linux-stable.git/fs/jffs2, branch linux-5.17.y

jffs2: fix memory leak in jffs2_do_fill_super

2022-06-14T16:41:21+00:00

[ Upstream commit c14adb1cf70a984ed081c67e9d27bc3caad9537c ]

If jffs2_iget() or d_make_root() in jffs2_do_fill_super() returns
an error, we can observe the following kmemleak report:

--------------------------------------------
unreferenced object 0xffff888105a65340 (size 64):
  comm "mount", pid 710, jiffies 4302851558 (age 58.239s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [] kmem_cache_alloc_trace+0x475/0x8a0
    [] jffs2_sum_init+0x96/0x1a0
    [] jffs2_do_mount_fs+0x745/0x2120
    [] jffs2_do_fill_super+0x35c/0x810
    [] jffs2_fill_super+0x2b9/0x3b0
    [...]
unreferenced object 0xffff8881bd7f0000 (size 65536):
  comm "mount", pid 710, jiffies 4302851558 (age 58.239s)
  hex dump (first 32 bytes):
    bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
    bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  backtrace:
    [] kmalloc_order+0xda/0x110
    [] kmalloc_order_trace+0x21/0x130
    [] __kmalloc+0x711/0x8a0
    [] jffs2_sum_init+0xd9/0x1a0
    [] jffs2_do_mount_fs+0x745/0x2120
    [] jffs2_do_fill_super+0x35c/0x810
    [] jffs2_fill_super+0x2b9/0x3b0
    [...]
--------------------------------------------

This is because the resources allocated in jffs2_sum_init() are not
released. Call jffs2_sum_exit() to release these resources to solve
the problem.

Fixes: e631ddba5887 ("[JFFS2] Add erase block summary support (mount time improvement)")
Signed-off-by: Baokun Li 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

jffs2: fix memory leak in jffs2_scan_medium

2022-04-08T11:57:19+00:00

commit 9cdd3128874f5fe759e2c4e1360ab7fb96a8d1df upstream.

If an error is returned in jffs2_scan_eraseblock() and some memory
has been added to the jffs2_summary *s, we can observe the following
kmemleak report:

--------------------------------------------
unreferenced object 0xffff88812b889c40 (size 64):
  comm "mount", pid 692, jiffies 4294838325 (age 34.288s)
  hex dump (first 32 bytes):
    40 48 b5 14 81 88 ff ff 01 e0 31 00 00 00 50 00  @H........1...P.
    00 00 01 00 00 00 01 00 00 00 02 00 00 00 09 08  ................
  backtrace:
    [] __kmalloc+0x613/0x910
    [] jffs2_sum_add_dirent_mem+0x5c/0xa0
    [] jffs2_scan_medium.cold+0x36e5/0x4794
    [] jffs2_do_mount_fs.cold+0xa7/0x2267
    [] jffs2_do_fill_super+0x383/0xc30
    [] jffs2_fill_super+0x2ea/0x4c0
    [] mtd_get_sb+0x254/0x400
    [] mtd_get_sb_by_nr+0x4f/0xd0
    [] get_tree_mtd+0x498/0x840
    [] jffs2_get_tree+0x25/0x30
    [] vfs_get_tree+0x8d/0x2e0
    [] path_mount+0x50f/0x1e50
    [] do_mount+0x107/0x130
    [] __se_sys_mount+0x1c5/0x2f0
    [] __x64_sys_mount+0xc7/0x160
    [] do_syscall_64+0x45/0x70
unreferenced object 0xffff888114b54840 (size 32):
  comm "mount", pid 692, jiffies 4294838325 (age 34.288s)
  hex dump (first 32 bytes):
    c0 75 b5 14 81 88 ff ff 02 e0 02 00 00 00 02 00  .u..............
    00 00 84 00 00 00 44 00 00 00 6b 6b 6b 6b 6b a5  ......D...kkkkk.
  backtrace:
    [] kmem_cache_alloc_trace+0x584/0x880
    [] jffs2_sum_add_inode_mem+0x54/0x90
    [] jffs2_scan_medium.cold+0x4481/0x4794
    [...]
unreferenced object 0xffff888114b57280 (size 32):
  comm "mount", pid 692, jiffies 4294838393 (age 34.357s)
  hex dump (first 32 bytes):
    10 d5 6c 11 81 88 ff ff 08 e0 05 00 00 00 01 00  ..l.............
    00 00 38 02 00 00 28 00 00 00 6b 6b 6b 6b 6b a5  ..8...(...kkkkk.
  backtrace:
    [] kmem_cache_alloc_trace+0x584/0x880
    [] jffs2_sum_add_xattr_mem+0x54/0x90
    [] jffs2_scan_medium.cold+0x298c/0x4794
    [...]
unreferenced object 0xffff8881116cd510 (size 16):
  comm "mount", pid 692, jiffies 4294838395 (age 34.355s)
  hex dump (first 16 bytes):
    00 00 00 00 00 00 00 00 09 e0 60 02 00 00 6b a5  ..........`...k.
  backtrace:
    [] kmem_cache_alloc_trace+0x584/0x880
    [] jffs2_sum_add_xref_mem+0x54/0x90
    [] jffs2_scan_medium.cold+0x3a20/0x4794
    [...]
--------------------------------------------

Therefore, we should call jffs2_sum_reset_collected(s) on exit to
release the memory added in s. In addition, a new tag "out_buf" is
added to prevent the NULL pointer reference caused by s being NULL.
(thanks to Zhang Yi for this analysis)

Fixes: e631ddba5887 ("[JFFS2] Add erase block summary support (mount time improvement)")
Cc: stable@vger.kernel.org
Co-developed-with: Zhihao Cheng 
Signed-off-by: Baokun Li 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

jffs2: fix memory leak in jffs2_do_mount_fs

2022-04-08T11:57:19+00:00

commit d051cef784de4d54835f6b6836d98a8f6935772c upstream.

If jffs2_build_filesystem() in jffs2_do_mount_fs() returns an error,
we can observe the following kmemleak report:

--------------------------------------------
unreferenced object 0xffff88811b25a640 (size 64):
  comm "mount", pid 691, jiffies 4294957728 (age 71.952s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [] kmem_cache_alloc_trace+0x584/0x880
    [] jffs2_sum_init+0x86/0x130
    [] jffs2_do_mount_fs+0x798/0xac0
    [] jffs2_do_fill_super+0x383/0xc30
    [] jffs2_fill_super+0x2ea/0x4c0
    [...]
unreferenced object 0xffff88812c760000 (size 65536):
  comm "mount", pid 691, jiffies 4294957728 (age 71.952s)
  hex dump (first 32 bytes):
    bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
    bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
  backtrace:
    [] __kmalloc+0x6b9/0x910
    [] jffs2_sum_init+0xd7/0x130
    [] jffs2_do_mount_fs+0x798/0xac0
    [] jffs2_do_fill_super+0x383/0xc30
    [] jffs2_fill_super+0x2ea/0x4c0
    [...]
--------------------------------------------

This is because the resources allocated in jffs2_sum_init() are not
released. Call jffs2_sum_exit() to release these resources to solve
the problem.

Fixes: e631ddba5887 ("[JFFS2] Add erase block summary support (mount time improvement)")
Cc: stable@vger.kernel.org
Signed-off-by: Baokun Li 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

jffs2: fix use-after-free in jffs2_clear_xattr_subsystem

2022-04-08T11:57:19+00:00

commit 4c7c44ee1650677fbe89d86edbad9497b7679b5c upstream.

When we mount a jffs2 image, assume that the first few blocks of
the image are normal and contain at least one xattr-related inode,
but the next block is abnormal. As a result, an error is returned
in jffs2_scan_eraseblock(). jffs2_clear_xattr_subsystem() is then
called in jffs2_build_filesystem() and then again in
jffs2_do_fill_super().

Finally we can observe the following report:
 ==================================================================
 BUG: KASAN: use-after-free in jffs2_clear_xattr_subsystem+0x95/0x6ac
 Read of size 8 at addr ffff8881243384e0 by task mount/719

 Call Trace:
  dump_stack+0x115/0x16b
  jffs2_clear_xattr_subsystem+0x95/0x6ac
  jffs2_do_fill_super+0x84f/0xc30
  jffs2_fill_super+0x2ea/0x4c0
  mtd_get_sb+0x254/0x400
  mtd_get_sb_by_nr+0x4f/0xd0
  get_tree_mtd+0x498/0x840
  jffs2_get_tree+0x25/0x30
  vfs_get_tree+0x8d/0x2e0
  path_mount+0x50f/0x1e50
  do_mount+0x107/0x130
  __se_sys_mount+0x1c5/0x2f0
  __x64_sys_mount+0xc7/0x160
  do_syscall_64+0x45/0x70
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

 Allocated by task 719:
  kasan_save_stack+0x23/0x60
  __kasan_kmalloc.constprop.0+0x10b/0x120
  kasan_slab_alloc+0x12/0x20
  kmem_cache_alloc+0x1c0/0x870
  jffs2_alloc_xattr_ref+0x2f/0xa0
  jffs2_scan_medium.cold+0x3713/0x4794
  jffs2_do_mount_fs.cold+0xa7/0x2253
  jffs2_do_fill_super+0x383/0xc30
  jffs2_fill_super+0x2ea/0x4c0
 [...]

 Freed by task 719:
  kmem_cache_free+0xcc/0x7b0
  jffs2_free_xattr_ref+0x78/0x98
  jffs2_clear_xattr_subsystem+0xa1/0x6ac
  jffs2_do_mount_fs.cold+0x5e6/0x2253
  jffs2_do_fill_super+0x383/0xc30
  jffs2_fill_super+0x2ea/0x4c0
 [...]

 The buggy address belongs to the object at ffff8881243384b8
  which belongs to the cache jffs2_xattr_ref of size 48
 The buggy address is located 40 bytes inside of
  48-byte region [ffff8881243384b8, ffff8881243384e8)
 [...]
 ==================================================================

The triggering of the BUG is shown in the following stack:
-----------------------------------------------------------
jffs2_fill_super
  jffs2_do_fill_super
    jffs2_do_mount_fs
      jffs2_build_filesystem
        jffs2_scan_medium
          jffs2_scan_eraseblock        <--- ERROR
        jffs2_clear_xattr_subsystem    <--- free
    jffs2_clear_xattr_subsystem        <--- free again
-----------------------------------------------------------

An error is returned in jffs2_do_mount_fs(). If the error is returned
by jffs2_sum_init(), the jffs2_clear_xattr_subsystem() does not need to
be executed. If the error is returned by jffs2_build_filesystem(), the
jffs2_clear_xattr_subsystem() also does not need to be executed again.
So move jffs2_clear_xattr_subsystem() from 'out_inohash' to 'out_root'
to fix this UAF problem.

Fixes: aa98d7cf59b5 ("[JFFS2][XATTR] XATTR support on JFFS2 (version. 5)")
Cc: stable@vger.kernel.org
Reported-by: Hulk Robot 
Signed-off-by: Baokun Li 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2022-01-17T03:49:30+00:00

Pull signal/exit/ptrace updates from Eric Biederman:
 "This set of changes deletes some dead code, makes a lot of cleanups
  which hopefully make the code easier to follow, and fixes bugs found
  along the way.

  The end-game which I have not yet reached yet is for fatal signals
  that generate coredumps to be short-circuit deliverable from
  complete_signal, for force_siginfo_to_task not to require changing
  userspace configured signal delivery state, and for the ptrace stops
  to always happen in locations where we can guarantee on all
  architectures that the all of the registers are saved and available on
  the stack.

  Removal of profile_task_ext, profile_munmap, and profile_handoff_task
  are the big successes for dead code removal this round.

  A bunch of small bug fixes are included, as most of the issues
  reported were small enough that they would not affect bisection so I
  simply added the fixes and did not fold the fixes into the changes
  they were fixing.

  There was a bug that broke coredumps piped to systemd-coredump. I
  dropped the change that caused that bug and replaced it entirely with
  something much more restrained. Unfortunately that required some
  rebasing.

  Some successes after this set of changes: There are few enough calls
  to do_exit to audit in a reasonable amount of time. The lifetime of
  struct kthread now matches the lifetime of struct task, and the
  pointer to struct kthread is no longer stored in set_child_tid. The
  flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
  removed. Issues where task->exit_code was examined with
  signal->group_exit_code should been examined were fixed.

  There are several loosely related changes included because I am
  cleaning up and if I don't include them they will probably get lost.

  The original postings of these changes can be found at:
     https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org

  I trimmed back the last set of changes to only the obviously correct
  once. Simply because there was less time for review than I had hoped"

* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
  ptrace/m68k: Stop open coding ptrace_report_syscall
  ptrace: Remove unused regs argument from ptrace_report_syscall
  ptrace: Remove second setting of PT_SEIZED in ptrace_attach
  taskstats: Cleanup the use of task->exit_code
  exit: Use the correct exit_code in /proc//stat
  exit: Fix the exit_code for wait_task_zombie
  exit: Coredumps reach do_group_exit
  exit: Remove profile_handoff_task
  exit: Remove profile_task_exit & profile_munmap
  signal: clean up kernel-doc comments
  signal: Remove the helper signal_group_exit
  signal: Rename group_exit_task group_exec_task
  coredump: Stop setting signal->group_exit_task
  signal: Remove SIGNAL_GROUP_COREDUMP
  signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
  signal: Make coredump handling explicit in complete_signal
  signal: Have prepare_signal detect coredumps using signal->core_state
  signal: Have the oom killer detect coredumps using signal->core_state
  exit: Move force_uaccess back into do_exit
  exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
  ...

jffs2: GC deadlock reading a page that is used in jffs2_write_begin()

2021-12-23T21:33:41+00:00

GC task can deadlock in read_cache_page() because it may attempt
to release a page that is actually allocated by another task in
jffs2_write_begin().
The reason is that in jffs2_write_begin() there is a small window
a cache page is allocated for use but not set Uptodate yet.

This ends up with a deadlock between two tasks:
1) A task (e.g. file copy)
   - jffs2_write_begin() locks a cache page
   - jffs2_write_end() tries to lock "alloc_sem" from
	 jffs2_reserve_space() <-- STUCK
2) GC task (jffs2_gcd_mtd3)
   - jffs2_garbage_collect_pass() locks "alloc_sem"
   - try to lock the same cache page in read_cache_page() <-- STUCK

So to avoid this deadlock, hold "alloc_sem" in jffs2_write_begin()
while reading data in a cache page.

Signed-off-by: Kyeong Yoo 
Signed-off-by: Richard Weinberger

exit: Rename complete_and_exit to kthread_complete_and_exit

2021-12-13T18:04:45+00:00

Update complete_and_exit to call kthread_exit instead of do_exit.

Change the name to reflect this change in functionality.  All of the
users of complete_and_exit are causing the current kthread to exit so
this change makes it clear what is happening.

Move the implementation of kthread_complete_and_exit from
kernel/exit.c to to kernel/kthread.c.  As this function is kthread
specific it makes most sense to live with the kthread functions.

There are no functional change.

Signed-off-by: "Eric W. Biederman"

vfs: add rcu argument to ->get_acl() callback

2021-08-18T20:08:24+00:00

Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.

Signed-off-by: Miklos Szeredi

Merge tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs

2021-05-05T01:08:40+00:00

Pull JFFS2, UBI and UBIFS updates from Richard Weinberger:
 "JFFS2:
   - Use splice_write()
   - Fix for a slab-out-of-bounds bug

  UBI:
   - Fix for clang related warnings
   - Code cleanup

  UBIFS:
   - Fix for inode rebirth at replay
   - Set s_uuid
   - Use zstd for default filesystem"

* tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubi: Remove unnecessary struct declaration
  jffs2: Hook up splice_write callback
  jffs2: avoid Wempty-body warnings
  jffs2: Fix kasan slab-out-of-bounds problem
  ubi: Fix fall-through warnings for Clang
  ubifs: Report max LEB count at mount time
  ubifs: Set s_uuid in super block to support ima/evm uuid options
  ubifs: Default to zstd compression
  ubifs: Only check replay with inode type to judge if inode linked

jffs2: Hook up splice_write callback

2021-04-15T20:01:14+00:00

overlayfs using jffs2 as the upper filesystem would fail in some cases
since moving to v5.10. The test case used was to run 'touch' on a file
that exists in the lower fs, causing the modification time to be
updated. It returns EINVAL when the bug is triggered.

A bisection showed this was introduced in v5.9-rc1, with commit
36e2c7421f02 ("fs: don't allow splice read/write without explicit ops").
Reverting that commit restores the expected behaviour.

Some digging showed that this was due to jffs2 lacking an implementation
of splice_write. (For unknown reasons the warn_unsupported that should
trigger was not displaying any output).

Adding this patch resolved the issue and the test now passes.

Cc: stable@vger.kernel.org
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Joel Stanley 
Reviewed-by: Christoph Hellwig 
Tested-by: Lei YU 
Signed-off-by: Richard Weinberger