2022-03-29 23:00:14

by Carlos Llamas

[permalink] [raw]
Subject: [PATCH] loop: fix ioctl calls using compat_loop_info

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 <[email protected]>
---
drivers/block/loop.c | 1 +
include/uapi/linux/loop.h | 4 ++--
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3e636a75c83a..a58595f5ee2c 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1591,6 +1591,7 @@ 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];
diff --git a/include/uapi/linux/loop.h b/include/uapi/linux/loop.h
index 24a1c45bd1ae..98e60801195e 100644
--- 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];
--
2.35.1.1021.g381101b075-goog


2022-03-31 04:30:09

by Jens Axboe

[permalink] [raw]
Subject: Re: [PATCH] loop: fix ioctl calls using compat_loop_info

On Tue, 29 Mar 2022 20:18:15 +0000, Carlos Llamas wrote:
> 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.
>
> [...]

Applied, thanks!

[1/1] loop: fix ioctl calls using compat_loop_info
commit: f941c51eeac7ebe0f8ec30943bf78e7f60aad039

Best regards,
--
Jens Axboe


2022-03-31 04:46:55

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] loop: fix ioctl calls using compat_loop_info

On Tue, Mar 29, 2022 at 08:18:15PM +0000, Carlos Llamas wrote:
> 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 <[email protected]>

Ooops. The fix looks good:

Reviewed-by: Christoph Hellwig <[email protected]>