[PATCH 5.10 096/289] f2fs: fix compat F2FS_IOC_{MOVE,GARBAGE_COLLECT}_RANGE

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 11:30:57 EST


From: Chao Yu <yuchao0@xxxxxxxxxx>

[ Upstream commit 34178b1bc4b5c936eab3adb4835578093095a571 ]

Eric reported a ioctl bug in below link:

https://lore.kernel.org/linux-f2fs-devel/20201103032234.GB2875@sol.localdomain/

That said, on some 32-bit architectures, u64 has only 32-bit alignment,
notably i386 and x86_32, so that size of struct f2fs_gc_range compiled
in x86_32 is 20 bytes, however the size in x86_64 is 24 bytes, binary
compiled in x86_32 can not call F2FS_IOC_GARBAGE_COLLECT_RANGE successfully
due to mismatched value of ioctl command in between binary and f2fs
module, similarly, F2FS_IOC_MOVE_RANGE will fail too.

In this patch we introduce two ioctls for compatibility of above special
32-bit binary:
- F2FS_IOC32_GARBAGE_COLLECT_RANGE
- F2FS_IOC32_MOVE_RANGE

Reported-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/f2fs/file.c | 137 +++++++++++++++++++++++++++++++++++++------------
1 file changed, 104 insertions(+), 33 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 28f0bde38806..6850fb2081c8 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2496,26 +2496,19 @@ out:
return ret;
}

-static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
+static int __f2fs_ioc_gc_range(struct file *filp, struct f2fs_gc_range *range)
{
- struct inode *inode = file_inode(filp);
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
- struct f2fs_gc_range range;
+ struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
u64 end;
int ret;

if (!capable(CAP_SYS_ADMIN))
return -EPERM;
-
- if (copy_from_user(&range, (struct f2fs_gc_range __user *)arg,
- sizeof(range)))
- return -EFAULT;
-
if (f2fs_readonly(sbi->sb))
return -EROFS;

- end = range.start + range.len;
- if (end < range.start || range.start < MAIN_BLKADDR(sbi) ||
+ end = range->start + range->len;
+ if (end < range->start || range->start < MAIN_BLKADDR(sbi) ||
end >= MAX_BLKADDR(sbi))
return -EINVAL;

@@ -2524,7 +2517,7 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
return ret;

do_more:
- if (!range.sync) {
+ if (!range->sync) {
if (!down_write_trylock(&sbi->gc_lock)) {
ret = -EBUSY;
goto out;
@@ -2533,20 +2526,30 @@ do_more:
down_write(&sbi->gc_lock);
}

- ret = f2fs_gc(sbi, range.sync, true, GET_SEGNO(sbi, range.start));
+ ret = f2fs_gc(sbi, range->sync, true, GET_SEGNO(sbi, range->start));
if (ret) {
if (ret == -EBUSY)
ret = -EAGAIN;
goto out;
}
- range.start += BLKS_PER_SEC(sbi);
- if (range.start <= end)
+ range->start += BLKS_PER_SEC(sbi);
+ if (range->start <= end)
goto do_more;
out:
mnt_drop_write_file(filp);
return ret;
}

+static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
+{
+ struct f2fs_gc_range range;
+
+ if (copy_from_user(&range, (struct f2fs_gc_range __user *)arg,
+ sizeof(range)))
+ return -EFAULT;
+ return __f2fs_ioc_gc_range(filp, &range);
+}
+
static int f2fs_ioc_write_checkpoint(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -2883,9 +2886,9 @@ out:
return ret;
}

-static int f2fs_ioc_move_range(struct file *filp, unsigned long arg)
+static int __f2fs_ioc_move_range(struct file *filp,
+ struct f2fs_move_range *range)
{
- struct f2fs_move_range range;
struct fd dst;
int err;

@@ -2893,11 +2896,7 @@ static int f2fs_ioc_move_range(struct file *filp, unsigned long arg)
!(filp->f_mode & FMODE_WRITE))
return -EBADF;

- if (copy_from_user(&range, (struct f2fs_move_range __user *)arg,
- sizeof(range)))
- return -EFAULT;
-
- dst = fdget(range.dst_fd);
+ dst = fdget(range->dst_fd);
if (!dst.file)
return -EBADF;

@@ -2910,8 +2909,8 @@ static int f2fs_ioc_move_range(struct file *filp, unsigned long arg)
if (err)
goto err_out;

- err = f2fs_move_file_range(filp, range.pos_in, dst.file,
- range.pos_out, range.len);
+ err = f2fs_move_file_range(filp, range->pos_in, dst.file,
+ range->pos_out, range->len);

mnt_drop_write_file(filp);
if (err)
@@ -2925,6 +2924,16 @@ err_out:
return err;
}

+static int f2fs_ioc_move_range(struct file *filp, unsigned long arg)
+{
+ struct f2fs_move_range range;
+
+ if (copy_from_user(&range, (struct f2fs_move_range __user *)arg,
+ sizeof(range)))
+ return -EFAULT;
+ return __f2fs_ioc_move_range(filp, &range);
+}
+
static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -3961,13 +3970,8 @@ err:
return ret;
}

-long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
- return -EIO;
- if (!f2fs_is_checkpoint_ready(F2FS_I_SB(file_inode(filp))))
- return -ENOSPC;
-
switch (cmd) {
case FS_IOC_GETFLAGS:
return f2fs_ioc_getflags(filp, arg);
@@ -4054,6 +4058,16 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
}
}

+long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(filp)))))
+ return -EIO;
+ if (!f2fs_is_checkpoint_ready(F2FS_I_SB(file_inode(filp))))
+ return -ENOSPC;
+
+ return __f2fs_ioctl(filp, cmd, arg);
+}
+
static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
@@ -4176,8 +4190,63 @@ out:
}

#ifdef CONFIG_COMPAT
+struct compat_f2fs_gc_range {
+ u32 sync;
+ compat_u64 start;
+ compat_u64 len;
+};
+#define F2FS_IOC32_GARBAGE_COLLECT_RANGE _IOW(F2FS_IOCTL_MAGIC, 11,\
+ struct compat_f2fs_gc_range)
+
+static int f2fs_compat_ioc_gc_range(struct file *file, unsigned long arg)
+{
+ struct compat_f2fs_gc_range __user *urange;
+ struct f2fs_gc_range range;
+ int err;
+
+ urange = compat_ptr(arg);
+ err = get_user(range.sync, &urange->sync);
+ err |= get_user(range.start, &urange->start);
+ err |= get_user(range.len, &urange->len);
+ if (err)
+ return -EFAULT;
+
+ return __f2fs_ioc_gc_range(file, &range);
+}
+
+struct compat_f2fs_move_range {
+ u32 dst_fd;
+ compat_u64 pos_in;
+ compat_u64 pos_out;
+ compat_u64 len;
+};
+#define F2FS_IOC32_MOVE_RANGE _IOWR(F2FS_IOCTL_MAGIC, 9, \
+ struct compat_f2fs_move_range)
+
+static int f2fs_compat_ioc_move_range(struct file *file, unsigned long arg)
+{
+ struct compat_f2fs_move_range __user *urange;
+ struct f2fs_move_range range;
+ int err;
+
+ urange = compat_ptr(arg);
+ err = get_user(range.dst_fd, &urange->dst_fd);
+ err |= get_user(range.pos_in, &urange->pos_in);
+ err |= get_user(range.pos_out, &urange->pos_out);
+ err |= get_user(range.len, &urange->len);
+ if (err)
+ return -EFAULT;
+
+ return __f2fs_ioc_move_range(file, &range);
+}
+
long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
+ if (unlikely(f2fs_cp_error(F2FS_I_SB(file_inode(file)))))
+ return -EIO;
+ if (!f2fs_is_checkpoint_ready(F2FS_I_SB(file_inode(file))))
+ return -ENOSPC;
+
switch (cmd) {
case FS_IOC32_GETFLAGS:
cmd = FS_IOC_GETFLAGS;
@@ -4188,6 +4257,10 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC32_GETVERSION:
cmd = FS_IOC_GETVERSION;
break;
+ case F2FS_IOC32_GARBAGE_COLLECT_RANGE:
+ return f2fs_compat_ioc_gc_range(file, arg);
+ case F2FS_IOC32_MOVE_RANGE:
+ return f2fs_compat_ioc_move_range(file, arg);
case F2FS_IOC_START_ATOMIC_WRITE:
case F2FS_IOC_COMMIT_ATOMIC_WRITE:
case F2FS_IOC_START_VOLATILE_WRITE:
@@ -4205,10 +4278,8 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
case FS_IOC_GET_ENCRYPTION_NONCE:
case F2FS_IOC_GARBAGE_COLLECT:
- case F2FS_IOC_GARBAGE_COLLECT_RANGE:
case F2FS_IOC_WRITE_CHECKPOINT:
case F2FS_IOC_DEFRAGMENT:
- case F2FS_IOC_MOVE_RANGE:
case F2FS_IOC_FLUSH_DEVICE:
case F2FS_IOC_GET_FEATURES:
case FS_IOC_FSGETXATTR:
@@ -4229,7 +4300,7 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
default:
return -ENOIOCTLCMD;
}
- return f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+ return __f2fs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif

--
2.30.2