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| author | Ritesh Harjani <riteshh@linux.ibm.com> | 2020-05-05 17:43:14 +0200 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-05-19 15:03:37 -0400 |
| commit | 9f44eda19529b1c3eef50676dc54b8cd0aa86aa3 (patch) | |
| tree | 2640df9bf7bd8f4fa637cc91d8b70fb45c94a400 /fs/ext4/ext4.h | |
| parent | 0e698dfa282211e414076f9dc7e83c1c288314fd (diff) | |
| download | lwn-9f44eda19529b1c3eef50676dc54b8cd0aa86aa3.tar.gz lwn-9f44eda19529b1c3eef50676dc54b8cd0aa86aa3.zip | |
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
ext4 supports max number of logical blocks in a file to be 0xffffffff.
(This is since ext4_extent's ee_block is __le32).
This means that EXT4_MAX_LOGICAL_BLOCK should be 0xfffffffe (starting
from 0 logical offset). This patch fixes this.
The issue was seen when ext4 moved to iomap_fiemap API and when
overlayfs was mounted on top of ext4. Since overlayfs was missing
filemap_check_ranges(), so it could pass a arbitrary huge length which
lead to overflow of map.m_len logic.
This patch fixes that.
Fixes: d3b6f23f7167 ("ext4: move ext4_fiemap to use iomap framework")
Reported-by: syzbot+77fa5bdb65cc39711820@syzkaller.appspotmail.com
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200505154324.3226743-2-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 91eb4381cae5..ad2dbf6e4924 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -722,7 +722,7 @@ enum { #define EXT4_MAX_BLOCK_FILE_PHYS 0xFFFFFFFF /* Max logical block we can support */ -#define EXT4_MAX_LOGICAL_BLOCK 0xFFFFFFFF +#define EXT4_MAX_LOGICAL_BLOCK 0xFFFFFFFE /* * Structure of an inode on the disk |