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author | Theodore Ts'o <tytso@mit.edu> | 2016-03-22 20:13:15 (GMT) |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2016-03-22 20:13:15 (GMT) |
commit | 9e92f48c34eb2b9af9d12f892e2fe1fce5e8ce35 (patch) | |
tree | fd069c88e42791d7ed0ab087bc5389b98b574458 /fs/ext4 | |
parent | 243d50678583100855862bc084b8b307eea67f68 (diff) | |
download | linux-9e92f48c34eb2b9af9d12f892e2fe1fce5e8ce35.tar.xz |
ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()
We aren't checking to see if the in-inode extended attribute is
corrupted before we try to expand the inode's extra isize fields.
This can lead to potential crashes caused by the BUG_ON() check in
ext4_xattr_shift_entries().
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r-- | fs/ext4/xattr.c | 32 |
1 files changed, 28 insertions, 4 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 0441e05..e79bd32 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -230,6 +230,27 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh) return error; } +static int +__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, + void *end, const char *function, unsigned int line) +{ + struct ext4_xattr_entry *entry = IFIRST(header); + int error = -EFSCORRUPTED; + + if (((void *) header >= end) || + (header->h_magic != le32_to_cpu(EXT4_XATTR_MAGIC))) + goto errout; + error = ext4_xattr_check_names(entry, end, entry); +errout: + if (error) + __ext4_error_inode(inode, function, line, 0, + "corrupted in-inode xattr"); + return error; +} + +#define xattr_check_inode(inode, header, end) \ + __xattr_check_inode((inode), (header), (end), __func__, __LINE__) + static inline int ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size) { @@ -341,7 +362,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, header = IHDR(inode, raw_inode); entry = IFIRST(header); end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(entry, end, entry); + error = xattr_check_inode(inode, header, end); if (error) goto cleanup; error = ext4_xattr_find_entry(&entry, name_index, name, @@ -477,7 +498,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header)); + error = xattr_check_inode(inode, header, end); if (error) goto cleanup; error = ext4_xattr_list_entries(dentry, IFIRST(header), @@ -1040,8 +1061,7 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, is->s.here = is->s.first; is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { - error = ext4_xattr_check_names(IFIRST(header), is->s.end, - IFIRST(header)); + error = xattr_check_inode(inode, header, is->s.end); if (error) return error; /* Find the named attribute. */ @@ -1356,6 +1376,10 @@ retry: last = entry; total_ino = sizeof(struct ext4_xattr_ibody_header); + error = xattr_check_inode(inode, header, end); + if (error) + goto cleanup; + free = ext4_xattr_free_space(last, &min_offs, base, &total_ino); if (free >= new_extra_isize) { entry = IFIRST(header); |