Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 63e87367 authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Greg Kroah-Hartman
Browse files

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: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: default avatarMoreno Bartalucci <moreno.bartalucci@tecnorama.it>
Tested-by: default avatarMoreno Bartalucci <moreno.bartalucci@tecnorama.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 16ace910

fs/fat/inode.c

+12 −1
Original line number Diff line number Diff line
@@ -1359,6 +1359,16 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, 
	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 msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
@@ -1803,12 +1813,13 @@ 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);