zfs send -I is broken with binary from 2.3.2 and kernel module 2.3.1

[brong]

System information

Type	Version/Name
Distribution Name	Debian
Distribution Version	Bookworm
Kernel Version	6.1.0-32-amd64
Architecture	amd64
OpenZFS Version	2.3.2

Describe the problem you're observing

When zfs userland tools were upgraded to 2.3.2 but kernel was still on 2.3.1, zfs send -I failed to work, though zfs send -i worked still.

Describe how to reproduce the problem

Boot with 2.3.1 kernel module and 2.3.2 userland. Here's an example of it failing on a machine with the new userland before a reboot.

[fastmail root(brong)@phl-imap-02 ~] # zfs create -o mountpoint=/mnt/test tank/test
[fastmail root(brong)@phl-imap-02 ~] # zfs snapshot tank/test@a
[fastmail root(brong)@phl-imap-02 ~] # touch /mnt/test/hi
[fastmail root(brong)@phl-imap-02 ~] # zfs snapshot tank/test@b
[fastmail root(brong)@phl-imap-02 ~] # zfs send -i @a tank/test@b > /dev/null
[fastmail root(brong)@phl-imap-02 ~] # zfs send -I @a tank/test@b > /dev/null
warning: cannot send 'tank/test@b': Invalid argument
[fastmail root(brong)@phl-imap-02 ~] [1] # zfs version
zfs-2.3.2-103796
zfs-kmod-2.3.1-103094
[fastmail root(brong)@phl-imap-02 ~] # uname -a
Linux phl-imap-02 6.1.0-32-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.129-1 (2025-03-06) x86_64 GNU/Linux

and and example of it working on a different host where the kernel has already been upgraded.

[fastmail root(brong)@stl-imap-09 ~] # zfs create -o mountpoint=/mnt/test tank/test
[fastmail root(brong)@stl-imap-09 ~] # zfs snapshot tank/test@a
[fastmail root(brong)@stl-imap-09 ~] # touch /mnt/test/hi
[fastmail root(brong)@stl-imap-09 ~] # zfs snapshot tank/test@b
[fastmail root(brong)@stl-imap-09 ~] # zfs send -i @a tank/test@b > /dev/null
[fastmail root(brong)@stl-imap-09 ~] # zfs send -I @a tank/test@b > /dev/null
[fastmail root(brong)@stl-imap-09 ~] # zfs version
zfs-2.3.2-103796
zfs-kmod-2.3.2-103796
[fastmail root(brong)@stl-imap-09 ~] # uname -a
Linux stl-imap-09 6.12.22+bpo-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.12.22-1~bpo12+1 (2025-04-25) x86_64 GNU/Linux

Include any warning/errors/backtraces from the system logs

[robn]

There was an unintended ABI break in 2.3.1 (#16938), which was reverted in 2.3.2 (#17137), so 2.3.1 is the odd one out here.

[brong]

We've now rebooted all the machines that do snapshots, so everything is on 2.3.2 both kernel and userland now where we're doing snapshots.