Anatoly Trosinenko <anatoly.trosine...@gmail.com> writes:
> Description:
>
> Writing to some file on a broken VFAT partition causes kernel bug
Thanks. This patch should fix this issue.
--
OGAWA Hirofumi <hirof...@mail.parknet.co.jp>
[PATCH] fat: Use fat_fs_error() instead of BUG_ON() in __fat_get_block()
If file size and FAT cluster chain is not matched (corrupted image),
we can hit BUG_ON(!phys) in __fat_get_block().
So, use fat_fs_error() instead.
Signed-off-by: OGAWA Hirofumi <hirof...@mail.parknet.co.jp>
---
fs/fat/inode.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff -puN fs/fat/inode.c~vfat-dont-bugon fs/fat/inode.c
--- linux/fs/fat/inode.c~vfat-dont-bugon 2018-06-02 20:15:04.441920069
+0900
+++ linux-hirofumi/fs/fat/inode.c 2018-06-02 20:15:04.442920067 +0900
@@ -158,8 +158,13 @@ static inline int __fat_get_block(struct
err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
if (err)
return err;
+ if (!phys) {
+ fat_fs_error(sb,
+ "invalid FAT chain (i_pos %lld, last_block %ld)",
+ MSDOS_I(inode)->i_pos, last_block);
+ return -EIO;
+ }
- BUG_ON(!phys);
BUG_ON(*max_blocks != mapped_blocks);
set_buffer_new(bh_result);
map_bh(bh_result, sb, phys);
_
