linux-stable.git/fs/ext4/ioctl.c, branch linux-6.2.y

ext4: zero i_disksize when initializing the bootloader inode

2023-03-17T07:57:48+00:00

commit f5361da1e60d54ec81346aee8e3d8baf1be0b762 upstream.

If the boot loader inode has never been used before, the
EXT4_IOC_SWAP_BOOT inode will initialize it, including setting the
i_size to 0.  However, if the "never before used" boot loader has a
non-zero i_size, then i_disksize will be non-zero, and the
inconsistency between i_size and i_disksize can trigger a kernel
warning:

 WARNING: CPU: 0 PID: 2580 at fs/ext4/file.c:319
 CPU: 0 PID: 2580 Comm: bb Not tainted 6.3.0-rc1-00004-g703695902cfa
 RIP: 0010:ext4_file_write_iter+0xbc7/0xd10
 Call Trace:
  vfs_write+0x3b1/0x5c0
  ksys_write+0x77/0x160
  __x64_sys_write+0x22/0x30
  do_syscall_64+0x39/0x80

Reproducer:
 1. create corrupted image and mount it:
       mke2fs -t ext4 /tmp/foo.img 200
       debugfs -wR "sif <5> size 25700" /tmp/foo.img
       mount -t ext4 /tmp/foo.img /mnt
       cd /mnt
       echo 123 > file
 2. Run the reproducer program:
       posix_memalign(&buf, 1024, 1024)
       fd = open("file", O_RDWR | O_DIRECT);
       ioctl(fd, EXT4_IOC_SWAP_BOOT);
       write(fd, buf, 1024);

Fix this by setting i_disksize as well as i_size to zero when
initiaizing the boot loader inode.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217159
Cc: stable@kernel.org
Signed-off-by: Zhihao Cheng 
Link: https://lore.kernel.org/r/20230308032643.641113-1-chengzhihao1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: initialize quota before expanding inode in setproject ioctl

2022-12-09T03:03:15+00:00

Make sure we initialize quotas before possibly expanding inode space
(and thus maybe needing to allocate external xattr block) in
ext4_ioctl_setproject(). This prevents not accounting the necessary
block allocation.

Signed-off-by: Jan Kara 
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20221207115937.26601-1-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: don't fail GETFSUUID when the caller provides a long buffer

2022-12-09T02:49:24+00:00

If userspace provides a longer UUID buffer than is required, we
shouldn't fail the call with EINVAL -- rather, we can fill the caller's
buffer with the bytes we /can/ fill, and update the length field to
reflect what we copied.  This doesn't break the UAPI since we're
enabling a case that currently fails, and so far Ted hasn't released a
version of e2fsprogs that uses the new ext4 ioctl.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Catherine Hoang 
Link: https://lore.kernel.org/r/166811139478.327006.13879198441587445544.stgit@magnolia
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: dont return EINVAL from GETFSUUID when reporting UUID length

2022-12-09T02:49:24+00:00

If userspace calls this ioctl with fsu_length (the length of the
fsuuid.fsu_uuid array) set to zero, ext4 copies the desired uuid length
out to userspace.  The kernel call returned a result from a valid input,
so the return value here should be zero, not EINVAL.

While we're at it, fix the copy_to_user call to make it clear that we're
only copying out fsu_len.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Catherine Hoang 
Link: https://lore.kernel.org/r/166811138914.327006.9241306894437166566.stgit@magnolia
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: fix bug_on in __es_tree_search caused by bad boot loader inode

2022-12-09T02:49:23+00:00

We got a issue as fllows:
==================================================================
 kernel BUG at fs/ext4/extents_status.c:203!
 invalid opcode: 0000 [#1] PREEMPT SMP
 CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349
 RIP: 0010:ext4_es_end.isra.0+0x34/0x42
 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203
 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff
 RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8
 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0
 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000
 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  
  __es_tree_search.isra.0+0x6d/0xf5
  ext4_es_cache_extent+0xfa/0x230
  ext4_cache_extents+0xd2/0x110
  ext4_find_extent+0x5d5/0x8c0
  ext4_ext_map_blocks+0x9c/0x1d30
  ext4_map_blocks+0x431/0xa50
  ext4_mpage_readpages+0x48e/0xe40
  ext4_readahead+0x47/0x50
  read_pages+0x82/0x530
  page_cache_ra_unbounded+0x199/0x2a0
  do_page_cache_ra+0x47/0x70
  page_cache_ra_order+0x242/0x400
  ondemand_readahead+0x1e8/0x4b0
  page_cache_sync_ra+0xf4/0x110
  filemap_get_pages+0x131/0xb20
  filemap_read+0xda/0x4b0
  generic_file_read_iter+0x13a/0x250
  ext4_file_read_iter+0x59/0x1d0
  vfs_read+0x28f/0x460
  ksys_read+0x73/0x160
  __x64_sys_read+0x1e/0x30
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  
==================================================================

In the above issue, ioctl invokes the swap_inode_boot_loader function to
swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and
disordered extents, and i_nlink is set to 1. The extents check for inode in
the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO.
While links_count is set to 1, the extents are not initialized in
swap_inode_boot_loader. After the ioctl command is executed successfully,
the extents are swapped to inode<12>, in this case, run the `cat` command
to view inode<12>. And Bug_ON is triggered due to the incorrect extents.

When the boot loader inode is not initialized, its imode can be one of the
following:
1) the imode is a bad type, which is marked as bad_inode in ext4_iget and
   set to S_IFREG.
2) the imode is good type but not S_IFREG.
3) the imode is S_IFREG.

The BUG_ON may be triggered by bypassing the check in cases 1 and 2.
Therefore, when the boot loader inode is bad_inode or its imode is not
S_IFREG, initialize the inode to avoid triggering the BUG.

Signed-off-by: Baokun Li 
Reviewed-by: Jason Yan 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20221026042310.3839669-5-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode

2022-12-09T02:49:23+00:00

There are many places that will get unhappy (and crash) when ext4_iget()
returns a bad inode. However, if iget the boot loader inode, allows a bad
inode to be returned, because the inode may not be initialized. This
mechanism can be used to bypass some checks and cause panic. To solve this
problem, we add a special iget flag EXT4_IGET_BAD. Only with this flag
we'd be returning bad inode from ext4_iget(), otherwise we always return
the error code if the inode is bad inode.(suggested by Jan Kara)

Signed-off-by: Baokun Li 
Reviewed-by: Jason Yan 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20221026042310.3839669-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2022-11-06T18:30:29+00:00

Pull ext4 fixes from Ted Ts'o:
 "Fix a number of bugs, including some regressions, the most serious of
  which was one which would cause online resizes to fail with file
  systems with metadata checksums enabled.

  Also fix a warning caused by the newly added fortify string checker,
  plus some bugs that were found using fuzzed file systems"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix fortify warning in fs/ext4/fast_commit.c:1551
  ext4: fix wrong return err in ext4_load_and_init_journal()
  ext4: fix warning in 'ext4_da_release_space'
  ext4: fix BUG_ON() when directory entry has invalid rec_len
  ext4: update the backup superblock's at the end of the online resize

ext4: update the backup superblock's at the end of the online resize

2022-10-28T03:21:40+00:00

When expanding a file system using online resize, various fields in
the superblock (e.g., s_blocks_count, s_inodes_count, etc.) change.
To update the backup superblocks, the online resize uses the function
update_backups() in fs/ext4/resize.c.  This function was not updating
the checksum field in the backup superblocks.  This wasn't a big deal
previously, because e2fsck didn't care about the checksum field in the
backup superblock.  (And indeed, update_backups() goes all the way
back to the ext3 days, well before we had support for metadata
checksums.)

However, there is an alternate, more general way of updating
superblock fields, ext4_update_primary_sb() in fs/ext4/ioctl.c.  This
function does check the checksum of the backup superblock, and if it
doesn't match will mark the file system as corrupted.  That was
clearly not the intent, so avoid to aborting the resize when a bad
superblock is found.

In addition, teach update_backups() to properly update the checksum in
the backup superblocks.  We will eventually want to unify
updapte_backups() with the infrasture in ext4_update_primary_sb(), but
that's for another day.

Note: The problem has been around for a while; it just didn't really
matter until ext4_update_primary_sb() was added by commit bbc605cdb1e1
("ext4: implement support for get/set fs label").  And it became
trivially easy to reproduce after commit 827891a38acc ("ext4: update
the s_overhead_clusters in the backup sb's when resizing") in v6.0.

Cc: stable@kernel.org # 5.17+
Fixes: bbc605cdb1e1 ("ext4: implement support for get/set fs label")
Signed-off-by: Theodore Ts'o

treewide: use get_random_u32() when possible

2022-10-11T23:42:58+00:00

The prandom_u32() function has been a deprecated inline wrapper around
get_random_u32() for several releases now, and compiles down to the
exact same code. Replace the deprecated wrapper with a direct call to
the real function. The same also applies to get_random_int(), which is
just a wrapper around get_random_u32(). This was done as a basic find
and replace.

Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kees Cook 
Reviewed-by: Yury Norov 
Reviewed-by: Jan Kara  # for ext4
Acked-by: Toke Høiland-Jørgensen  # for sch_cake
Acked-by: Chuck Lever  # for nfsd
Acked-by: Jakub Kicinski 
Acked-by: Mika Westerberg  # for thunderbolt
Acked-by: Darrick J. Wong  # for xfs
Acked-by: Helge Deller  # for parisc
Acked-by: Heiko Carstens  # for s390
Signed-off-by: Jason A. Donenfeld

ext4: remove redundant checking in ext4_ioctl_checkpoint

2022-10-01T03:46:54+00:00

It is already checked after comment "check for invalid bits set",
so let's remove this one.

Signed-off-by: Guoqing Jiang 
Link: https://lore.kernel.org/r/20220918115219.12407-1-guoqing.jiang@linux.dev
Signed-off-by: Theodore Ts'o