From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org, linux-kernel@vger.kernel.org
Cc: linux-arch@vger.kernel.org, Borislav Petkov <bp@alien8.de>,
Nadav Amit <nadav.amit@gmail.com>,
Kees Cook <keescook@chromium.org>,
Brian Gerst <brgerst@gmail.com>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@redhat.com>, Jann Horn <jann@thejh.net>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Andy Lutomirski <luto@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH v5 08/32] dma-api: Teach the "DMA-from-stack" check about vmapped stacks
Date: Mon, 11 Jul 2016 13:53:41 -0700 [thread overview]
Message-ID: <4a1d5fa16a28b32509ece3611690be48a8746778.1468270393.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1468270393.git.luto@kernel.org>
In-Reply-To: <cover.1468270393.git.luto@kernel.org>
If we're using CONFIG_VMAP_STACK and we manage to point an sg entry
at the stack, then either the sg page will be in highmem or sg_virt
will return the direct-map alias. In neither case will the existing
check_for_stack() implementation realize that it's a stack page.
Fix it by explicitly checking for stack pages.
This has no effect by itself. It's broken out for ease of review.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
lib/dma-debug.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 51a76af25c66..5b2e63cba90e 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -22,6 +22,7 @@
#include <linux/stacktrace.h>
#include <linux/dma-debug.h>
#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/export.h>
@@ -1162,11 +1163,35 @@ static void check_unmap(struct dma_debug_entry *ref)
put_hash_bucket(bucket, &flags);
}
-static void check_for_stack(struct device *dev, void *addr)
+static void check_for_stack(struct device *dev,
+ struct page *page, size_t offset)
{
- if (object_is_on_stack(addr))
- err_printk(dev, NULL, "DMA-API: device driver maps memory from "
- "stack [addr=%p]\n", addr);
+ void *addr;
+ struct vm_struct *stack_vm_area = task_stack_vm_area(current);
+
+ if (!stack_vm_area) {
+ /* Stack is direct-mapped. */
+ if (PageHighMem(page))
+ return;
+ addr = page_address(page) + offset;
+ if (object_is_on_stack(addr))
+ err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [addr=%p]\n",
+ addr);
+ } else {
+ /* Stack is vmalloced. */
+ int i;
+
+ for (i = 0; i < stack_vm_area->nr_pages; i++) {
+ if (page != stack_vm_area->pages[i])
+ continue;
+
+ addr = (u8 *)current->stack + i * PAGE_SIZE +
+ offset;
+ err_printk(dev, NULL, "DMA-API: device driver maps memory from stack [probable addr=%p]\n",
+ addr);
+ break;
+ }
+ }
}
static inline bool overlap(void *addr, unsigned long len, void *start, void *end)
@@ -1289,10 +1314,11 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
if (map_single)
entry->type = dma_debug_single;
+ check_for_stack(dev, page, offset);
+
if (!PageHighMem(page)) {
void *addr = page_address(page) + offset;
- check_for_stack(dev, addr);
check_for_illegal_area(dev, addr, size);
}
@@ -1384,8 +1410,9 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
entry->sg_call_ents = nents;
entry->sg_mapped_ents = mapped_ents;
+ check_for_stack(dev, sg_page(s), s->offset);
+
if (!PageHighMem(sg_page(s))) {
- check_for_stack(dev, sg_virt(s));
check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s));
}
--
2.7.4
next prev parent reply other threads:[~2016-07-11 20:54 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-11 20:53 [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 01/32] bluetooth: Switch SMP to crypto_cipher_encrypt_one() Andy Lutomirski
2016-07-14 19:10 ` Andy Lutomirski
2016-07-14 20:30 ` Marcel Holtmann
2016-07-14 20:41 ` David Miller
2016-07-11 20:53 ` [PATCH v5 02/32] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 03/32] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski
2016-07-22 4:43 ` [kernel-hardening] " Valdis.Kletnieks
2016-07-22 5:34 ` Andy Lutomirski
2016-07-22 10:21 ` Ingo Molnar
2016-07-22 18:21 ` Andy Lutomirski
2016-07-22 18:31 ` Andy Lutomirski
2016-07-22 20:11 ` Ingo Molnar
2016-07-23 5:21 ` Valdis.Kletnieks
2016-07-23 14:58 ` Nicolai Stange
2016-07-28 9:26 ` Valdis.Kletnieks
2016-07-11 20:53 ` [PATCH v5 04/32] x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 05/32] mm: Track NR_KERNEL_STACK in KiB instead of number of stacks Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 06/32] mm: Fix memcg stack accounting for sub-page stacks Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 07/32] fork: Add generic vmalloced stack support Andy Lutomirski
2016-07-11 20:53 ` Andy Lutomirski [this message]
2016-07-11 20:53 ` [PATCH v5 09/32] x86/dumpstack: When OOPSing, rewind the stack before do_exit() Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 10/32] x86/dumpstack: Honor supplied @regs arg Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 11/32] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 12/32] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 13/32] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm Andy Lutomirski
2016-07-12 17:51 ` [kernel-hardening] " Dave Hansen
2016-07-12 18:03 ` Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 14/32] x86/mm/64: Enable vmapped stacks Andy Lutomirski
2016-07-13 7:53 ` Ingo Molnar
2016-07-13 18:42 ` Andy Lutomirski
2016-07-14 8:34 ` Ingo Molnar
2016-07-14 16:51 ` Andy Lutomirski
2016-07-14 18:45 ` Ingo Molnar
2016-07-11 20:53 ` [PATCH v5 15/32] x86/mm: Improve stack-overflow #PF handling Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 16/32] x86: Move uaccess_err and sig_on_uaccess_err to thread_struct Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 17/32] x86: Move addr_limit " Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 18/32] signal: Consolidate {TS,TLF}_RESTORE_SIGMASK code Andy Lutomirski
2016-07-12 11:57 ` Brian Gerst
2016-07-12 23:01 ` Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 19/32] x86/smp: Remove stack_smp_processor_id() Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 20/32] x86/smp: Remove unnecessary initialization of thread_info::cpu Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 21/32] x86/asm: Move 'status' from struct thread_info to struct thread_struct Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 22/32] kdb: Use task_cpu() instead of task_thread_info()->cpu Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 23/32] printk: When dumping regs, show the stack, not thread_info Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 24/32] x86/entry: Get rid of pt_regs_to_thread_info() Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 25/32] um: Stop conflating task_struct::stack with thread_info Andy Lutomirski
2016-07-11 20:53 ` [PATCH v5 26/32] sched: Allow putting thread_info into task_struct Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 27/32] x86: Move " Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 28/32] sched: Add try_get_task_stack() and put_task_stack() Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 29/32] kthread: to_live_kthread() needs try_get_task_stack() Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 30/32] x86/dumpstack: Pin the target stack in save_stack_trace_tsk() Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 31/32] sched: Free the stack early if CONFIG_THREAD_INFO_IN_TASK Andy Lutomirski
2016-07-11 20:54 ` [PATCH v5 32/32] fork: Cache two thread stacks per cpu if CONFIG_VMAP_STACK is set Andy Lutomirski
2016-07-12 8:56 ` [PATCH v5 00/32] virtually mapped stacks and thread_info cleanup Herbert Xu
2016-07-13 8:54 ` Christian Borntraeger
2016-07-13 18:36 ` Andy Lutomirski
2016-07-13 18:53 ` Christian Borntraeger
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