From d325dc6eb763c10f591c239550b8c7e5466a5d09 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Tue, 4 Oct 2022 00:05:19 +0900 Subject: nilfs2: fix use-after-free bug of struct nilfs_root If the beginning of the inode bitmap area is corrupted on disk, an inode with the same inode number as the root inode can be allocated and fail soon after. In this case, the subsequent call to nilfs_clear_inode() on that bogus root inode will wrongly decrement the reference counter of struct nilfs_root, and this will erroneously free struct nilfs_root, causing kernel oopses. This fixes the problem by changing nilfs_new_inode() to skip reserved inode numbers while repairing the inode bitmap. Link: https://lkml.kernel.org/r/20221003150519.39789-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+b8c672b0e22615c80fe0@syzkaller.appspotmail.com Reported-by: Khalid Masum Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/inode.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 67f63cfeade5..b074144f6f83 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -328,6 +328,7 @@ struct inode *nilfs_new_inode(struct inode *dir, umode_t mode) struct inode *inode; struct nilfs_inode_info *ii; struct nilfs_root *root; + struct buffer_head *bh; int err = -ENOMEM; ino_t ino; @@ -343,11 +344,25 @@ struct inode *nilfs_new_inode(struct inode *dir, umode_t mode) ii->i_state = BIT(NILFS_I_NEW); ii->i_root = root; - err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh); + err = nilfs_ifile_create_inode(root->ifile, &ino, &bh); if (unlikely(err)) goto failed_ifile_create_inode; /* reference count of i_bh inherits from nilfs_mdt_read_block() */ + if (unlikely(ino < NILFS_USER_INO)) { + nilfs_warn(sb, + "inode bitmap is inconsistent for reserved inodes"); + do { + brelse(bh); + err = nilfs_ifile_create_inode(root->ifile, &ino, &bh); + if (unlikely(err)) + goto failed_ifile_create_inode; + } while (ino < NILFS_USER_INO); + + nilfs_info(sb, "repaired inode bitmap for reserved inodes"); + } + ii->i_bh = bh; + atomic64_inc(&root->inodes_count); inode_init_owner(&init_user_ns, inode, dir, mode); inode->i_ino = ino; -- cgit v1.2.3 From 21a87d88c2253350e115029f14fe2a10a7e6c856 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 2 Oct 2022 12:08:04 +0900 Subject: nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level() If the i_mode field in inode of metadata files is corrupted on disk, it can cause the initialization of bmap structure, which should have been called from nilfs_read_inode_common(), not to be called. This causes a lockdep warning followed by a NULL pointer dereference at nilfs_bmap_lookup_at_level(). This patch fixes these issues by adding a missing sanitiy check for the i_mode field of metadata file's inode. Link: https://lkml.kernel.org/r/20221002030804.29978-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Reported-by: syzbot+2b32eb36c1a825b7a74c@syzkaller.appspotmail.com Reported-by: Tetsuo Handa Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/inode.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index b074144f6f83..232dd7b6cca1 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -455,6 +455,8 @@ int nilfs_read_inode_common(struct inode *inode, inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec); inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec); + if (nilfs_is_metadata_file_inode(inode) && !S_ISREG(inode->i_mode)) + return -EIO; /* this inode is for metadata and corrupted */ if (inode->i_nlink == 0) return -ESTALE; /* this inode is deleted */ -- cgit v1.2.3 From d0d51a97063db4704a5ef6bc978dddab1636a306 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Fri, 7 Oct 2022 17:52:26 +0900 Subject: nilfs2: fix leak of nilfs_root in case of writer thread creation failure If nilfs_attach_log_writer() failed to create a log writer thread, it frees a data structure of the log writer without any cleanup. After commit e912a5b66837 ("nilfs2: use root object to get ifile"), this causes a leak of struct nilfs_root, which started to leak an ifile metadata inode and a kobject on that struct. In addition, if the kernel is booted with panic_on_warn, the above ifile metadata inode leak will cause the following panic when the nilfs2 kernel module is removed: kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when called from nilfs_destroy_cachep+0x16/0x3a [nilfs2] WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140 ... RIP: 0010:kmem_cache_destroy+0x138/0x140 Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48 ... Call Trace: ? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2] nilfs_destroy_cachep+0x16/0x3a [nilfs2] exit_nilfs_fs+0xa/0x1b [nilfs2] __x64_sys_delete_module+0x1d9/0x3a0 ? __sanitizer_cov_trace_pc+0x1a/0x50 ? syscall_trace_enter.isra.19+0x119/0x190 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd ... Kernel panic - not syncing: panic_on_warn set ... This patch fixes these issues by calling nilfs_detach_log_writer() cleanup function if spawning the log writer thread fails. Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com Fixes: e912a5b66837 ("nilfs2: use root object to get ifile") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton --- fs/nilfs2/segment.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 0afe0832c754..5276ab525f01 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -2786,10 +2786,9 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL); err = nilfs_segctor_start_thread(nilfs->ns_writer); - if (err) { - kfree(nilfs->ns_writer); - nilfs->ns_writer = NULL; - } + if (unlikely(err)) + nilfs_detach_log_writer(sb); + return err; } -- cgit v1.2.3