Re: [BUGFIX] NULL pointer dereference in __vm_enough_memory()
From: Alan Cox
Date: Sun Aug 12 2007 - 11:17:48 EST
Try this (it compiles but isnt tested). Its a weekend here, the sun is
shining, the beach is a short walk, and I have more interesting things to
do right now 8)
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/include/linux/mm.h linux-2.6.23rc1-mm1/include/linux/mm.h
--- linux.vanilla-2.6.23rc1-mm1/include/linux/mm.h 2007-07-26 15:02:58.000000000 +0100
+++ linux-2.6.23rc1-mm1/include/linux/mm.h 2007-08-12 13:54:24.614647536 +0100
@@ -1079,7 +1079,7 @@
}
/* mmap.c */
-extern int __vm_enough_memory(long pages, int cap_sys_admin);
+extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
extern void vma_adjust(struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert);
extern struct vm_area_struct *vma_merge(struct mm_struct *,
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/include/linux/security.h linux-2.6.23rc1-mm1/include/linux/security.h
--- linux.vanilla-2.6.23rc1-mm1/include/linux/security.h 2007-07-26 15:02:58.000000000 +0100
+++ linux-2.6.23rc1-mm1/include/linux/security.h 2007-08-12 14:13:10.383504656 +0100
@@ -58,7 +58,7 @@
extern int cap_task_setioprio (struct task_struct *p, int ioprio);
extern int cap_task_setnice (struct task_struct *p, int nice);
extern int cap_syslog (int type);
-extern int cap_vm_enough_memory (long pages);
+extern int cap_vm_enough_memory (struct mm_struct *mm, long pages);
struct msghdr;
struct sk_buff;
@@ -1129,6 +1129,7 @@
* Return 0 if permission is granted.
* @vm_enough_memory:
* Check permissions for allocating a new virtual mapping.
+ * @mm contains the mm struct it is being added to.
* @pages contains the number of pages.
* Return 0 if permission is granted.
*
@@ -1173,7 +1174,7 @@
int (*quota_on) (struct dentry * dentry);
int (*syslog) (int type);
int (*settime) (struct timespec *ts, struct timezone *tz);
- int (*vm_enough_memory) (long pages);
+ int (*vm_enough_memory) (struct mm_struct *mm, long pages);
int (*bprm_alloc_security) (struct linux_binprm * bprm);
void (*bprm_free_security) (struct linux_binprm * bprm);
@@ -1439,6 +1440,7 @@
int security_syslog(int type);
int security_settime(struct timespec *ts, struct timezone *tz);
int security_vm_enough_memory(long pages);
+int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
int security_bprm_alloc(struct linux_binprm *bprm);
void security_bprm_free(struct linux_binprm *bprm);
void security_bprm_apply_creds(struct linux_binprm *bprm, int unsafe);
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/mm/mmap.c linux-2.6.23rc1-mm1/mm/mmap.c
--- linux.vanilla-2.6.23rc1-mm1/mm/mmap.c 2007-07-26 15:02:58.000000000 +0100
+++ linux-2.6.23rc1-mm1/mm/mmap.c 2007-08-12 13:53:22.000000000 +0100
@@ -93,7 +93,7 @@
* Note this is a helper function intended to be used by LSMs which
* wish to use this logic.
*/
-int __vm_enough_memory(long pages, int cap_sys_admin)
+int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
{
unsigned long free, allowed;
@@ -166,7 +166,7 @@
/* Don't let a single process grow too big:
leave 3% of the size of this process for other processes */
- allowed -= current->mm->total_vm / 32;
+ allowed -= mm->total_vm / 32;
/*
* cast `allowed' as a signed long because vm_committed_space
@@ -2058,7 +2058,7 @@
if (__vma && __vma->vm_start < vma->vm_end)
return -ENOMEM;
if ((vma->vm_flags & VM_ACCOUNT) &&
- security_vm_enough_memory(vma_pages(vma)))
+ security_vm_enough_memory_mm(mm, vma_pages(vma)))
return -ENOMEM;
vma_link(mm, vma, prev, rb_link, rb_parent);
return 0;
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/mm/nommu.c linux-2.6.23rc1-mm1/mm/nommu.c
--- linux.vanilla-2.6.23rc1-mm1/mm/nommu.c 2007-07-26 15:02:08.000000000 +0100
+++ linux-2.6.23rc1-mm1/mm/nommu.c 2007-08-12 13:53:57.000000000 +0100
@@ -1270,7 +1270,7 @@
* Note this is a helper function intended to be used by LSMs which
* wish to use this logic.
*/
-int __vm_enough_memory(long pages, int cap_sys_admin)
+int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
{
unsigned long free, allowed;
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/security/commoncap.c linux-2.6.23rc1-mm1/security/commoncap.c
--- linux.vanilla-2.6.23rc1-mm1/security/commoncap.c 2007-07-26 15:02:59.000000000 +0100
+++ linux-2.6.23rc1-mm1/security/commoncap.c 2007-08-12 14:13:29.000000000 +0100
@@ -489,13 +489,13 @@
return 0;
}
-int cap_vm_enough_memory(long pages)
+int cap_vm_enough_memory(struct mm_struct *mm, long pages)
{
int cap_sys_admin = 0;
if (cap_capable(current, CAP_SYS_ADMIN) == 0)
cap_sys_admin = 1;
- return __vm_enough_memory(pages, cap_sys_admin);
+ return __vm_enough_memory(mm, pages, cap_sys_admin);
}
EXPORT_SYMBOL(cap_capable);
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/security/dummy.c linux-2.6.23rc1-mm1/security/dummy.c
--- linux.vanilla-2.6.23rc1-mm1/security/dummy.c 2007-07-26 15:02:59.000000000 +0100
+++ linux-2.6.23rc1-mm1/security/dummy.c 2007-08-12 14:10:49.000000000 +0100
@@ -107,13 +107,13 @@
return 0;
}
-static int dummy_vm_enough_memory(long pages)
+static int dummy_vm_enough_memory(struct mm_struct *mm, long pages)
{
int cap_sys_admin = 0;
if (dummy_capable(current, CAP_SYS_ADMIN) == 0)
cap_sys_admin = 1;
- return __vm_enough_memory(pages, cap_sys_admin);
+ return __vm_enough_memory(mm, pages, cap_sys_admin);
}
static int dummy_bprm_alloc_security (struct linux_binprm *bprm)
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/security/security.c linux-2.6.23rc1-mm1/security/security.c
--- linux.vanilla-2.6.23rc1-mm1/security/security.c 2007-07-26 15:02:59.000000000 +0100
+++ linux-2.6.23rc1-mm1/security/security.c 2007-08-12 13:47:53.000000000 +0100
@@ -237,10 +237,14 @@
return security_ops->settime(ts, tz);
}
-
int security_vm_enough_memory(long pages)
{
- return security_ops->vm_enough_memory(pages);
+ return security_ops->vm_enough_memory(current->mm, pages);
+}
+
+int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
+{
+ return security_ops->vm_enough_memory(mm, pages);
}
int security_bprm_alloc(struct linux_binprm *bprm)
diff -u --new-file --recursive --exclude-from /usr/src/exclude linux.vanilla-2.6.23rc1-mm1/security/selinux/hooks.c linux-2.6.23rc1-mm1/security/selinux/hooks.c
--- linux.vanilla-2.6.23rc1-mm1/security/selinux/hooks.c 2007-07-26 15:02:59.000000000 +0100
+++ linux-2.6.23rc1-mm1/security/selinux/hooks.c 2007-08-12 14:11:21.000000000 +0100
@@ -1584,7 +1584,7 @@
* Do not audit the selinux permission check, as this is applied to all
* processes that allocate mappings.
*/
-static int selinux_vm_enough_memory(long pages)
+static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
{
int rc, cap_sys_admin = 0;
struct task_security_struct *tsec = current->security;
@@ -1600,7 +1600,7 @@
if (rc == 0)
cap_sys_admin = 1;
- return __vm_enough_memory(pages, cap_sys_admin);
+ return __vm_enough_memory(mm, pages, cap_sys_admin);
}
/* binprm security operations */
-
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