From 909666933210eb145bc93426ce07f66bf3d1f798 Mon Sep 17 00:00:00 2001 From: Tahsin Erdogan Date: Wed, 21 Jun 2017 21:57:36 -0400 Subject: ext4: clean up ext4_xattr_inode_get() The input and output values of *size parameter are equal on successful return from ext4_xattr_inode_get(). On error return, the callers ignore the output value so there is no need to update it. Also check for NULL return from ext4_bread(). If the actual xattr inode size happens to be smaller than the expected size, ext4_bread() may return NULL which would indicate data corruption. Signed-off-by: Tahsin Erdogan Signed-off-by: Theodore Ts'o --- fs/ext4/xattr.c | 35 +++++++++++++---------------------- 1 file changed, 13 insertions(+), 22 deletions(-) (limited to 'fs/ext4/xattr.c') diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index f16a90824d44..61c67a04a7e1 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -278,37 +278,28 @@ ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, /* * Read the EA value from an inode. */ -static int -ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t *size) +static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size) { unsigned long block = 0; struct buffer_head *bh = NULL; - int blocksize; - size_t csize, ret_size = 0; - - if (*size == 0) - return 0; + int blocksize = ea_inode->i_sb->s_blocksize; + size_t csize, copied = 0; - blocksize = ea_inode->i_sb->s_blocksize; - - while (ret_size < *size) { - csize = (*size - ret_size) > blocksize ? blocksize : - *size - ret_size; + while (copied < size) { + csize = (size - copied) > blocksize ? blocksize : size - copied; bh = ext4_bread(NULL, ea_inode, block, 0); - if (IS_ERR(bh)) { - *size = ret_size; + if (IS_ERR(bh)) return PTR_ERR(bh); - } + if (!bh) + return -EFSCORRUPTED; + memcpy(buf, bh->b_data, csize); brelse(bh); buf += csize; block += 1; - ret_size += csize; + copied += csize; } - - *size = ret_size; - return 0; } @@ -360,7 +351,7 @@ error: */ static int ext4_xattr_inode_get(struct inode *inode, unsigned long ea_ino, void *buffer, - size_t *size) + size_t size) { struct inode *ea_inode; int ret; @@ -417,7 +408,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, if (entry->e_value_inum) { error = ext4_xattr_inode_get(inode, le32_to_cpu(entry->e_value_inum), - buffer, &size); + buffer, size); if (error) goto cleanup; } else { @@ -467,7 +458,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (entry->e_value_inum) { error = ext4_xattr_inode_get(inode, le32_to_cpu(entry->e_value_inum), - buffer, &size); + buffer, size); if (error) goto cleanup; } else { -- cgit v1.2.3