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| author | Zhihao Cheng <chengzhihao1@huawei.com> | 2023-03-08 06:26:43 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-17 10:45:07 +0300 |
| commit | 3f00c476da8fe7c4c34ea16abb55d74127120413 (patch) | |
| tree | 3fd956e6262d8c9a0c6afb42d5597cf5a2de433e | |
| parent | a9bd94f67b27739bbe8583c52256502bd4cc7e83 (diff) | |
| download | linux-3f00c476da8fe7c4c34ea16abb55d74127120413.tar.xz | |
ext4: zero i_disksize when initializing the bootloader inode
commit f5361da1e60d54ec81346aee8e3d8baf1be0b762 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/ext4/ioctl.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 240d792db9f7..53bdc67a815f 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -180,6 +180,7 @@ 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); |