Commit 8f97d1e9 authored Oct 11, 2018 by Amir Goldstein Committed by Miklos Szeredi Oct 26, 2018

vfs: fix FIGETBSZ ioctl on an overlayfs file



Some anon_bdev filesystems (e.g. overlayfs, ceph) don't have s_blocksize
set. Returning zero from FIGETBSZ ioctl results in a Floating point
exception from the e2fsprogs utility filefrag, which divides the size of
the file with the value returned by FIGETBSZ.

Fix the interface by returning -EINVAL for these filesystems.

Fixes: d1d04ef8 ("ovl: stack file ops")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent 1f244dc5

fs/ioctl.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -669,6 +669,9 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
		return ioctl_fiemap(filp, arg);

		case FIGETBSZ:
		/* anon_bdev filesystems may not have a block size */
		if (!inode->i_sb->s_blocksize)
		return -EINVAL;
		return put_user(inode->i_sb->s_blocksize, argp);

		case FICLONE:

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