From 9b78032ccf3c6f6ce6a181a919ad710605099109 Mon Sep 17 00:00:00 2001 From: yangerkun Date: Mon, 11 Feb 2019 00:02:05 -0500 Subject: [PATCH] ext4: fix check of inode in swap_inode_boot_loader commit 67a11611e1a5211f6569044fbf8150875764d1d0 upstream. Before really do swap between inode and boot inode, something need to check to avoid invalid or not permitted operation, like does this inode has inline data. But the condition check should be protected by inode lock to avoid change while swapping. Also some other condition will not change between swapping, but there has no problem to do this under inode lock. Signed-off-by: yangerkun Signed-off-by: Theodore Ts'o [bwh: Backported to 3.16: There's no support or test for filesytem encryption] Signed-off-by: Ben Hutchings --- fs/ext4/ioctl.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a77035ec6a4d..3824f5c23d97 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -118,15 +118,6 @@ static long swap_inode_boot_loader(struct super_block *sb, struct ext4_inode_info *ei_bl; struct ext4_sb_info *sbi = EXT4_SB(sb); - if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode) || - IS_SWAPFILE(inode) || - ext4_has_inline_data(inode)) - return -EINVAL; - - if (IS_RDONLY(inode) || IS_APPEND(inode) || IS_IMMUTABLE(inode) || - !inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN)) - return -EPERM; - inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, EXT4_IGET_SPECIAL); if (IS_ERR(inode_bl)) return PTR_ERR(inode_bl); @@ -139,6 +130,19 @@ static long swap_inode_boot_loader(struct super_block *sb, * that only 1 swap_inode_boot_loader is running. */ lock_two_nondirectories(inode, inode_bl); + if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode) || + IS_SWAPFILE(inode) || + ext4_has_inline_data(inode)) { + err = -EINVAL; + goto journal_err_out; + } + + if (IS_RDONLY(inode) || IS_APPEND(inode) || IS_IMMUTABLE(inode) || + !inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto journal_err_out; + } + /* Wait for all existing dio workers */ ext4_inode_block_unlocked_dio(inode); ext4_inode_block_unlocked_dio(inode_bl);