From: Carlos Llamas <cmllamas@xxxxxxxxxx> commit f941c51eeac7ebe0f8ec30943bf78e7f60aad039 upstream. Support for cryptoloop was deleted in commit 47e9624616c8 ("block: remove support for cryptoloop and the xor transfer"), making the usage of loop_info->lo_encrypt_type obsolete. However, this member was also removed from the compat_loop_info definition and this breaks userspace ioctl calls for 32-bit binaries and CONFIG_COMPAT=y. This patch restores the compat_loop_info->lo_encrypt_type member and marks it obsolete as well as in the uapi header definitions. Fixes: 47e9624616c8 ("block: remove support for cryptoloop and the xor transfer") Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/r/20220329201815.1347500-1-cmllamas@xxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/loop.c | 1 + include/uapi/linux/loop.h | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1603,6 +1603,7 @@ struct compat_loop_info { compat_ulong_t lo_inode; /* ioctl r/o */ compat_dev_t lo_rdevice; /* ioctl r/o */ compat_int_t lo_offset; + compat_int_t lo_encrypt_type; /* obsolete, ignored */ compat_int_t lo_encrypt_key_size; /* ioctl w/o */ compat_int_t lo_flags; /* ioctl r/o */ char lo_name[LO_NAME_SIZE]; --- a/include/uapi/linux/loop.h +++ b/include/uapi/linux/loop.h @@ -45,7 +45,7 @@ struct loop_info { unsigned long lo_inode; /* ioctl r/o */ __kernel_old_dev_t lo_rdevice; /* ioctl r/o */ int lo_offset; - int lo_encrypt_type; + int lo_encrypt_type; /* obsolete, ignored */ int lo_encrypt_key_size; /* ioctl w/o */ int lo_flags; char lo_name[LO_NAME_SIZE]; @@ -61,7 +61,7 @@ struct loop_info64 { __u64 lo_offset; __u64 lo_sizelimit;/* bytes, 0 == max available */ __u32 lo_number; /* ioctl r/o */ - __u32 lo_encrypt_type; + __u32 lo_encrypt_type; /* obsolete, ignored */ __u32 lo_encrypt_key_size; /* ioctl w/o */ __u32 lo_flags; __u8 lo_file_name[LO_NAME_SIZE]; Patches currently in stable-queue which might be from cmllamas@xxxxxxxxxx are queue-5.16/loop-fix-ioctl-calls-using-compat_loop_info.patch