linux.git/fs/f2fs/node.c, branch v5.12.5

f2fs: fix to avoid out-of-bounds memory access

2021-05-12T06:39:55+00:00

commit b862676e371715456c9dade7990c8004996d0d9e upstream.

butt3rflyh4ck  reported a bug found by
syzkaller fuzzer with custom modifications in 5.12.0-rc3+ [1]:

 dump_stack+0xfa/0x151 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x82/0x32c mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
 f2fs_test_bit fs/f2fs/f2fs.h:2572 [inline]
 current_nat_addr fs/f2fs/node.h:213 [inline]
 get_next_nat_page fs/f2fs/node.c:123 [inline]
 __flush_nat_entry_set fs/f2fs/node.c:2888 [inline]
 f2fs_flush_nat_entries+0x258e/0x2960 fs/f2fs/node.c:2991
 f2fs_write_checkpoint+0x1372/0x6a70 fs/f2fs/checkpoint.c:1640
 f2fs_issue_checkpoint+0x149/0x410 fs/f2fs/checkpoint.c:1807
 f2fs_sync_fs+0x20f/0x420 fs/f2fs/super.c:1454
 __sync_filesystem fs/sync.c:39 [inline]
 sync_filesystem fs/sync.c:67 [inline]
 sync_filesystem+0x1b5/0x260 fs/sync.c:48
 generic_shutdown_super+0x70/0x370 fs/super.c:448
 kill_block_super+0x97/0xf0 fs/super.c:1394

The root cause is, if nat entry in checkpoint journal area is corrupted,
e.g. nid of journalled nat entry exceeds max nid value, during checkpoint,
once it tries to flush nat journal to NAT area, get_next_nat_page() may
access out-of-bounds memory on nat_bitmap due to it uses wrong nid value
as bitmap offset.

[1] https://lore.kernel.org/lkml/CAFcO6XOMWdr8pObek6eN6-fs58KG9doRFadgJj-FnF-1x43s2g@mail.gmail.com/T/#u

Reported-and-tested-by: butt3rflyh4ck 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Greg Kroah-Hartman

block: Add bio_max_segs

2021-02-26T22:49:51+00:00

It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the
sign to be the same.  Introduce bio_max_segs() and change BIO_MAX_PAGES to
be unsigned to make it easier for the users.

Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Matthew Wilcox (Oracle) 
Signed-off-by: Jens Axboe

f2fs: deprecate f2fs_trace_io

2021-01-27T23:20:07+00:00

This patch deprecates f2fs_trace_io, since f2fs uses page->private more broadly,
resulting in more buggy cases.

Acked-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Replace expression with offsetof()

2021-01-27T23:20:00+00:00

Use the existing offsetof() macro instead of duplicating code.

Signed-off-by: Zheng Yongjun 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to account inline xattr correctly during recovery

2020-12-08T22:25:41+00:00

During recovery, we may missed to update inline xattr count correctly,
fix it.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: avoid race condition for shrinker count

2020-12-03T08:59:26+00:00

Light reported sometimes shinker gets nat_cnt < dirty_nat_cnt resulting in
wrong do_shinker work. Let's avoid to return insane overflowed value by adding
single tracking value.

Reported-by: Light Hsieh 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: call f2fs_get_meta_page_retry for nat page

2020-11-02T16:33:01+00:00

When running fault injection test, if we don't stop checkpoint, some stale
NAT entries were flushed which breaks consistency.

Fixes: 86f33603f8c5 ("f2fs: handle errors of f2fs_get_meta_page_nofail")
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: handle errors of f2fs_get_meta_page_nofail

2020-10-14T06:23:29+00:00

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

f2fs: remove unused check on version_bitmap

2020-09-29T08:48:33+00:00

A NULL will not be return by __bitmap_ptr here.
Remove the unused check.

Signed-off-by: Wang Xiaojun 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: clean up kvfree

2020-09-14T18:15:37+00:00

After commit 0b6d4ca04a86 ("f2fs: don't return vmalloc() memory from
f2fs_kmalloc()"), f2fs_k{m,z}alloc() will not return vmalloc()'ed
memory, so clean up to use kfree() instead of kvfree() to free
vmalloc()'ed memory.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim