summaryrefslogtreecommitdiff
path: root/drivers/misc/lkdtm/heap.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-05 13:42:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-05 13:42:16 -0700
commiteed0218e8cae9fcd186c30e9fcf5fe46a87e056e (patch)
tree799a1360b947a56d05a60433fdf60a96bf3b3348 /drivers/misc/lkdtm/heap.c
parent3f8b8e7dbd79086ad48fcff33de9399f3da66a69 (diff)
parent6f746d485fb9188dc67dce7de63d21f0c28a1f2e (diff)
downloadlwn-eed0218e8cae9fcd186c30e9fcf5fe46a87e056e.tar.gz
lwn-eed0218e8cae9fcd186c30e9fcf5fe46a87e056e.zip
Merge tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc driver updates from Greg KH: "Here is the big set of char / misc and other driver subsystem updates for 5.14-rc1. Included in here are: - habanalabs driver updates - fsl-mc driver updates - comedi driver updates - fpga driver updates - extcon driver updates - interconnect driver updates - mei driver updates - nvmem driver updates - phy driver updates - pnp driver updates - soundwire driver updates - lots of other tiny driver updates for char and misc drivers This is looking more and more like the "various driver subsystems mushed together" tree... All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (292 commits) mcb: Use DEFINE_RES_MEM() helper macro and fix the end address PNP: moved EXPORT_SYMBOL so that it immediately followed its function/variable bus: mhi: pci-generic: Add missing 'pci_disable_pcie_error_reporting()' calls bus: mhi: Wait for M2 state during system resume bus: mhi: core: Fix power down latency intel_th: Wait until port is in reset before programming it intel_th: msu: Make contiguous buffers uncached intel_th: Remove an unused exit point from intel_th_remove() stm class: Spelling fix nitro_enclaves: Set Bus Master for the NE PCI device misc: ibmasm: Modify matricies to matrices misc: vmw_vmci: return the correct errno code siox: Simplify error handling via dev_err_probe() fpga: machxo2-spi: Address warning about unused variable lkdtm/heap: Add init_on_alloc tests selftests/lkdtm: Enable various testable CONFIGs lkdtm: Add CONFIG hints in errors where possible lkdtm: Enable DOUBLE_FAULT on all architectures lkdtm/heap: Add vmalloc linear overflow test lkdtm/bugs: XFAIL UNALIGNED_LOAD_STORE_WRITE ...
Diffstat (limited to 'drivers/misc/lkdtm/heap.c')
-rw-r--r--drivers/misc/lkdtm/heap.c97
1 files changed, 92 insertions, 5 deletions
diff --git a/drivers/misc/lkdtm/heap.c b/drivers/misc/lkdtm/heap.c
index 1323bc16f113..3d9aae5821a0 100644
--- a/drivers/misc/lkdtm/heap.c
+++ b/drivers/misc/lkdtm/heap.c
@@ -5,6 +5,7 @@
*/
#include "lkdtm.h"
#include <linux/slab.h>
+#include <linux/vmalloc.h>
#include <linux/sched.h>
static struct kmem_cache *double_free_cache;
@@ -12,17 +13,36 @@ static struct kmem_cache *a_cache;
static struct kmem_cache *b_cache;
/*
+ * If there aren't guard pages, it's likely that a consecutive allocation will
+ * let us overflow into the second allocation without overwriting something real.
+ */
+void lkdtm_VMALLOC_LINEAR_OVERFLOW(void)
+{
+ char *one, *two;
+
+ one = vzalloc(PAGE_SIZE);
+ two = vzalloc(PAGE_SIZE);
+
+ pr_info("Attempting vmalloc linear overflow ...\n");
+ memset(one, 0xAA, PAGE_SIZE + 1);
+
+ vfree(two);
+ vfree(one);
+}
+
+/*
* This tries to stay within the next largest power-of-2 kmalloc cache
* to avoid actually overwriting anything important if it's not detected
* correctly.
*/
-void lkdtm_OVERWRITE_ALLOCATION(void)
+void lkdtm_SLAB_LINEAR_OVERFLOW(void)
{
size_t len = 1020;
u32 *data = kmalloc(len, GFP_KERNEL);
if (!data)
return;
+ pr_info("Attempting slab linear overflow ...\n");
data[1024 / sizeof(u32)] = 0x12345678;
kfree(data);
}
@@ -89,9 +109,10 @@ void lkdtm_READ_AFTER_FREE(void)
if (saw != *val) {
/* Good! Poisoning happened, so declare a win. */
pr_info("Memory correctly poisoned (%x)\n", saw);
- BUG();
+ } else {
+ pr_err("FAIL: Memory was not poisoned!\n");
+ pr_expected_config_param(CONFIG_INIT_ON_FREE_DEFAULT_ON, "init_on_free");
}
- pr_info("Memory was not poisoned\n");
kfree(val);
}
@@ -145,13 +166,79 @@ void lkdtm_READ_BUDDY_AFTER_FREE(void)
if (saw != *val) {
/* Good! Poisoning happened, so declare a win. */
pr_info("Memory correctly poisoned (%x)\n", saw);
- BUG();
+ } else {
+ pr_err("FAIL: Buddy page was not poisoned!\n");
+ pr_expected_config_param(CONFIG_INIT_ON_FREE_DEFAULT_ON, "init_on_free");
+ }
+
+ kfree(val);
+}
+
+void lkdtm_SLAB_INIT_ON_ALLOC(void)
+{
+ u8 *first;
+ u8 *val;
+
+ first = kmalloc(512, GFP_KERNEL);
+ if (!first) {
+ pr_info("Unable to allocate 512 bytes the first time.\n");
+ return;
+ }
+
+ memset(first, 0xAB, 512);
+ kfree(first);
+
+ val = kmalloc(512, GFP_KERNEL);
+ if (!val) {
+ pr_info("Unable to allocate 512 bytes the second time.\n");
+ return;
+ }
+ if (val != first) {
+ pr_warn("Reallocation missed clobbered memory.\n");
}
- pr_info("Buddy page was not poisoned\n");
+ if (memchr(val, 0xAB, 512) == NULL) {
+ pr_info("Memory appears initialized (%x, no earlier values)\n", *val);
+ } else {
+ pr_err("FAIL: Slab was not initialized\n");
+ pr_expected_config_param(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, "init_on_alloc");
+ }
kfree(val);
}
+void lkdtm_BUDDY_INIT_ON_ALLOC(void)
+{
+ u8 *first;
+ u8 *val;
+
+ first = (u8 *)__get_free_page(GFP_KERNEL);
+ if (!first) {
+ pr_info("Unable to allocate first free page\n");
+ return;
+ }
+
+ memset(first, 0xAB, PAGE_SIZE);
+ free_page((unsigned long)first);
+
+ val = (u8 *)__get_free_page(GFP_KERNEL);
+ if (!val) {
+ pr_info("Unable to allocate second free page\n");
+ return;
+ }
+
+ if (val != first) {
+ pr_warn("Reallocation missed clobbered memory.\n");
+ }
+
+ if (memchr(val, 0xAB, PAGE_SIZE) == NULL) {
+ pr_info("Memory appears initialized (%x, no earlier values)\n", *val);
+ } else {
+ pr_err("FAIL: Slab was not initialized\n");
+ pr_expected_config_param(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, "init_on_alloc");
+ }
+ free_page((unsigned long)val);
+}
+
void lkdtm_SLAB_FREE_DOUBLE(void)
{
int *val;