From 6d7825b10dbeafd60627cd04291fb10ec2b5b973 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 13 Mar 2013 14:59:43 -0700 Subject: mm/fremap.c: fix oops on error path If find_vma() fails, sys_remap_file_pages() will dereference `vma', which contains NULL. Fix it by checking the pointer. (We could alternatively check for err==0, but this seems more direct) (The vm_flags change is to squish a bogus used-uninitialised warning without adding extra code). Reported-by: Tommi Rantala Cc: Michel Lespinasse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/fremap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/fremap.c b/mm/fremap.c index 0cd4c11488e..6a8da7ee85f 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -163,7 +163,8 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, * and that the remapped range is valid and fully within * the single existing vma. */ - if (!vma || !(vma->vm_flags & VM_SHARED)) + vm_flags = vma->vm_flags; + if (!vma || !(vm_flags & VM_SHARED)) goto out; if (!vma->vm_ops || !vma->vm_ops->remap_pages) @@ -254,7 +255,8 @@ get_write_lock: */ out: - vm_flags = vma->vm_flags; + if (vma) + vm_flags = vma->vm_flags; if (likely(!has_write_lock)) up_read(&mm->mmap_sem); else -- cgit v1.2.3-70-g09d2