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authorAlan Cox <alan@redhat.com>2008-10-29 14:01:20 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-26 14:27:09 -0700
commit3f955fe683ffdda7fd68e0b61779001cb9b50011 (patch)
treeb226e5056dcd6defc352ffc5ec29b3dd7c091c49 /include
parent0ce0dd4ec9890eefb7b656c74bc5256c60626a85 (diff)
nfsd: fix vm overcommit crash
commit 731572d39fcd3498702eda4600db4c43d51e0b26 upstream. Junjiro R. Okajima reported a problem where knfsd crashes if you are using it to export shmemfs objects and run strict overcommit. In this situation the current->mm based modifier to the overcommit goes through a NULL pointer. We could simply check for NULL and skip the modifier but we've caught other real bugs in the past from mm being NULL here - cases where we did need a valid mm set up (eg the exec bug about a year ago). To preserve the checks and get the logic we want shuffle the checking around and add a new helper to the vm_ security wrappers Also fix a current->mm reference in nommu that should use the passed mm [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix build] Reported-by: Junjiro R. Okajima <hooanon05@yahoo.co.jp> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
-rw-r--r--include/linux/security.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/security.h b/include/linux/security.h
index 1638afdbe4e3..afb426a5b5d0 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1590,6 +1590,7 @@ 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_vm_enough_memory_kern(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);
@@ -1825,6 +1826,11 @@ static inline int security_vm_enough_memory(long pages)
return cap_vm_enough_memory(current->mm, pages);
}
+static inline int security_vm_enough_memory_kern(long pages)
+{
+ return cap_vm_enough_memory(current->mm, pages);
+}
+
static inline int security_vm_enough_memory_mm(struct mm_struct *mm, long pages)
{
return cap_vm_enough_memory(mm, pages);