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| author | Alan Cox <alan@redhat.com> | 2008-10-29 14:01:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-30 11:38:47 -0700 |
| commit | 731572d39fcd3498702eda4600db4c43d51e0b26 (patch) | |
| tree | f892907ae20539845f353d72d2a2bf202b67e007 /include/linux | |
| parent | 6c89161b10f5771ee0b51ada0fce0e8835e72ade (diff) | |
| download | linux-731572d39fcd3498702eda4600db4c43d51e0b26.tar.gz linux-731572d39fcd3498702eda4600db4c43d51e0b26.tar.bz2 linux-731572d39fcd3498702eda4600db4c43d51e0b26.zip | |
nfsd: fix vm overcommit crash
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>
Diffstat (limited to 'include/linux')
| -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 f5c4a51eb42e..c13f1cec9abb 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1585,6 +1585,7 @@ 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); @@ -1820,6 +1821,11 @@ 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); |