linux-stable.git/fs/nilfs2, branch linux-6.2.y

nilfs2: fix infinite loop in nilfs_mdt_get_block()

2023-05-11T14:11:33+00:00

commit a6a491c048882e7e424d407d32cba0b52d9ef2bf upstream.

If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code as
-ENOENT, meaning the block does not exist in the metadata file.

This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.

In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.

Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block
address translation failures with -ENOENT as metadata corruption instead
of returning the error code.

Link: https://lkml.kernel.org/r/20230430193046.6769-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com
  Link: https://syzkaller.appspot.com/bug?extid=221d75710bde87fa0e97
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: do not write dirty data after degenerating to read-only

2023-05-11T14:11:33+00:00

commit 28a65b49eb53e172d23567005465019658bfdb4d upstream.

According to syzbot's report, mark_buffer_dirty() called from
nilfs_segctor_do_construct() outputs a warning with some patterns after
nilfs2 detects metadata corruption and degrades to read-only mode.

After such read-only degeneration, page cache data may be cleared through
nilfs_clear_dirty_page() which may also clear the uptodate flag for their
buffer heads.  However, even after the degeneration, log writes are still
performed by unmount processing etc., which causes mark_buffer_dirty() to
be called for buffer heads without the "uptodate" flag and causes the
warning.

Since any writes should not be done to a read-only file system in the
first place, this fixes the warning in mark_buffer_dirty() by letting
nilfs_segctor_do_construct() abort early if in read-only mode.

This also changes the retry check of nilfs_segctor_write_out() to avoid
unnecessary log write retries if it detects -EROFS that
nilfs_segctor_do_construct() returned.

Link: https://lkml.kernel.org/r/20230427011526.13457-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Reported-by: syzbot+2af3bc9585be7f23f290@syzkaller.appspotmail.com
  Link: https://syzkaller.appspot.com/bug?extid=2af3bc9585be7f23f290
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: initialize unused bytes in segment summary blocks

2023-04-26T12:30:04+00:00

commit ef832747a82dfbc22a3702219cc716f449b24e4a upstream.

Syzbot still reports uninit-value in nilfs_add_checksums_on_logs() for
KMSAN enabled kernels after applying commit 7397031622e0 ("nilfs2:
initialize "struct nilfs_binfo_dat"->bi_pad field").

This is because the unused bytes at the end of each block in segment
summaries are not initialized.  So this fixes the issue by padding the
unused bytes with null bytes.

Link: https://lkml.kernel.org/r/20230417173513.12598-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Reported-by: syzbot+048585f3f4227bb2b49b@syzkaller.appspotmail.com
  Link: https://syzkaller.appspot.com/bug?extid=048585f3f4227bb2b49b
Cc: Alexander Potapenko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix sysfs interface lifetime

2023-04-13T15:02:46+00:00

commit 42560f9c92cc43dce75dbf06cc0d840dced39b12 upstream.

The current nilfs2 sysfs support has issues with the timing of creation
and deletion of sysfs entries, potentially leading to null pointer
dereferences, use-after-free, and lockdep warnings.

Some of the sysfs attributes for nilfs2 per-filesystem instance refer to
metadata file "cpfile", "sufile", or "dat", but
nilfs_sysfs_create_device_group that creates those attributes is executed
before the inodes for these metadata files are loaded, and
nilfs_sysfs_delete_device_group which deletes these sysfs entries is
called after releasing their metadata file inodes.

Therefore, access to some of these sysfs attributes may occur outside of
the lifetime of these metadata files, resulting in inode NULL pointer
dereferences or use-after-free.

In addition, the call to nilfs_sysfs_create_device_group() is made during
the locking period of the semaphore "ns_sem" of nilfs object, so the
shrinker call caused by the memory allocation for the sysfs entries, may
derive lock dependencies "ns_sem" -> (shrinker) -> "locks acquired in
nilfs_evict_inode()".

Since nilfs2 may acquire "ns_sem" deep in the call stack holding other
locks via its error handler __nilfs_error(), this causes lockdep to report
circular locking.  This is a false positive and no circular locking
actually occurs as no inodes exist yet when
nilfs_sysfs_create_device_group() is called.  Fortunately, the lockdep
warnings can be resolved by simply moving the call to
nilfs_sysfs_create_device_group() out of "ns_sem".

This fixes these sysfs issues by revising where the device's sysfs
interface is created/deleted and keeping its lifetime within the lifetime
of the metadata files above.

Link: https://lkml.kernel.org/r/20230330205515.6167-1-konishi.ryusuke@gmail.com
Fixes: dd70edbde262 ("nilfs2: integrate sysfs support into driver")
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+979fa7f9c0d086fdc282@syzkaller.appspotmail.com
  Link: https://lkml.kernel.org/r/0000000000003414b505f7885f7e@google.com
Reported-by: syzbot+5b7d542076d9bddc3c6a@syzkaller.appspotmail.com
  Link: https://lkml.kernel.org/r/0000000000006ac86605f5f44eb9@google.com
Cc: Viacheslav Dubeyko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()

2023-04-13T15:02:46+00:00

commit 6be49d100c22ffea3287a4b19d7639d259888e33 upstream.

The finalization of nilfs_segctor_thread() can race with
nilfs_segctor_kill_thread() which terminates that thread, potentially
causing a use-after-free BUG as KASAN detected.

At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member
of "struct nilfs_sc_info" to indicate the thread has finished, and then
notifies nilfs_segctor_kill_thread() of this using waitqueue
"sc_wait_task" on the struct nilfs_sc_info.

However, here, immediately after the NULL assignment to "sc_task", it is
possible that nilfs_segctor_kill_thread() will detect it and return to
continue the deallocation, freeing the nilfs_sc_info structure before the
thread does the notification.

This fixes the issue by protecting the NULL assignment to "sc_task" and
its notification, with spinlock "sc_state_lock" of the struct
nilfs_sc_info.  Since nilfs_segctor_kill_thread() does a final check to
see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate
the race.

Link: https://lkml.kernel.org/r/20230327175318.8060-1-konishi.ryusuke@gmail.com
Reported-by: syzbot+b08ebcc22f8f3e6be43a@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/00000000000000660d05f7dfa877@google.com
Signed-off-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix kernel-infoleak in nilfs_ioctl_wrap_copy()

2023-03-30T10:51:39+00:00

commit 003587000276f81d0114b5ce773d80c119d8cb30 upstream.

The ioctl helper function nilfs_ioctl_wrap_copy(), which exchanges a
metadata array to/from user space, may copy uninitialized buffer regions
to user space memory for read-only ioctl commands NILFS_IOCTL_GET_SUINFO
and NILFS_IOCTL_GET_CPINFO.

This can occur when the element size of the user space metadata given by
the v_size member of the argument nilfs_argv structure is larger than the
size of the metadata element (nilfs_suinfo structure or nilfs_cpinfo
structure) on the file system side.

KMSAN-enabled kernels detect this issue as follows:

 BUG: KMSAN: kernel-infoleak in instrument_copy_to_user
 include/linux/instrumented.h:121 [inline]
 BUG: KMSAN: kernel-infoleak in _copy_to_user+0xc0/0x100 lib/usercopy.c:33
  instrument_copy_to_user include/linux/instrumented.h:121 [inline]
  _copy_to_user+0xc0/0x100 lib/usercopy.c:33
  copy_to_user include/linux/uaccess.h:169 [inline]
  nilfs_ioctl_wrap_copy+0x6fa/0xc10 fs/nilfs2/ioctl.c:99
  nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
  nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
  nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
  __do_compat_sys_ioctl fs/ioctl.c:968 [inline]
  __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
  __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
  do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
  __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
  do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
  do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
  entry_SYSENTER_compat_after_hwframe+0x70/0x82

 Uninit was created at:
  __alloc_pages+0x9f6/0xe90 mm/page_alloc.c:5572
  alloc_pages+0xab0/0xd80 mm/mempolicy.c:2287
  __get_free_pages+0x34/0xc0 mm/page_alloc.c:5599
  nilfs_ioctl_wrap_copy+0x223/0xc10 fs/nilfs2/ioctl.c:74
  nilfs_ioctl_get_info fs/nilfs2/ioctl.c:1173 [inline]
  nilfs_ioctl+0x2402/0x4450 fs/nilfs2/ioctl.c:1290
  nilfs_compat_ioctl+0x1b8/0x200 fs/nilfs2/ioctl.c:1343
  __do_compat_sys_ioctl fs/ioctl.c:968 [inline]
  __se_compat_sys_ioctl+0x7dd/0x1000 fs/ioctl.c:910
  __ia32_compat_sys_ioctl+0x93/0xd0 fs/ioctl.c:910
  do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
  __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
  do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
  do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
  entry_SYSENTER_compat_after_hwframe+0x70/0x82

 Bytes 16-127 of 3968 are uninitialized
 ...

This eliminates the leak issue by initializing the page allocated as
buffer using get_zeroed_page().

Link: https://lkml.kernel.org/r/20230307085548.6290-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+132fdd2f1e1805fdc591@syzkaller.appspotmail.com
  Link: https://lkml.kernel.org/r/000000000000a5bd2d05f63f04ae@google.com
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

nilfs2: fix underflow in second superblock position calculations

2023-02-17T23:07:05+00:00

Macro NILFS_SB2_OFFSET_BYTES, which computes the position of the second
superblock, underflows when the argument device size is less than 4096
bytes.  Therefore, when using this macro, it is necessary to check in
advance that the device size is not less than a lower limit, or at least
that underflow does not occur.

The current nilfs2 implementation lacks this check, causing out-of-bound
block access when mounting devices smaller than 4096 bytes:

 I/O error, dev loop0, sector 36028797018963960 op 0x0:(READ) flags 0x0
 phys_seg 1 prio class 2
 NILFS (loop0): unable to read secondary superblock (blocksize = 1024)

In addition, when trying to resize the filesystem to a size below 4096
bytes, this underflow occurs in nilfs_resize_fs(), passing a huge number
of segments to nilfs_sufile_resize(), corrupting parameters such as the
number of segments in superblocks.  This causes excessive loop iterations
in nilfs_sufile_resize() during a subsequent resize ioctl, causing
semaphore ns_segctor_sem to block for a long time and hang the writer
thread:

 INFO: task segctord:5067 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc8-syzkaller-00015-gf6feea56f66d #0
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 task:segctord        state:D stack:23456 pid:5067  ppid:2
 flags:0x00004000
 Call Trace:
  
  context_switch kernel/sched/core.c:5293 [inline]
  __schedule+0x1409/0x43f0 kernel/sched/core.c:6606
  schedule+0xc3/0x190 kernel/sched/core.c:6682
  rwsem_down_write_slowpath+0xfcf/0x14a0 kernel/locking/rwsem.c:1190
  nilfs_transaction_lock+0x25c/0x4f0 fs/nilfs2/segment.c:357
  nilfs_segctor_thread_construct fs/nilfs2/segment.c:2486 [inline]
  nilfs_segctor_thread+0x52f/0x1140 fs/nilfs2/segment.c:2570
  kthread+0x270/0x300 kernel/kthread.c:376
  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
  
 ...
 Call Trace:
  
  folio_mark_accessed+0x51c/0xf00 mm/swap.c:515
  __nilfs_get_page_block fs/nilfs2/page.c:42 [inline]
  nilfs_grab_buffer+0x3d3/0x540 fs/nilfs2/page.c:61
  nilfs_mdt_submit_block+0xd7/0x8f0 fs/nilfs2/mdt.c:121
  nilfs_mdt_read_block+0xeb/0x430 fs/nilfs2/mdt.c:176
  nilfs_mdt_get_block+0x12d/0xbb0 fs/nilfs2/mdt.c:251
  nilfs_sufile_get_segment_usage_block fs/nilfs2/sufile.c:92 [inline]
  nilfs_sufile_truncate_range fs/nilfs2/sufile.c:679 [inline]
  nilfs_sufile_resize+0x7a3/0x12b0 fs/nilfs2/sufile.c:777
  nilfs_resize_fs+0x20c/0xed0 fs/nilfs2/super.c:422
  nilfs_ioctl_resize fs/nilfs2/ioctl.c:1033 [inline]
  nilfs_ioctl+0x137c/0x2440 fs/nilfs2/ioctl.c:1301
  ...

This fixes these issues by inserting appropriate minimum device size
checks or anti-underflow checks, depending on where the macro is used.

Link: https://lkml.kernel.org/r/0000000000004e1dfa05f4a48e6b@google.com
Link: https://lkml.kernel.org/r/20230214224043.24141-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: 
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: fix general protection fault in nilfs_btree_insert()

2023-01-12T00:14:21+00:00

If nilfs2 reads a corrupted disk image and tries to reads a b-tree node
block by calling __nilfs_btree_get_block() against an invalid virtual
block address, it returns -ENOENT because conversion of the virtual block
address to a disk block address fails.  However, this return value is the
same as the internal code that b-tree lookup routines return to indicate
that the block being searched does not exist, so functions that operate on
that b-tree may misbehave.

When nilfs_btree_insert() receives this spurious 'not found' code from
nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was
successful and continues the insert operation using incomplete lookup path
data, causing the following crash:

 general protection fault, probably for non-canonical address
 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
 KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
 ...
 RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline]
 RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
 RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238
 Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89
 ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c
 28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02
 ...
 Call Trace:
 
  nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
  nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147
  nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101
  __block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
  __block_write_begin fs/buffer.c:2041 [inline]
  block_write_begin+0x93/0x1e0 fs/buffer.c:2102
  nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261
  generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
  __generic_file_write_iter+0x176/0x400 mm/filemap.c:3900
  generic_file_write_iter+0xab/0x310 mm/filemap.c:3932
  call_write_iter include/linux/fs.h:2186 [inline]
  new_sync_write fs/read_write.c:491 [inline]
  vfs_write+0x7dc/0xc50 fs/read_write.c:584
  ksys_write+0x177/0x2a0 fs/read_write.c:637
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 ...
 

This patch fixes the root cause of this problem by replacing the error
code that __nilfs_btree_get_block() returns on block address conversion
failure from -ENOENT to another internal code -EINVAL which means that the
b-tree metadata is corrupted.

By returning -EINVAL, it propagates without glitches, and for all relevant
b-tree operations, functions in the upper bmap layer output an error
message indicating corrupted b-tree metadata via
nilfs_bmap_convert_error(), and code -EIO will be eventually returned as
it should be.

Link: https://lkml.kernel.org/r/000000000000bd89e205f0e38355@google.com
Link: https://lkml.kernel.org/r/20230105055356.8811-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+ede796cecd5296353515@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

treewide: Convert del_timer() to timer_shutdown()

2022-12-25T21:38:09+00:00

Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&ptr->timer);
    +       timer_shutdown(&ptr->timer);
    |
    -       del_timer_sync(&ptr->timer);
    +       timer_shutdown_sync(&ptr->timer);
    )
      ... when strict
          when != ptr->timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . > /tmp/t.patch
    $ patch -p1 < /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) 
Acked-by: Pavel Machek  [ LED ]
Acked-by: Kalle Valo  [ wireless ]
Acked-by: Paolo Abeni  [ networking ]
Signed-off-by: Linus Torvalds

Merge tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-12-13T01:28:58+00:00

Pull non-MM updates from Andrew Morton:

 - A ptrace API cleanup series from Sergey Shtylyov

 - Fixes and cleanups for kexec from ye xingchen

 - nilfs2 updates from Ryusuke Konishi

 - squashfs feature work from Xiaoming Ni: permit configuration of the
   filesystem's compression concurrency from the mount command line

 - A series from Akinobu Mita which addresses bound checking errors when
   writing to debugfs files

 - A series from Yang Yingliang to address rapidio memory leaks

 - A series from Zheng Yejian to address possible overflow errors in
   encode_comp_t()

 - And a whole shower of singleton patches all over the place

* tag 'mm-nonmm-stable-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (79 commits)
  ipc: fix memory leak in init_mqueue_fs()
  hfsplus: fix bug causing custom uid and gid being unable to be assigned with mount
  rapidio: devices: fix missing put_device in mport_cdev_open
  kcov: fix spelling typos in comments
  hfs: Fix OOB Write in hfs_asc2mac
  hfs: fix OOB Read in __hfs_brec_find
  relay: fix type mismatch when allocating memory in relay_create_buf()
  ocfs2: always read both high and low parts of dinode link count
  io-mapping: move some code within the include guarded section
  kernel: kcsan: kcsan_test: build without structleak plugin
  mailmap: update email for Iskren Chernev
  eventfd: change int to __u64 in eventfd_signal() ifndef CONFIG_EVENTFD
  rapidio: fix possible UAF when kfifo_alloc() fails
  relay: use strscpy() is more robust and safer
  cpumask: limit visibility of FORCE_NR_CPUS
  acct: fix potential integer overflow in encode_comp_t()
  acct: fix accuracy loss for input value of encode_comp_t()
  linux/init.h: include  and 
  rapidio: rio: fix possible name leak in rio_register_mport()
  rapidio: fix possible name leaks when rio_add_device() fails
  ...