From 2fd4ef85e0db9ed75c98e13953257a967ea55e03 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Wed, 14 Sep 2005 06:13:02 +0100 Subject: [PATCH] error path in setup_arg_pages() misses vm_unacct_memory() Pavel Emelianov and Kirill Korotaev observe that fs and arch users of security_vm_enough_memory tend to forget to vm_unacct_memory when a failure occurs further down (typically in setup_arg_pages variants). These are all users of insert_vm_struct, and that reservation will only be unaccounted on exit if the vma is marked VM_ACCOUNT: which in some cases it is (hidden inside VM_STACK_FLAGS) and in some cases it isn't. So x86_64 32-bit and ppc64 vDSO ELFs have been leaking memory into Committed_AS each time they're run. But don't add VM_ACCOUNT to them, it's inappropriate to reserve against the very unlikely case that gdb be used to COW a vDSO page - we ought to do something about that in do_wp_page, but there are yet other inconsistencies to be resolved. The safe and economical way to fix this is to let insert_vm_struct do the security_vm_enough_memory check when it finds VM_ACCOUNT is set. And the MIPS irix_brk has been calling security_vm_enough_memory before calling do_brk which repeats it, doubly accounting and so also leaking. Remove that, and all the fs and arch calls to security_vm_enough_memory: give it a less misleading name later on. Signed-off-by: Hugh Dickins Signed-Off-By: Kirill Korotaev Signed-off-by: Linus Torvalds --- arch/mips/kernel/sysirix.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/sysirix.c b/arch/mips/kernel/sysirix.c index 4de155699c4f..7ae4af476974 100644 --- a/arch/mips/kernel/sysirix.c +++ b/arch/mips/kernel/sysirix.c @@ -581,18 +581,13 @@ asmlinkage int irix_brk(unsigned long brk) } /* - * Check if we have enough memory.. + * Ok, looks good - let it rip. */ - if (security_vm_enough_memory((newbrk-oldbrk) >> PAGE_SHIFT)) { + if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk) { ret = -ENOMEM; goto out; } - - /* - * Ok, looks good - let it rip. - */ mm->brk = brk; - do_brk(oldbrk, newbrk-oldbrk); ret = 0; out: -- cgit v1.2.2