diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-03 15:54:57 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-06-03 15:54:57 -0700 |
commit | 1888e9b4bb78c88514b24ecafa9e4e4faf761747 (patch) | |
tree | be6e177776100fd835059c5afb91096458af5405 /ipc/mq_sysctl.c | |
parent | 07953c54a10567e484cefd8f8c782025dc68b3b1 (diff) | |
parent | 38cd5b12b7854941ede1954cf5a2393eb94b5d37 (diff) |
Merge tag 'per-namespace-ipc-sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull ipc sysctl namespace updates from Eric Biederman:
"This updates the ipc sysctls so that they are fundamentally per ipc
namespace. Previously these sysctls depended upon a hack to simulate
being per ipc namespace by looking up the ipc namespace in read or
write. With this set of changes the ipc sysctls are registered per ipc
namespace and open looks up the ipc namespace.
Not only does this series of changes ensure the traditional binding at
open time happens, but it sets a foundation for being able to relax
the permission checks to allow a user namspace root to change the ipc
sysctls for an ipc namespace that the user namespace root requires. To
do this requires the ipc namespace to be known at open time"
* tag 'per-namespace-ipc-sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ipc: Remove extra braces
ipc: Check permissions for checkpoint_restart sysctls at open time
ipc: Remove extra1 field abuse to pass ipc namespace
ipc: Use the same namespace to modify and validate
ipc: Store ipc sysctls in the ipc namespace
ipc: Store mqueue sysctls in the ipc namespace
Diffstat (limited to 'ipc/mq_sysctl.c')
-rw-r--r-- | ipc/mq_sysctl.c | 121 |
1 files changed, 66 insertions, 55 deletions
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c index 72a92a08c848..fbf6a8b93a26 100644 --- a/ipc/mq_sysctl.c +++ b/ipc/mq_sysctl.c @@ -9,39 +9,9 @@ #include <linux/ipc_namespace.h> #include <linux/sysctl.h> -#ifdef CONFIG_PROC_SYSCTL -static void *get_mq(struct ctl_table *table) -{ - char *which = table->data; - struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; - which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns; - return which; -} - -static int proc_mq_dointvec(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) -{ - struct ctl_table mq_table; - memcpy(&mq_table, table, sizeof(mq_table)); - mq_table.data = get_mq(table); - - return proc_dointvec(&mq_table, write, buffer, lenp, ppos); -} - -static int proc_mq_dointvec_minmax(struct ctl_table *table, int write, - void *buffer, size_t *lenp, loff_t *ppos) -{ - struct ctl_table mq_table; - memcpy(&mq_table, table, sizeof(mq_table)); - mq_table.data = get_mq(table); - - return proc_dointvec_minmax(&mq_table, write, buffer, - lenp, ppos); -} -#else -#define proc_mq_dointvec NULL -#define proc_mq_dointvec_minmax NULL -#endif +#include <linux/stat.h> +#include <linux/capability.h> +#include <linux/slab.h> static int msg_max_limit_min = MIN_MSGMAX; static int msg_max_limit_max = HARD_MSGMAX; @@ -55,14 +25,14 @@ static struct ctl_table mq_sysctls[] = { .data = &init_ipc_ns.mq_queues_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec, + .proc_handler = proc_dointvec, }, { .procname = "msg_max", .data = &init_ipc_ns.mq_msg_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec_minmax, + .proc_handler = proc_dointvec_minmax, .extra1 = &msg_max_limit_min, .extra2 = &msg_max_limit_max, }, @@ -71,7 +41,7 @@ static struct ctl_table mq_sysctls[] = { .data = &init_ipc_ns.mq_msgsize_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec_minmax, + .proc_handler = proc_dointvec_minmax, .extra1 = &msg_maxsize_limit_min, .extra2 = &msg_maxsize_limit_max, }, @@ -80,7 +50,7 @@ static struct ctl_table mq_sysctls[] = { .data = &init_ipc_ns.mq_msg_default, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec_minmax, + .proc_handler = proc_dointvec_minmax, .extra1 = &msg_max_limit_min, .extra2 = &msg_max_limit_max, }, @@ -89,32 +59,73 @@ static struct ctl_table mq_sysctls[] = { .data = &init_ipc_ns.mq_msgsize_default, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_mq_dointvec_minmax, + .proc_handler = proc_dointvec_minmax, .extra1 = &msg_maxsize_limit_min, .extra2 = &msg_maxsize_limit_max, }, {} }; -static struct ctl_table mq_sysctl_dir[] = { - { - .procname = "mqueue", - .mode = 0555, - .child = mq_sysctls, - }, - {} -}; +static struct ctl_table_set *set_lookup(struct ctl_table_root *root) +{ + return ¤t->nsproxy->ipc_ns->mq_set; +} -static struct ctl_table mq_sysctl_root[] = { - { - .procname = "fs", - .mode = 0555, - .child = mq_sysctl_dir, - }, - {} +static int set_is_seen(struct ctl_table_set *set) +{ + return ¤t->nsproxy->ipc_ns->mq_set == set; +} + +static struct ctl_table_root set_root = { + .lookup = set_lookup, }; -struct ctl_table_header *mq_register_sysctl_table(void) +bool setup_mq_sysctls(struct ipc_namespace *ns) { - return register_sysctl_table(mq_sysctl_root); + struct ctl_table *tbl; + + setup_sysctl_set(&ns->mq_set, &set_root, set_is_seen); + + tbl = kmemdup(mq_sysctls, sizeof(mq_sysctls), GFP_KERNEL); + if (tbl) { + int i; + + for (i = 0; i < ARRAY_SIZE(mq_sysctls); i++) { + if (tbl[i].data == &init_ipc_ns.mq_queues_max) + tbl[i].data = &ns->mq_queues_max; + + else if (tbl[i].data == &init_ipc_ns.mq_msg_max) + tbl[i].data = &ns->mq_msg_max; + + else if (tbl[i].data == &init_ipc_ns.mq_msgsize_max) + tbl[i].data = &ns->mq_msgsize_max; + + else if (tbl[i].data == &init_ipc_ns.mq_msg_default) + tbl[i].data = &ns->mq_msg_default; + + else if (tbl[i].data == &init_ipc_ns.mq_msgsize_default) + tbl[i].data = &ns->mq_msgsize_default; + else + tbl[i].data = NULL; + } + + ns->mq_sysctls = __register_sysctl_table(&ns->mq_set, "fs/mqueue", tbl); + } + if (!ns->mq_sysctls) { + kfree(tbl); + retire_sysctl_set(&ns->mq_set); + return false; + } + + return true; +} + +void retire_mq_sysctls(struct ipc_namespace *ns) +{ + struct ctl_table *tbl; + + tbl = ns->mq_sysctls->ctl_table_arg; + unregister_sysctl_table(ns->mq_sysctls); + retire_sysctl_set(&ns->mq_set); + kfree(tbl); } |