| Message ID | e31dbabc453d1f227371bed6e0cc2f3493b4955f.1587555962.git.riteshh@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | ext4/overlayfs: fiemap related fixes | expand |
On Thu 23-04-20 16:17:53, Ritesh Harjani wrote: > 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> The patch looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/ext4.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > 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 > -- > 2.21.0 >
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
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> --- fs/ext4/ext4.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)