linux.git/fs/nilfs2, branch v6.11

nilfs2: fix state management in error path of log writing function

2024-09-02T00:59:00+00:00

After commit a694291a6211 ("nilfs2: separate wait function from
nilfs_segctor_write") was applied, the log writing function
nilfs_segctor_do_construct() was able to issue I/O requests continuously
even if user data blocks were split into multiple logs across segments,
but two potential flaws were introduced in its error handling.

First, if nilfs_segctor_begin_construction() fails while creating the
second or subsequent logs, the log writing function returns without
calling nilfs_segctor_abort_construction(), so the writeback flag set on
pages/folios will remain uncleared.  This causes page cache operations to
hang waiting for the writeback flag.  For example,
truncate_inode_pages_final(), which is called via nilfs_evict_inode() when
an inode is evicted from memory, will hang.

Second, the NILFS_I_COLLECTED flag set on normal inodes remain uncleared. 
As a result, if the next log write involves checkpoint creation, that's
fine, but if a partial log write is performed that does not, inodes with
NILFS_I_COLLECTED set are erroneously removed from the "sc_dirty_files"
list, and their data and b-tree blocks may not be written to the device,
corrupting the block mapping.

Fix these issues by uniformly calling nilfs_segctor_abort_construction()
on failure of each step in the loop in nilfs_segctor_do_construct(),
having it clean up logs and segment usages according to progress, and
correcting the conditions for calling nilfs_redirty_inodes() to ensure
that the NILFS_I_COLLECTED flag is cleared.

Link: https://lkml.kernel.org/r/20240814101119.4070-1-konishi.ryusuke@gmail.com
Fixes: a694291a6211 ("nilfs2: separate wait function from nilfs_segctor_write")
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: fix missing cleanup on rollforward recovery error

2024-09-02T00:59:00+00:00

In an error injection test of a routine for mount-time recovery, KASAN
found a use-after-free bug.

It turned out that if data recovery was performed using partial logs
created by dsync writes, but an error occurred before starting the log
writer to create a recovered checkpoint, the inodes whose data had been
recovered were left in the ns_dirty_files list of the nilfs object and
were not freed.

Fix this issue by cleaning up inodes that have read the recovery data if
the recovery routine fails midway before the log writer starts.

Link: https://lkml.kernel.org/r/20240810065242.3701-1-konishi.ryusuke@gmail.com
Fixes: 0f3e1c7f23f8 ("nilfs2: recovery functions")
Signed-off-by: Ryusuke Konishi 
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: protect references to superblock parameters exposed in sysfs

2024-09-02T00:59:00+00:00

The superblock buffers of nilfs2 can not only be overwritten at runtime
for modifications/repairs, but they are also regularly swapped, replaced
during resizing, and even abandoned when degrading to one side due to
backing device issues.  So, accessing them requires mutual exclusion using
the reader/writer semaphore "nilfs->ns_sem".

Some sysfs attribute show methods read this superblock buffer without the
necessary mutual exclusion, which can cause problems with pointer
dereferencing and memory access, so fix it.

Link: https://lkml.kernel.org/r/20240811100320.9913-1-konishi.ryusuke@gmail.com
Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/ group")
Signed-off-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: handle inconsistent state in nilfs_btnode_create_block()

2024-07-26T21:33:10+00:00

Syzbot reported that a buffer state inconsistency was detected in
nilfs_btnode_create_block(), triggering a kernel bug.

It is not appropriate to treat this inconsistency as a bug; it can occur
if the argument block address (the buffer index of the newly created
block) is a virtual block number and has been reallocated due to
corruption of the bitmap used to manage its allocation state.

So, modify nilfs_btnode_create_block() and its callers to treat it as a
possible filesystem error, rather than triggering a kernel bug.

Link: https://lkml.kernel.org/r/20240725052007.4562-1-konishi.ryusuke@gmail.com
Fixes: a60be987d45d ("nilfs2: B-tree node cache")
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+89cc4f2324ed37988b60@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=89cc4f2324ed37988b60
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-07-22T00:56:22+00:00

Pull non-MM updates from Andrew Morton:

 - In the series "treewide: Refactor heap related implementation",
   Kuan-Wei Chiu has significantly reworked the min_heap library code
   and has taught bcachefs to use the new more generic implementation.

 - Yury Norov's series "Cleanup cpumask.h inclusion in core headers"
   reworks the cpumask and nodemask headers to make things generally
   more rational.

 - Kuan-Wei Chiu has sent along some maintenance work against our
   sorting library code in the series "lib/sort: Optimizations and
   cleanups".

 - More library maintainance work from Christophe Jaillet in the series
   "Remove usage of the deprecated ida_simple_xx() API".

 - Ryusuke Konishi continues with the nilfs2 fixes and clanups in the
   series "nilfs2: eliminate the call to inode_attach_wb()".

 - Kuan-Ying Lee has some fixes to the gdb scripts in the series "Fix
   GDB command error".

 - Plus the usual shower of singleton patches all over the place. Please
   see the relevant changelogs for details.

* tag 'mm-nonmm-stable-2024-07-21-15-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (98 commits)
  ia64: scrub ia64 from poison.h
  watchdog/perf: properly initialize the turbo mode timestamp and rearm counter
  tsacct: replace strncpy() with strscpy()
  lib/bch.c: use swap() to improve code
  test_bpf: convert comma to semicolon
  init/modpost: conditionally check section mismatch to __meminit*
  init: remove unused __MEMINIT* macros
  nilfs2: Constify struct kobj_type
  nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro
  math: rational: add missing MODULE_DESCRIPTION() macro
  lib/zlib: add missing MODULE_DESCRIPTION() macro
  fs: ufs: add MODULE_DESCRIPTION()
  lib/rbtree.c: fix the example typo
  ocfs2: add bounds checking to ocfs2_check_dir_entry()
  fs: add kernel-doc comments to ocfs2_prepare_orphan_dir()
  coredump: simplify zap_process()
  selftests/fpu: add missing MODULE_DESCRIPTION() macro
  compiler.h: simplify data_race() macro
  build-id: require program headers to be right after ELF header
  resource: add missing MODULE_DESCRIPTION()
  ...

nilfs2: Constify struct kobj_type

2024-07-12T23:39:52+00:00

'struct kobj_type' is not modified in this driver. It is only used with
kobject_init_and_add() which takes a "const struct kobj_type *" parameter.

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  22403	   4184	     24	  26611	   67f3	fs/nilfs2/sysfs.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  22723	   3928	     24	  26675	   6833	fs/nilfs2/sysfs.o

Link: https://lkml.kernel.org/r/20240708143242.3296-1-konishi.ryusuke@gmail.com
Signed-off-by: Christophe JAILLET 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton

Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix

2024-07-06T18:44:41+00:00

crashes from deferred split racing folio migration", needed by "mm:
migrate: split folio_migrate_mapping()".

nilfs2: avoid undefined behavior in nilfs_cnt32_ge macro

2024-07-05T06:43:11+00:00

According to the C standard 3.4.3p3, the result of signed integer overflow
is undefined.  The macro nilfs_cnt32_ge(), which compares two sequence
numbers, uses signed integer subtraction that can overflow, and therefore
the result of the calculation may differ from what is expected due to
undefined behavior in different environments.

Similar to an earlier change to the jiffies-related comparison macros in
commit 5a581b367b5d ("jiffies: Avoid undefined behavior from signed
overflow"), avoid this potential issue by changing the definition of the
macro to perform the subtraction as unsigned integers, then cast the
result to a signed integer for comparison.

Link: https://lkml.kernel.org/r/20130727225828.GA11864@linux.vnet.ibm.com
Link: https://lkml.kernel.org/r/20240702183512.6390-1-konishi.ryusuke@gmail.com
Fixes: 9ff05123e3bf ("nilfs2: segment constructor")
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton

nilfs2: fix kernel bug on rename operation of broken directory

2024-07-04T05:40:38+00:00

Syzbot reported that in rename directory operation on broken directory on
nilfs2, __block_write_begin_int() called to prepare block write may fail
BUG_ON check for access exceeding the folio/page size.

This is because nilfs_dotdot(), which gets parent directory reference
entry ("..") of the directory to be moved or renamed, does not check
consistency enough, and may return location exceeding folio/page size for
broken directories.

Fix this issue by checking required directory entries ("." and "..") in
the first chunk of the directory in nilfs_dotdot().

Link: https://lkml.kernel.org/r/20240628165107.9006-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Reported-by: syzbot+d3abed1ad3d367fa2627@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d3abed1ad3d367fa2627
Fixes: 2ba466d74ed7 ("nilfs2: directory entry operations")
Tested-by: Ryusuke Konishi 
Cc: 
Signed-off-by: Andrew Morton

nilfs2: fix incorrect inode allocation from reserved inodes

2024-07-04T02:30:16+00:00

If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.

Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.

If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.

Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.

Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi 
Cc: Hillf Danton 
Cc: Jan Kara 
Cc: Matthew Wilcox (Oracle) 
Cc: 
Signed-off-by: Andrew Morton