From: Shawn C <[email protected]> Hi kernel maintainers,
It won't allow the address above the TASK_SIZE being mmap'ed( or mprotect'ed). This patch is from PaX/Grsecurity. Thanks for your review time! Signed-off-by: Shawn C <[email protected]> --- mm/madvise.c | 4 ++++ mm/mempolicy.c | 5 +++++ mm/mlock.c | 4 ++++ mm/mprotect.c | 5 +++++ 4 files changed, 18 insertions(+) diff --git a/mm/madvise.c b/mm/madvise.c index d551475..3f5dd3d 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -484,6 +484,10 @@ SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior) if (end < start) return error; + /* We should never reach the kernel address space here */ + if (end > TASK_SIZE) + return error; + error = 0; if (end == start) return error; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ede2629..56c2eed 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1161,6 +1161,11 @@ static long do_mbind(unsigned long start, unsigned long len, if (end < start) return -EINVAL; + + /* We should never reach the kernel address space here */ + if (end > TASK_SIZE) + return -EINVAL; + if (end == start) return 0; diff --git a/mm/mlock.c b/mm/mlock.c index 6fd2cf1..c7f6785 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -566,6 +566,10 @@ static int do_mlock(unsigned long start, size_t len, int on) return -EINVAL; if (end == start) return 0; + + if (end > TASK_SIZE) + return -EINVAL; + vma = find_vma(current->mm, start); if (!vma || vma->vm_start > start) return -ENOMEM; diff --git a/mm/mprotect.c b/mm/mprotect.c index 8858483..cd58a31 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -351,6 +351,11 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, end = start + len; if (end <= start) return -ENOMEM; + + /* We should never reach the kernel address space here */ + if (end > TASK_SIZE) + return -EINVAL; + if (!arch_validate_prot(prot)) return -EINVAL; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
