linux-stable.git/fs/f2fs, branch v5.4.78

f2fs: handle errors of f2fs_get_meta_page_nofail

2020-11-05T10:43:14+00:00

[ Upstream commit 86f33603f8c51537265ff7ac0320638fd2cbdb1b ]

First problem is we hit BUG_ON() in f2fs_get_sum_page given EIO on
f2fs_get_meta_page_nofail().

Quick fix was not to give any error with infinite loop, but syzbot caught
a case where it goes to that loop from fuzzed image. In turned out we abused
f2fs_get_meta_page_nofail() like in the below call stack.

- f2fs_fill_super
 - f2fs_build_segment_manager
  - build_sit_entries
   - get_current_sit_page

INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
 stack:26960 pid: 6870 ppid:  6869 flags:0x00004006
Call Trace:

Showing all locks held in the system:
1 lock held by khungtaskd/1179:
 #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
 #0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor178/6870:
 #0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229

Actually, we didn't have to use _nofail in this case, since we could return
error to mount(2) already with the error handler.

As a result, this patch tries to 1) remove _nofail callers as much as possible,
2) deal with error case in last remaining caller, f2fs_get_sum_page().

Reported-by: syzbot+ee250ac8137be41d7b13@syzkaller.appspotmail.com
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix to check segment boundary during SIT page readahead

2020-11-05T10:43:13+00:00

[ Upstream commit 6a257471fa42c8c9c04a875cd3a2a22db148e0f0 ]

As syzbot reported:

kernel BUG at fs/f2fs/segment.h:657!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 16220 Comm: syz-executor.0 Not tainted 5.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:f2fs_ra_meta_pages+0xa51/0xdc0 fs/f2fs/segment.h:657
Call Trace:
 build_sit_entries fs/f2fs/segment.c:4195 [inline]
 f2fs_build_segment_manager+0x4b8a/0xa3c0 fs/f2fs/segment.c:4779
 f2fs_fill_super+0x377d/0x6b80 fs/f2fs/super.c:3633
 mount_bdev+0x32e/0x3f0 fs/super.c:1417
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x1387/0x2070 fs/namespace.c:3192
 do_mount fs/namespace.c:3205 [inline]
 __do_sys_mount fs/namespace.c:3413 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

@blkno in f2fs_ra_meta_pages could exceed max segment count, causing panic
in following sanity check in current_sit_addr(), add check condition to
avoid this issue.

Reported-by: syzbot+3698081bcf0bb2d12174@syzkaller.appspotmail.com
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix uninit-value in f2fs_lookup

2020-11-05T10:43:13+00:00

[ Upstream commit 6d7ab88a98c1b7a47c228f8ffb4f44d631eaf284 ]

As syzbot reported:

Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
 f2fs_lookup+0xe05/0x1a80 fs/f2fs/namei.c:503
 lookup_open fs/namei.c:3082 [inline]
 open_last_lookups fs/namei.c:3177 [inline]
 path_openat+0x2729/0x6a90 fs/namei.c:3365
 do_filp_open+0x2b8/0x710 fs/namei.c:3395
 do_sys_openat2+0xa88/0x1140 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_compat_sys_openat fs/open.c:1242 [inline]
 __se_compat_sys_openat+0x2a4/0x310 fs/open.c:1240
 __ia32_compat_sys_openat+0x56/0x70 fs/open.c:1240
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

In f2fs_lookup(), @res_page could be used before being initialized,
because in __f2fs_find_entry(), once F2FS_I(dir)->i_current_depth was
been fuzzed to zero, then @res_page will never be initialized, causing
this kmsan warning, relocating @res_page initialization place to fix
this bug.

Reported-by: syzbot+0eac6f0bbd558fd866d7@syzkaller.appspotmail.com
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: add trace exit in exception path

2020-11-05T10:43:13+00:00

[ Upstream commit 9b66482282888d02832b7d90239e1cdb18e4b431 ]

Missing the trace exit in f2fs_sync_dirty_inodes

Signed-off-by: Zhang Qilong 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info

2020-10-29T08:57:52+00:00

[ Upstream commit ae284d87abade58c8db7760c808f311ef1ce693c ]

syzkaller found that with CONFIG_DEBUG_KOBJECT_RELEASE=y, unmounting an
f2fs filesystem could result in the following splat:

  kobject: 'loop5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 250)
  kobject: 'f2fs_xattr_entry-7:5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 750)
  ------------[ cut here ]------------
  ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x98
  WARNING: CPU: 0 PID: 699 at lib/debugobjects.c:485 debug_print_object+0x180/0x240
  Kernel panic - not syncing: panic_on_warn set ...
  CPU: 0 PID: 699 Comm: syz-executor.5 Tainted: G S                5.9.0-rc8+ #101
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x0/0x4d8
   show_stack+0x34/0x48
   dump_stack+0x174/0x1f8
   panic+0x360/0x7a0
   __warn+0x244/0x2ec
   report_bug+0x240/0x398
   bug_handler+0x50/0xc0
   call_break_hook+0x160/0x1d8
   brk_handler+0x30/0xc0
   do_debug_exception+0x184/0x340
   el1_dbg+0x48/0xb0
   el1_sync_handler+0x170/0x1c8
   el1_sync+0x80/0x100
   debug_print_object+0x180/0x240
   debug_check_no_obj_freed+0x200/0x430
   slab_free_freelist_hook+0x190/0x210
   kfree+0x13c/0x460
   f2fs_put_super+0x624/0xa58
   generic_shutdown_super+0x120/0x300
   kill_block_super+0x94/0xf8
   kill_f2fs_super+0x244/0x308
   deactivate_locked_super+0x104/0x150
   deactivate_super+0x118/0x148
   cleanup_mnt+0x27c/0x3c0
   __cleanup_mnt+0x28/0x38
   task_work_run+0x10c/0x248
   do_notify_resume+0x9d4/0x1188
   work_pending+0x8/0x34c

Like the error handling for f2fs_register_sysfs(), we need to wait for
the kobject to be destroyed before returning to prevent a potential
use-after-free.

Fixes: bf9e697ecd42 ("f2fs: expose features to sysfs entry")
Cc: Jaegeuk Kim 
Cc: Chao Yu 
Signed-off-by: Jamie Iles 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: stop GC when the victim becomes fully valid

2020-10-01T11:17:21+00:00

[ Upstream commit 803e74be04b32f7785742dcabfc62116718fbb06 ]

We must stop GC, once the segment becomes fully valid. Otherwise, it can
produce another dirty segments by moving valid blocks in the segment partially.

Ramon hit no free segment panic sometimes and saw this case happens when
validating reliable file pinning feature.

Signed-off-by: Ramon Pantin 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: avoid kernel panic on corruption test

2020-10-01T11:17:16+00:00

[ Upstream commit bc005a4d5347da68e690f78d365d8927c87dc85a ]

xfstests/generic/475 complains kernel warn/panic while testing corrupted disk.

Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: Return EOF on unaligned end of file DIO read

2020-09-23T10:40:38+00:00

[ Upstream commit 20d0a107fb35f37578b919f62bd474d6d358d579 ]

Reading past end of file returns EOF for aligned reads but -EINVAL for
unaligned reads on f2fs.  While documentation is not strict about this
corner case, most filesystem returns EOF on this case, like iomap
filesystems.  This patch consolidates the behavior for f2fs, by making
it return EOF(0).

it can be verified by a read loop on a file that does a partial read
before EOF (A file that doesn't end at an aligned address).  The
following code fails on an unaligned file on f2fs, but not on
btrfs, ext4, and xfs.

  while (done < total) {
    ssize_t delta = pread(fd, buf + done, total - done, off + done);
    if (!delta)
      break;
    ...
  }

It is arguable whether filesystems should actually return EOF or
-EINVAL, but since iomap filesystems support it, and so does the
original DIO code, it seems reasonable to consolidate on that.

Signed-off-by: Gabriel Krisman Bertazi 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix indefinite loop scanning for free nid

2020-09-23T10:40:37+00:00

[ Upstream commit e2cab031ba7b5003cd12185b3ef38f1a75e3dae8 ]

If the sbi->ckpt->next_free_nid is not NAT block aligned and if there
are free nids in that NAT block between the start of the block and
next_free_nid, then those free nids will not be scanned in scan_nat_page().
This results into mismatch between nm_i->available_nids and the sum of
nm_i->free_nid_count of all NAT blocks scanned. And nm_i->available_nids
will always be greater than the sum of free nids in all the blocks.
Under this condition, if we use all the currently scanned free nids,
then it will loop forever in f2fs_alloc_nid() as nm_i->available_nids
is still not zero but nm_i->free_nid_count of that partially scanned
NAT block is zero.

Fix this to align the nm_i->next_scan_nid to the first nid of the
corresponding NAT block.

Signed-off-by: Sahitya Tummala 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin

f2fs: fix use-after-free issue

2020-09-03T09:26:46+00:00

[ Upstream commit 99c787cfd2bd04926f1f553b30bd7dcea2caaba1 ]

During umount, f2fs_put_super() unregisters procfs entries after
f2fs_destroy_segment_manager(), it may cause use-after-free
issue when umount races with procfs accessing, fix it by relocating
f2fs_unregister_sysfs().

[Chao Yu: change commit title/message a bit]

Signed-off-by: Li Guifu 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Sasha Levin