[PATCH 13/14] security,sysctl: remove proc input checks out of sysctl handlers

From: Sasha Levin
Date: Sun Apr 29 2012 - 02:46:08 EST


Simplify sysctl handler by removing user input checks and using the callback
provided by the sysctl table.

Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
include/linux/security.h | 3 +--
kernel/sysctl.c | 3 ++-
security/min_addr.c | 11 +++--------
3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index ab0e091..3d3445c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -147,8 +147,7 @@ struct request_sock;
#define LSM_UNSAFE_NO_NEW_PRIVS 8

#ifdef CONFIG_MMU
-extern int mmap_min_addr_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos);
+extern int mmap_min_addr_handler(void);
#endif

/* security_inode_init_security callback function to write xattrs */
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f9ce79b..2104452 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1317,7 +1317,8 @@ static struct ctl_table vm_table[] = {
.data = &dac_mmap_min_addr,
.maxlen = sizeof(unsigned long),
.mode = 0644,
- .proc_handler = mmap_min_addr_handler,
+ .proc_handler = proc_doulongvec_minmax,
+ .callback = mmap_min_addr_handler,
},
#endif
#ifdef CONFIG_NUMA
diff --git a/security/min_addr.c b/security/min_addr.c
index f728728..3e5a41c 100644
--- a/security/min_addr.c
+++ b/security/min_addr.c
@@ -28,19 +28,14 @@ static void update_mmap_min_addr(void)
* sysctl handler which just sets dac_mmap_min_addr = the new value and then
* calls update_mmap_min_addr() so non MAP_FIXED hints get rounded properly
*/
-int mmap_min_addr_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos)
+int mmap_min_addr_handler(void)
{
- int ret;
-
- if (write && !capable(CAP_SYS_RAWIO))
+ if (!capable(CAP_SYS_RAWIO))
return -EPERM;

- ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
-
update_mmap_min_addr();

- return ret;
+ return 0;
}

static int __init init_mmap_min_addr(void)
--
1.7.8.5

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