The patch titled
Subject: ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
has been added to the -mm tree. Its filename is
ipc-check-checkpoint_restore_ns_capable-to-modify-c-r-proc-files.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/ipc-check-checkpoint_restore_ns_capable-to-modify-c-r-proc-files.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/ipc-check-checkpoint_restore_ns_capable-to-modify-c-r-proc-files.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Michal Clapinski <mclapinski@xxxxxxxxxx>
Subject: ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
This commit removes the requirement to be root to modify sem_next_id,
msg_next_id and shm_next_id and checks checkpoint_restore_ns_capable
instead.
Since those files are specific to the IPC namespace, there is no reason
they should require root privileges. This is similar to ns_last_pid,
which also only checks checkpoint_restore_ns_capable.
Link: https://lkml.kernel.org/r/20210916163717.3179496-1-mclapinski@xxxxxxxxxx
Signed-off-by: Michal Clapinski <mclapinski@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/ipc_sysctl.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
--- a/ipc/ipc_sysctl.c~ipc-check-checkpoint_restore_ns_capable-to-modify-c-r-proc-files
+++ a/ipc/ipc_sysctl.c
@@ -104,6 +104,19 @@ static int proc_ipc_sem_dointvec(struct
return ret;
}
+#ifdef CONFIG_CHECKPOINT_RESTORE
+static int proc_ipc_dointvec_minmax_checkpoint_restore(struct ctl_table *table,
+ int write, void *buffer, size_t *lenp, loff_t *ppos)
+{
+ struct user_namespace *user_ns = current->nsproxy->ipc_ns->user_ns;
+
+ if (write && !checkpoint_restore_ns_capable(user_ns))
+ return -EPERM;
+
+ return proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos);
+}
+#endif
+
#else
#define proc_ipc_doulongvec_minmax NULL
#define proc_ipc_dointvec NULL
@@ -111,6 +124,9 @@ static int proc_ipc_sem_dointvec(struct
#define proc_ipc_dointvec_minmax_orphans NULL
#define proc_ipc_auto_msgmni NULL
#define proc_ipc_sem_dointvec NULL
+#ifdef CONFIG_CHECKPOINT_RESTORE
+#define proc_ipc_dointvec_minmax_checkpoint_restore NULL
+#endif /* CONFIG_CHECKPOINT_RESTORE */
#endif
int ipc_mni = IPCMNI;
@@ -198,8 +214,8 @@ static struct ctl_table ipc_kern_table[]
.procname = "sem_next_id",
.data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
- .mode = 0644,
- .proc_handler = proc_ipc_dointvec_minmax,
+ .mode = 0666,
+ .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
@@ -207,8 +223,8 @@ static struct ctl_table ipc_kern_table[]
.procname = "msg_next_id",
.data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
- .mode = 0644,
- .proc_handler = proc_ipc_dointvec_minmax,
+ .mode = 0666,
+ .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
@@ -216,8 +232,8 @@ static struct ctl_table ipc_kern_table[]
.procname = "shm_next_id",
.data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id,
.maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
- .mode = 0644,
- .proc_handler = proc_ipc_dointvec_minmax,
+ .mode = 0666,
+ .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_INT_MAX,
},
_
Patches currently in -mm which might be from mclapinski@xxxxxxxxxx are
ipc-check-checkpoint_restore_ns_capable-to-modify-c-r-proc-files.patch
