From: Chris Wright <chrisw@osdl.org>
Date: Sun, 1 May 2005 15:58:38 +0000 (-0700)
Subject: [PATCH] RLIMIT_MEMLOCK checking fix
X-Git-Tag: v2.6.12-rc4~136^2~176
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=93ea1d0a12623dc1a693642b5758261f35f9bf96;p=linux-2.6

[PATCH] RLIMIT_MEMLOCK checking fix

Always use page counts when doing RLIMIT_MEMLOCK checking to avoid possible
overflow.

Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index 1ec0f6e9c0..01f9793591 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -937,9 +937,10 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
 	/* mlock MCL_FUTURE? */
 	if (vm_flags & VM_LOCKED) {
 		unsigned long locked, lock_limit;
-		locked = mm->locked_vm << PAGE_SHIFT;
+		locked = len >> PAGE_SHIFT;
+		locked += mm->locked_vm;
 		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
-		locked += len;
+		lock_limit >>= PAGE_SHIFT;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
 			return -EAGAIN;
 	}
@@ -1822,9 +1823,10 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
 	 */
 	if (mm->def_flags & VM_LOCKED) {
 		unsigned long locked, lock_limit;
-		locked = mm->locked_vm << PAGE_SHIFT;
+		locked = len >> PAGE_SHIFT;
+		locked += mm->locked_vm;
 		lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
-		locked += len;
+		lock_limit >>= PAGE_SHIFT;
 		if (locked > lock_limit && !capable(CAP_IPC_LOCK))
 			return -EAGAIN;
 	}