/fs/hfs/hfs_fs.h @@ -182,7 +182,7 @@ extern void hfs_inode_read_fork(struct inode *inode, st= ruct hfs_extent *ext, __be32 log_size, __be32 phys_size, u32 clump_size); extern struct inode *hfs_iget(struct super_block *, struct hfs_cat_key *, = hfs_cat_rec *); extern void hfs_evict_inode(struct inode *); -extern void hfs_delete_inode(struct inode *); +extern int hfs_delete_inode(struct inode *); =20 /* attr.c */ extern const struct xattr_handler * const hfs_xattr_handlers[]; diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c index 9cd449913dc8..ce27d49c41e4 100644 --- a/fs/hfs/inode.c +++ b/fs/hfs/inode.c @@ -186,16 +186,22 @@ struct inode *hfs_new_inode(struct inode *dir, const = struct qstr *name, umode_t s64 next_id; s64 file_count; s64 folder_count; + int err =3D -ENOMEM; =20 if (!inode) - return NULL; + goto out_err; + + err =3D -EFSCORRUPTED; =20 mutex_init(&HFS_I(inode)->extents_lock); INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list); spin_lock_init(&HFS_I(inode)->open_dir_lock); hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, na= me); next_id =3D atomic64_inc_return(&HFS_SB(sb)->next_id); - BUG_ON(next_id > U32_MAX); + if (next_id > U32_MAX) { + pr_err("next CNID exceeds limit =E2=80=94 filesystem corrupted. It is re= commended to run fsck\n"); + goto out_discard; + } inode->i_ino =3D (u32)next_id; inode->i_mode =3D mode; inode->i_uid =3D current_fsuid(); @@ -209,7 +215,10 @@ struct inode *hfs_new_inode(struct inode *dir, const s= truct qstr *name, umode_t if (S_ISDIR(mode)) { inode->i_size =3D 2; folder_count =3D atomic64_inc_return(&HFS_SB(sb)->folder_count); - BUG_ON(folder_count > U32_MAX); + if (folder_count > U32_MAX) { + pr_err("folder count exceeds limit =E2=80=94 filesystem corrupted. It i= s recommended to run fsck\n"); + goto out_discard; + } if (dir->i_ino =3D=3D HFS_ROOT_CNID) HFS_SB(sb)->root_dirs++; inode->i_op =3D &hfs_dir_inode_operations; @@ -219,7 +228,10 @@ struct inode *hfs_new_inode(struct inode *dir, const s= truct qstr *name, umode_t } else if (S_ISREG(mode)) { HFS_I(inode)->clump_blocks =3D HFS_SB(sb)->clumpablks; file_count =3D atomic64_inc_return(&HFS_SB(sb)->file_count); - BUG_ON(file_count > U32_MAX); + if (file_count > U32_MAX) { + pr_err("file count exceeds limit =E2=80=94 filesystem corrupted. It is = recommended to run fsck\n"); + goto out_discard; + } if (dir->i_ino =3D=3D HFS_ROOT_CNID) HFS_SB(sb)->root_files++; inode->i_op =3D &hfs_file_inode_operations; @@ -243,24 +255,35 @@ struct inode *hfs_new_inode(struct inode *dir, const = struct qstr *name, umode_t hfs_mark_mdb_dirty(sb); =20 return inode; + + out_discard: + iput(inode);=09 + out_err: + return ERR_PTR(err);=20 } =20 -void hfs_delete_inode(struct inode *inode) +int hfs_delete_inode(struct inode *inode) { struct super_block *sb =3D inode->i_sb; =20 hfs_dbg("ino %lu\n", inode->i_ino); if (S_ISDIR(inode->i_mode)) { - BUG_ON(atomic64_read(&HFS_SB(sb)->folder_count) > U32_MAX); + if (atomic64_read(&HFS_SB(sb)->folder_count) > U32_MAX) { + pr_err("folder count exceeds limit =E2=80=94 filesystem corrupted. It i= s recommended to run fsck\n"); + return -EFSCORRUPTED; + } atomic64_dec(&HFS_SB(sb)->folder_count); if (HFS_I(inode)->cat_key.ParID =3D=3D cpu_to_be32(HFS_ROOT_CNID)) HFS_SB(sb)->root_dirs--; set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags); hfs_mark_mdb_dirty(sb); - return; + return 0; } =20 - BUG_ON(atomic64_read(&HFS_SB(sb)->file_count) > U32_MAX); + if (atomic64_read(&HFS_SB(sb)->file_count) > U32_MAX) { + pr_err("file count exceeds limit =E2=80=94 filesystem corrupted. It is r= ecommended to run fsck\n"); + return -EFSCORRUPTED; + } atomic64_dec(&HFS_SB(sb)->file_count); if (HFS_I(inode)->cat_key.ParID =3D=3D cpu_to_be32(HFS_ROOT_CNID)) HFS_SB(sb)->root_files--; @@ -272,6 +295,7 @@ void hfs_delete_inode(struct inode *inode) } set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags); hfs_mark_mdb_dirty(sb); + return 0; } =20 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext, diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c index 53f3fae60217..45b690ab4ba5 100644 --- a/fs/hfs/mdb.c +++ b/fs/hfs/mdb.c @@ -273,15 +273,24 @@ void hfs_mdb_commit(struct super_block *sb) /* These parameters may have been modified, so write them back */ mdb->drLsMod =3D hfs_mtime(); mdb->drFreeBks =3D cpu_to_be16(HFS_SB(sb)->free_ablocks); - BUG_ON(atomic64_read(&HFS_SB(sb)->next_id) > U32_MAX); + if (atomic64_read(&HFS_SB(sb)->next_id) > U32_MAX) { + pr_err("next CNID exceeds limit =E2=80=94 filesystem corrupted. It is r= ecommended to run fsck\n"); + return; + } mdb->drNxtCNID =3D cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->next_id)); mdb->drNmFls =3D cpu_to_be16(HFS_SB(sb)->root_files); mdb->drNmRtDirs =3D cpu_to_be16(HFS_SB(sb)->root_dirs); - BUG_ON(atomic64_read(&HFS_SB(sb)->file_count) > U32_MAX); + if (atomic64_read(&HFS_SB(sb)->file_count) > U32_MAX) { + pr_err("file count exceeds limit =E2=80=94 filesystem corrupted. It is = recommended to run fsck\n"); + return; + } mdb->drFilCnt =3D cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->file_count)); - BUG_ON(atomic64_read(&HFS_SB(sb)->folder_count) > U32_MAX); + if (atomic64_read(&HFS_SB(sb)->folder_count) > U32_MAX) { + pr_err("folder count exceeds limit =E2=80=94 filesystem corrupted. It i= s recommended to run fsck\n"); + return; + } mdb->drDirCnt =3D cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->folder_count)); =20 --=20 2.51.2