4.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Amir Goldstein <[email protected]> commit 8f97d1e99149a7f1aa19e47a51b09764382a482e upstream. 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: d1d04ef8572b ("ovl: stack file ops") Cc: <[email protected]> # v4.19 Signed-off-by: Amir Goldstein <[email protected]> Signed-off-by: Miklos Szeredi <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/ioctl.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -669,6 +669,9 @@ int do_vfs_ioctl(struct file *filp, unsi 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:
