Commit 8a363970 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: avoid declaring fs inconsistent due to invalid file handles 



If we receive a file handle, either from NFS or open_by_handle_at(2),
and it points at an inode which has not been initialized, and the file
system has metadata checksums enabled, we shouldn't try to get the
inode, discover the checksum is invalid, and then declare the file
system as being inconsistent.

This can be reproduced by creating a test file system via "mke2fs -t
ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that
directory, and then running the following program.

#define _GNU_SOURCE
#include <fcntl.h>

struct handle {
	struct file_handle fh;
	unsigned char fid[MAX_HANDLE_SZ];
};

int main(int argc, char **argv)
{
	struct handle h = {{8, 1 }, { 12, }};

	open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY);
	return 0;
}

Google-Bug-Id: 120690101
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent a805622a

fs/ext4/ext4.h

+13 −2
Original line number Diff line number Diff line
@@ -2454,8 +2454,19 @@ int do_journal_get_write_access(handle_t *handle, 
#define FALL_BACK_TO_NONDELALLOC 1

#define CONVERT_INLINE_DATA	 2



extern struct inode *ext4_iget(struct super_block *, unsigned long);

extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);

typedef enum {

	EXT4_IGET_NORMAL =	0,

	EXT4_IGET_SPECIAL =	0x0001, /* OK to iget a system inode */

	EXT4_IGET_HANDLE = 	0x0002	/* Inode # is from a handle */

} ext4_iget_flags;



extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,

				 ext4_iget_flags flags, const char *function,

				 unsigned int line);



#define ext4_iget(sb, ino, flags) \

	__ext4_iget((sb), (ino), (flags), __func__, __LINE__)



extern int  ext4_write_inode(struct inode *, struct writeback_control *);

extern int  ext4_setattr(struct dentry *, struct iattr *);

extern int  ext4_getattr(const struct path *, struct kstat *, u32, unsigned int);

fs/ext4/ialloc.c

+1 −1
Original line number Diff line number Diff line
@@ -1225,7 +1225,7 @@ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) 
	if (!ext4_test_bit(bit, bitmap_bh->b_data))

		goto bad_orphan;



	inode = ext4_iget(sb, ino);

	inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL);

	if (IS_ERR(inode)) {

		err = PTR_ERR(inode);

		ext4_error(sb, "couldn't read orphan inode %lu (err %d)",

fs/ext4/inode.c

+37 −17
Original line number Diff line number Diff line
@@ -4817,7 +4817,9 @@ static inline u64 ext4_inode_peek_iversion(const struct inode *inode) 
		return inode_peek_iversion(inode);

}



struct inode *ext4_iget(struct super_block *sb, unsigned long ino)

struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,

			  ext4_iget_flags flags, const char *function,

			  unsigned int line)

{

	struct ext4_iloc iloc;

	struct ext4_inode *raw_inode;
@@ -4831,6 +4833,18 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	gid_t i_gid;

	projid_t i_projid;



	if (((flags & EXT4_IGET_NORMAL) &&

	     (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)) ||

	    (ino < EXT4_ROOT_INO) ||

	    (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) {

		if (flags & EXT4_IGET_HANDLE)

			return ERR_PTR(-ESTALE);

		__ext4_error(sb, function, line,

			     "inode #%lu: comm %s: iget: illegal inode #",

			     ino, current->comm);

		return ERR_PTR(-EFSCORRUPTED);

	}



	inode = iget_locked(sb, ino);

	if (!inode)

		return ERR_PTR(-ENOMEM);
@@ -4846,18 +4860,26 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	raw_inode = ext4_raw_inode(&iloc);



	if ((ino == EXT4_ROOT_INO) && (raw_inode->i_links_count == 0)) {

		EXT4_ERROR_INODE(inode, "root inode unallocated");

		ext4_error_inode(inode, function, line, 0,

				 "iget: root inode unallocated");

		ret = -EFSCORRUPTED;

		goto bad_inode;

	}



	if ((flags & EXT4_IGET_HANDLE) &&

	    (raw_inode->i_links_count == 0) && (raw_inode->i_mode == 0)) {

		ret = -ESTALE;

		goto bad_inode;

	}



	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {

		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);

		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >

			EXT4_INODE_SIZE(inode->i_sb) ||

		    (ei->i_extra_isize & 3)) {

			EXT4_ERROR_INODE(inode,

					 "bad extra_isize %u (inode size %u)",

			ext4_error_inode(inode, function, line, 0,

					 "iget: bad extra_isize %u "

					 "(inode size %u)",

					 ei->i_extra_isize,

					 EXT4_INODE_SIZE(inode->i_sb));

			ret = -EFSCORRUPTED;
@@ -4879,7 +4901,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	}



	if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {

		EXT4_ERROR_INODE(inode, "checksum invalid");

		ext4_error_inode(inode, function, line, 0,

				 "iget: checksum invalid");

		ret = -EFSBADCRC;

		goto bad_inode;

	}
@@ -4936,7 +4959,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
			((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;

	inode->i_size = ext4_isize(sb, raw_inode);

	if ((size = i_size_read(inode)) < 0) {

		EXT4_ERROR_INODE(inode, "bad i_size value: %lld", size);

		ext4_error_inode(inode, function, line, 0,

				 "iget: bad i_size value: %lld", size);

		ret = -EFSCORRUPTED;

		goto bad_inode;

	}
@@ -5012,7 +5036,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	ret = 0;

	if (ei->i_file_acl &&

	    !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {

		EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",

		ext4_error_inode(inode, function, line, 0,

				 "iget: bad extended attribute block %llu",

				 ei->i_file_acl);

		ret = -EFSCORRUPTED;

		goto bad_inode;
@@ -5040,8 +5065,9 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	} else if (S_ISLNK(inode->i_mode)) {

		/* VFS does not allow setting these so must be corruption */

		if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) {

			EXT4_ERROR_INODE(inode,

			  "immutable or append flags not allowed on symlinks");

			ext4_error_inode(inode, function, line, 0,

					 "iget: immutable or append flags "

					 "not allowed on symlinks");

			ret = -EFSCORRUPTED;

			goto bad_inode;

		}
@@ -5071,7 +5097,8 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
		make_bad_inode(inode);

	} else {

		ret = -EFSCORRUPTED;

		EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);

		ext4_error_inode(inode, function, line, 0,

				 "iget: bogus i_mode (%o)", inode->i_mode);

		goto bad_inode;

	}

	brelse(iloc.bh);
@@ -5085,13 +5112,6 @@ bad_inode: 
	return ERR_PTR(ret);

}



struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)

{

	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)

		return ERR_PTR(-EFSCORRUPTED);

	return ext4_iget(sb, ino);

}



static int ext4_inode_blocks_set(handle_t *handle,

				struct ext4_inode *raw_inode,

				struct ext4_inode_info *ei)

fs/ext4/ioctl.c

+1 −1
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ static long swap_inode_boot_loader(struct super_block *sb, 
	    !inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))

		return -EPERM;



	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);

	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, EXT4_IGET_SPECIAL);

	if (IS_ERR(inode_bl))

		return PTR_ERR(inode_bl);

	ei_bl = EXT4_I(inode_bl);

fs/ext4/namei.c

+2 −2
Original line number Diff line number Diff line
@@ -1571,7 +1571,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi 
					 dentry);

			return ERR_PTR(-EFSCORRUPTED);

		}

		inode = ext4_iget_normal(dir->i_sb, ino);

		inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL);

		if (inode == ERR_PTR(-ESTALE)) {

			EXT4_ERROR_INODE(dir,

					 "deleted inode referenced: %u",
@@ -1613,7 +1613,7 @@ struct dentry *ext4_get_parent(struct dentry *child) 
		return ERR_PTR(-EFSCORRUPTED);

	}



	return d_obtain_alias(ext4_iget_normal(child->d_sb, ino));

	return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL));

}



/*

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