Commit dd141a49 authored by Alexey Gladkov's avatar Alexey Gladkov Committed by Eric W. Biederman
Browse files

ipc: Remove extra1 field abuse to pass ipc namespace 

Eric Biederman pointed out that using .extra1 to pass ipc namespace
looks like an ugly hack and there is a better solution. We can get the
ipc_namespace using the .data field.

Link: https://lore.kernel.org/lkml/87czib9g38.fsf@email.froward.int.ebiederm.org/


Fixes: 1f5c135e ("ipc: Store ipc sysctls in the ipc namespace")
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarAlexey Gladkov <legion@kernel.org>
Link: https://lkml.kernel.org/r/93df64a8fe93ba20ebbe1d9f8eda484b2f325426.1651584847.git.legion@kernel.org


Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent def7343f

ipc/ipc_sysctl.c

+7 −17
Original line number Diff line number Diff line
@@ -19,16 +19,11 @@ 
static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,

		void *buffer, size_t *lenp, loff_t *ppos)

{

	struct ipc_namespace *ns = table->extra1;

	struct ctl_table ipc_table;

	struct ipc_namespace *ns =

		container_of(table->data, struct ipc_namespace, shm_rmid_forced);

	int err;



	memcpy(&ipc_table, table, sizeof(ipc_table));



	ipc_table.extra1 = SYSCTL_ZERO;

	ipc_table.extra2 = SYSCTL_ONE;



	err = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);

	err = proc_dointvec_minmax(table, write, buffer, lenp, ppos);



	if (err < 0)

		return err;
@@ -55,15 +50,10 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write, 
static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,

	void *buffer, size_t *lenp, loff_t *ppos)

{

	struct ipc_namespace *ns = table->extra1;

	struct ctl_table ipc_table;

	struct ipc_namespace *ns =

		container_of(table->data, struct ipc_namespace, sem_ctls);

	int ret, semmni;



	memcpy(&ipc_table, table, sizeof(ipc_table));



	ipc_table.extra1 = NULL;

	ipc_table.extra2 = NULL;



	semmni = ns->sem_ctls[3];

	ret = proc_dointvec(table, write, buffer, lenp, ppos);
@@ -131,6 +121,8 @@ static struct ctl_table ipc_sysctls[] = { 
		.maxlen		= sizeof(init_ipc_ns.shm_rmid_forced),

		.mode		= 0644,

		.proc_handler	= proc_ipc_dointvec_minmax_orphans,

		.extra1		= SYSCTL_ZERO,

		.extra2		= SYSCTL_ONE,

	},

	{

		.procname	= "msgmax",
@@ -237,7 +229,6 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns) 


			} else if (tbl[i].data == &init_ipc_ns.shm_rmid_forced) {

				tbl[i].data = &ns->shm_rmid_forced;

				tbl[i].extra1 = ns;



			} else if (tbl[i].data == &init_ipc_ns.msg_ctlmax) {

				tbl[i].data = &ns->msg_ctlmax;
@@ -250,7 +241,6 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns) 


			} else if (tbl[i].data == &init_ipc_ns.sem_ctls) {

				tbl[i].data = &ns->sem_ctls;

				tbl[i].extra1 = ns;

#ifdef CONFIG_CHECKPOINT_RESTORE

			} else if (tbl[i].data == &init_ipc_ns.ids[IPC_SEM_IDS].next_id) {

				tbl[i].data = &ns->ids[IPC_SEM_IDS].next_id;