The patch titled Subject: fat: fix uninit-memory access for partial initialized inode has been added to the -mm tree. Its filename is fat-fix-uninit-memory-access-for-partial-initialized-inode.patch

This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/fat-fix-uninit-memory-access-for-pa... and later at http://ozlabs.org/~akpm/mmotm/broken-out/fat-fix-uninit-memory-access-for-pa...

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------------------------------------------------------ From: OGAWA Hirofumi hirofumi@mail.parknet.co.jp Subject: fat: fix uninit-memory access for partial initialized inode

When get an error in the middle of reading an inode, some fields in the inode might be still not initialized. And then the evict_inode path may access those fields via iput().

To fix, this makes sure that inode fields are initialized.

Link: http://lkml.kernel.org/r/871rqnreqx.fsf@mail.parknet.co.jp Reported-by: syzbot+9d82b8de2992579da5d0@syzkaller.appspotmail.com Signed-off-by: OGAWA Hirofumi hirofumi@mail.parknet.co.jp Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/fat/inode.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-)

--- a/fs/fat/inode.c~fat-fix-uninit-memory-access-for-partial-initialized-inode +++ a/fs/fat/inode.c @@ -750,6 +750,13 @@ static struct inode *fat_alloc_inode(str return NULL;

init_rwsem(&ei->truncate_lock); + /* Zeroing to allow iput() even if partial initialized inode. */ + ei->mmu_private = 0; + ei->i_start = 0; + ei->i_logstart = 0; + ei->i_attrs = 0; + ei->i_pos = 0; + return &ei->vfs_inode; }

@@ -1374,16 +1381,6 @@ 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 msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); @@ -1844,13 +1841,11 @@ int fat_fill_super(struct super_block *s fat_inode = new_inode(sb); if (!fat_inode) goto out_fail; - 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); _

Patches currently in -mm which might be from hirofumi@mail.parknet.co.jp are

fat-fix-uninit-memory-access-for-partial-initialized-inode.patch