diff options
| author | OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> | 2017-03-09 16:17:37 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-07-04 11:51:39 +0200 |
| commit | c377e81063ef9f0896d0504d6d5e0bcaed087efc (patch) | |
| tree | 8b565d55263b71bc89c3a39c7b0c8a8c1c002fd0 | |
| parent | 5d8eb4280b411df96dfd523628a5d669ac670fe3 (diff) | |
fat: fix using uninitialized fields of fat_inode/fsinfo_inode
commit c0d0e351285161a515396b7b1ee53ec9ffd97e3c upstream.
Recently fallocate patch was merged and it uses
MSDOS_I(inode)->mmu_private at fat_evict_inode(). However,
fat_inode/fsinfo_inode that was introduced in past didn't initialize
MSDOS_I(inode) properly.
With those combinations, it became the cause of accessing random entry
in FAT area.
Link: http://lkml.kernel.org/r/87pohrj4i8.fsf@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Moreno Bartalucci <moreno.bartalucci@tecnorama.it>
Tested-by: Moreno Bartalucci <moreno.bartalucci@tecnorama.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | fs/fat/inode.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c index e69f87abd..09228fd7a 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1232,6 +1232,16 @@ out: return 0; } +static void fat_dummy_inode_init(struct inode *inode) +{ + /* Initialize this dummy inode to work as no-op. */ + MSDOS_I(inode)->mmu_private = 0; + MSDOS_I(inode)->i_start = 0; + MSDOS_I(inode)->i_logstart = 0; + MSDOS_I(inode)->i_attrs = 0; + MSDOS_I(inode)->i_pos = 0; +} + static int fat_read_root(struct inode *inode) { struct super_block *sb = inode->i_sb; @@ -1551,12 +1561,13 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, fat_inode = new_inode(sb); if (!fat_inode) goto out_fail; - MSDOS_I(fat_inode)->i_pos = 0; + fat_dummy_inode_init(fat_inode); sbi->fat_inode = fat_inode; fsinfo_inode = new_inode(sb); if (!fsinfo_inode) goto out_fail; + fat_dummy_inode_init(fsinfo_inode); fsinfo_inode->i_ino = MSDOS_FSINFO_INO; sbi->fsinfo_inode = fsinfo_inode; insert_inode_hash(fsinfo_inode); |