From 6e8ab72a812396996035a37e5ca4b3b99b5d214b Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 15 Jun 2018 12:28:16 -0400 Subject: ext4: clear i_data in ext4_inode_info when removing inline data When converting from an inode from storing the data in-line to a data block, ext4_destroy_inline_data_nolock() was only clearing the on-disk copy of the i_blocks[] array. It was not clearing copy of the i_blocks[] in ext4_inode_info, in i_data[], which is the copy actually used by ext4_map_blocks(). This didn't matter much if we are using extents, since the extents header would be invalid and thus the extents could would re-initialize the extents tree. But if we are using indirect blocks, the previous contents of the i_blocks array will be treated as block numbers, with potentially catastrophic results to the file system integrity and/or user data. This gets worse if the file system is using a 1k block size and s_first_data is zero, but even without this, the file system can get quite badly corrupted. This addresses CVE-2018-10881. https://bugzilla.kernel.org/show_bug.cgi?id=200015 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org --- fs/ext4/inline.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/ext4/inline.c') diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 44b4fcdc3755..d79115d8d716 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -437,6 +437,7 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle, memset((void *)ext4_raw_inode(&is.iloc)->i_block, 0, EXT4_MIN_INLINE_DATA_SIZE); + memset(ei->i_data, 0, EXT4_MIN_INLINE_DATA_SIZE); if (ext4_has_feature_extents(inode->i_sb)) { if (S_ISDIR(inode->i_mode) || -- cgit v1.2.3 From 8bc1379b82b8e809eef77a9fedbb75c6c297be19 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 16 Jun 2018 23:41:59 -0400 Subject: ext4: avoid running out of journal credits when appending to an inline file Use a separate journal transaction if it turns out that we need to convert an inline file to use an data block. Otherwise we could end up failing due to not having journal credits. This addresses CVE-2018-10883. https://bugzilla.kernel.org/show_bug.cgi?id=200071 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org --- fs/ext4/ext4.h | 3 --- fs/ext4/inline.c | 38 +------------------------------------- fs/ext4/xattr.c | 19 ++----------------- 3 files changed, 3 insertions(+), 57 deletions(-) (limited to 'fs/ext4/inline.c') diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 856b6a54d82b..859d6433dcc1 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -3013,9 +3013,6 @@ extern int ext4_inline_data_fiemap(struct inode *inode, struct iomap; extern int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap); -extern int ext4_try_to_evict_inline_data(handle_t *handle, - struct inode *inode, - int needed); extern int ext4_inline_data_truncate(struct inode *inode, int *has_inline); extern int ext4_convert_inline_data(struct inode *inode); diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index d79115d8d716..851bc552d849 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -887,11 +887,11 @@ retry_journal: flags |= AOP_FLAG_NOFS; if (ret == -ENOSPC) { + ext4_journal_stop(handle); ret = ext4_da_convert_inline_data_to_extent(mapping, inode, flags, fsdata); - ext4_journal_stop(handle); if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry_journal; @@ -1891,42 +1891,6 @@ out: return (error < 0 ? error : 0); } -/* - * Called during xattr set, and if we can sparse space 'needed', - * just create the extent tree evict the data to the outer block. - * - * We use jbd2 instead of page cache to move data to the 1st block - * so that the whole transaction can be committed as a whole and - * the data isn't lost because of the delayed page cache write. - */ -int ext4_try_to_evict_inline_data(handle_t *handle, - struct inode *inode, - int needed) -{ - int error; - struct ext4_xattr_entry *entry; - struct ext4_inode *raw_inode; - struct ext4_iloc iloc; - - error = ext4_get_inode_loc(inode, &iloc); - if (error) - return error; - - raw_inode = ext4_raw_inode(&iloc); - entry = (struct ext4_xattr_entry *)((void *)raw_inode + - EXT4_I(inode)->i_inline_off); - if (EXT4_XATTR_LEN(entry->e_name_len) + - EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)) < needed) { - error = -ENOSPC; - goto out; - } - - error = ext4_convert_inline_data_nolock(handle, inode, &iloc); -out: - brelse(iloc.bh); - return error; -} - int ext4_inline_data_truncate(struct inode *inode, int *has_inline) { handle_t *handle; diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 72377b77fbd7..723df14f4084 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -2212,23 +2212,8 @@ int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode, if (EXT4_I(inode)->i_extra_isize == 0) return -ENOSPC; error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */); - if (error) { - if (error == -ENOSPC && - ext4_has_inline_data(inode)) { - error = ext4_try_to_evict_inline_data(handle, inode, - EXT4_XATTR_LEN(strlen(i->name) + - EXT4_XATTR_SIZE(i->value_len))); - if (error) - return error; - error = ext4_xattr_ibody_find(inode, i, is); - if (error) - return error; - error = ext4_xattr_set_entry(i, s, handle, inode, - false /* is_block */); - } - if (error) - return error; - } + if (error) + return error; header = IHDR(inode, ext4_raw_inode(&is->iloc)); if (!IS_LAST_ENTRY(s->first)) { header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); -- cgit v1.2.3