diff options
| author | Alan Cox <alan@redhat.com> | 2008-10-29 14:01:20 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-26 14:27:09 -0700 |
| commit | 3f955fe683ffdda7fd68e0b61779001cb9b50011 (patch) | |
| tree | b226e5056dcd6defc352ffc5ec29b3dd7c091c49 /include | |
| parent | 0ce0dd4ec9890eefb7b656c74bc5256c60626a85 (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.h | 6 |
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); |