releases/4.19.51/f2fs-fix-to-avoid-panic-in-dec_valid_block_count.patch

   1 From 4cd3dcac8a5ed0de17b003d84a0d8d73adfc2f87 Mon Sep 17 00:00:00 2001
   2 From: Chao Yu <yuchao0@huawei.com>
   3 Date: Mon, 15 Apr 2019 15:28:30 +0800
   4 Subject: f2fs: fix to avoid panic in dec_valid_block_count()
   5
   6 [ Upstream commit 5e159cd349bf3a31fb7e35c23a93308eb30f4f71 ]
   7
   8 As Jungyeon reported in bugzilla:
   9
  10 https://bugzilla.kernel.org/show_bug.cgi?id=203209
  11
  12 - Overview
  13 When mounting the attached crafted image and running program, I got this error.
  14 Additionally, it hangs on sync after the this script.
  15
  16 The image is intentionally fuzzed from a normal f2fs image for testing and I enabled option CONFIG_F2FS_CHECK_FS on.
  17
  18 - Reproduces
  19 cc poc_01.c
  20 ./run.sh f2fs
  21 sync
  22
  23  kernel BUG at fs/f2fs/f2fs.h:1788!
  24  RIP: 0010:f2fs_truncate_data_blocks_range+0x342/0x350
  25  Call Trace:
  26   f2fs_truncate_blocks+0x36d/0x3c0
  27   f2fs_truncate+0x88/0x110
  28   f2fs_setattr+0x3e1/0x460
  29   notify_change+0x2da/0x400
  30   do_truncate+0x6d/0xb0
  31   do_sys_ftruncate+0xf1/0x160
  32   do_syscall_64+0x43/0xf0
  33   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  34
  35 The reason is dec_valid_block_count() will trigger kernel panic due to
  36 inconsistent count in between inode.i_blocks and actual block.
  37
  38 To avoid panic, let's just print debug message and set SBI_NEED_FSCK to
  39 give a hint to fsck for latter repairing.
  40
  41 Signed-off-by: Chao Yu <yuchao0@huawei.com>
  42 [Jaegeuk Kim: fix build warning and add unlikely]
  43 Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
  44 Signed-off-by: Sasha Levin <sashal@kernel.org>
  45 ---
  46  fs/f2fs/f2fs.h | 12 ++++++++++--
  47  1 file changed, 10 insertions(+), 2 deletions(-)
  48
  49 diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
  50 index a4b6eacf22ea..64f970cca1b4 100644
  51 --- a/fs/f2fs/f2fs.h
  52 +++ b/fs/f2fs/f2fs.h
  53 @@ -1744,6 +1744,7 @@ enospc:
  54         return -ENOSPC;
  55  }
  56
  57 +void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...);
  58  static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
  59                                                 struct inode *inode,
  60                                                 block_t count)
  61 @@ -1752,13 +1753,21 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
  62
  63         spin_lock(&sbi->stat_lock);
  64         f2fs_bug_on(sbi, sbi->total_valid_block_count < (block_t) count);
  65 -       f2fs_bug_on(sbi, inode->i_blocks < sectors);
  66         sbi->total_valid_block_count -= (block_t)count;
  67         if (sbi->reserved_blocks &&
  68                 sbi->current_reserved_blocks < sbi->reserved_blocks)
  69                 sbi->current_reserved_blocks = min(sbi->reserved_blocks,
  70                                         sbi->current_reserved_blocks + count);
  71         spin_unlock(&sbi->stat_lock);
  72 +       if (unlikely(inode->i_blocks < sectors)) {
  73 +               f2fs_msg(sbi->sb, KERN_WARNING,
  74 +                       "Inconsistent i_blocks, ino:%lu, iblocks:%llu, sectors:%llu",
  75 +                       inode->i_ino,
  76 +                       (unsigned long long)inode->i_blocks,
  77 +                       (unsigned long long)sectors);
  78 +               set_sbi_flag(sbi, SBI_NEED_FSCK);
  79 +               return;
  80 +       }
  81         f2fs_i_blocks_write(inode, count, false, true);
  82  }
  83
  84 @@ -2727,7 +2736,6 @@ static inline void f2fs_update_iostat(struct f2fs_sb_info *sbi,
  85
  86  bool f2fs_is_valid_blkaddr(struct f2fs_sb_info *sbi,
  87                                         block_t blkaddr, int type);
  88 -void f2fs_msg(struct super_block *sb, const char *level, const char *fmt, ...);
  89  static inline void verify_blkaddr(struct f2fs_sb_info *sbi,
  90                                         block_t blkaddr, int type)
  91  {
  92 --
  93 2.20.1
  94