The kernel is writing an object of type __u64, so the ioctl has to be defined to _IOR(NSIO, 0x5, __u64) instead of _IO(NSIO, 0x5). Reported-by: Dmitry V. Levin <ldv@xxxxxxxxx> Link: https://lore.kernel.org/r/20240730164554.GA18486@xxxxxxxxxxxx Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- include/uapi/linux/nsfs.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h index b133211331f6..5fad3d0fcd70 100644 --- a/include/uapi/linux/nsfs.h +++ b/include/uapi/linux/nsfs.h @@ -3,6 +3,7 @@ #define __LINUX_NSFS_H #include <linux/ioctl.h> +#include <linux/types.h> #define NSIO 0xb7 @@ -16,7 +17,7 @@ /* Get owner UID (in the caller's user namespace) for a user namespace */ #define NS_GET_OWNER_UID _IO(NSIO, 0x4) /* Get the id for a mount namespace */ -#define NS_GET_MNTNS_ID _IO(NSIO, 0x5) +#define NS_GET_MNTNS_ID _IOR(NSIO, 0x5, __u64) /* Translate pid from target pid namespace into the caller's pid namespace. */ #define NS_GET_PID_FROM_PIDNS _IOR(NSIO, 0x6, int) /* Return thread-group leader id of pid in the callers pid namespace. */ -- 2.43.0 --czhavtllv27b4av2--
