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authorZhihao Cheng <chengzhihao1@huawei.com>2023-03-08 06:26:43 +0300
committerTheodore Ts'o <tytso@mit.edu>2023-03-11 08:44:24 +0300
commitf5361da1e60d54ec81346aee8e3d8baf1be0b762 (patch)
treecd09d3a35b133452441651a162bb61ca3616d7f6 /fs
parentf57886ca1606ba74cc4ec4eb5cbf073934ffa559 (diff)
downloadlinux-f5361da1e60d54ec81346aee8e3d8baf1be0b762.tar.xz
ext4: zero i_disksize when initializing the bootloader inode
If the boot loader inode has never been used before, the EXT4_IOC_SWAP_BOOT inode will initialize it, including setting the i_size to 0. However, if the "never before used" boot loader has a non-zero i_size, then i_disksize will be non-zero, and the inconsistency between i_size and i_disksize can trigger a kernel warning: WARNING: CPU: 0 PID: 2580 at fs/ext4/file.c:319 CPU: 0 PID: 2580 Comm: bb Not tainted 6.3.0-rc1-00004-g703695902cfa RIP: 0010:ext4_file_write_iter+0xbc7/0xd10 Call Trace: vfs_write+0x3b1/0x5c0 ksys_write+0x77/0x160 __x64_sys_write+0x22/0x30 do_syscall_64+0x39/0x80 Reproducer: 1. create corrupted image and mount it: mke2fs -t ext4 /tmp/foo.img 200 debugfs -wR "sif <5> size 25700" /tmp/foo.img mount -t ext4 /tmp/foo.img /mnt cd /mnt echo 123 > file 2. Run the reproducer program: posix_memalign(&buf, 1024, 1024) fd = open("file", O_RDWR | O_DIRECT); ioctl(fd, EXT4_IOC_SWAP_BOOT); write(fd, buf, 1024); Fix this by setting i_disksize as well as i_size to zero when initiaizing the boot loader inode. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217159 Cc: stable@kernel.org Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Link: https://lore.kernel.org/r/20230308032643.641113-1-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs')
-rw-r--r--fs/ext4/ioctl.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 2e8c34036313..cc17205f7f49 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -431,6 +431,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
ei_bl->i_flags = 0;
inode_set_iversion(inode_bl, 1);
i_size_write(inode_bl, 0);
+ EXT4_I(inode_bl)->i_disksize = inode_bl->i_size;
inode_bl->i_mode = S_IFREG;
if (ext4_has_feature_extents(sb)) {
ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);