Insert KMSAN hooks that check for potential memory errors and/or make
necessary bookkeeping changes:
- allocate/split/deallocate metadata pages in
alloc_pages()/split_page()/free_page();
- clear page shadow and origins in clear_page(), copy_user_highpage();
- copy page metadata in copy_highpage(), wp_page_copy();
- handle vmap()/vunmap()/iounmap();
- handle task creation and deletion;
- initialize result of vscnprintf() in vprintk_store();
- call softirq entry/exit hooks in kernel/softirq.c;
- check/initialize memory sent to/read from USB, I2C, and network
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
To: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
---
v2:
- dropped call to kmsan_handle_vprintk, updated comment in printk.c
v3:
- put KMSAN_INIT_VALUE on a separate line in vprintk_store()
- dropped call to kmsan_handle_i2c_transfer()
Change-Id: I1250a928d9263bf71fdaa067a070bdee686ef47b
---
arch/x86/include/asm/page_64.h | 13 +++++++++++++
arch/x86/mm/ioremap.c | 3 +++
drivers/usb/core/urb.c | 2 ++
include/linux/highmem.h | 4 ++++
kernel/exit.c | 2 ++
kernel/fork.c | 2 ++
kernel/kthread.c | 2 ++
kernel/printk/printk.c | 6 ++++++
kernel/softirq.c | 5 +++++
lib/ioremap.c | 5 +++++
mm/compaction.c | 9 +++++++++
mm/gup.c | 3 +++
mm/memory.c | 2 ++
mm/page_alloc.c | 16 ++++++++++++++++
mm/vmalloc.c | 23 +++++++++++++++++++++--
net/sched/sch_generic.c | 2 ++
16 files changed, 97 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 939b1cff4a7b..0ba43d93414f 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -44,14 +44,27 @@ void clear_page_orig(void *page);
void clear_page_rep(void *page);
void clear_page_erms(void *page);
+/* This is an assembly header, avoid including too much of kmsan.h */
+#ifdef CONFIG_KMSAN
+void kmsan_clear_page(void *page_addr);
+#endif
+__no_sanitize_memory
static inline void clear_page(void *page)
{
+#ifdef CONFIG_KMSAN
+ /* alternative_call_2() changes |page|. */
+ void *page_copy = page;
+#endif
alternative_call_2(clear_page_orig,
clear_page_rep, X86_FEATURE_REP_GOOD,
clear_page_erms, X86_FEATURE_ERMS,
"=D" (page),
"0" (page)
: "cc", "memory", "rax", "rcx");
+#ifdef CONFIG_KMSAN
+ /* Clear KMSAN shadow for the pages that have it. */
+ kmsan_clear_page(page_copy);
+#endif
}
void copy_page(void *to, void *from);
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index a39dcdb5ae34..fdb2abc11a82 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -7,6 +7,7 @@
* (C) Copyright 1995 1996 Linus Torvalds
*/
+#include <linux/kmsan.h>
#include <linux/memblock.h>
#include <linux/init.h>
#include <linux/io.h>
@@ -451,6 +452,8 @@ void iounmap(volatile void __iomem *addr)
return;
}
+ kmsan_iounmap_page_range((unsigned long)addr,
+ (unsigned long)addr + get_vm_area_size(p));
free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
/* Finally remove it */
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 0eab79f82ce4..5bdb54d71c2e 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -8,6 +8,7 @@
#include <linux/bitops.h>
#include <linux/slab.h>
#include <linux/log2.h>
+#include <linux/kmsan-checks.h>
#include <linux/usb.h>
#include <linux/wait.h>
#include <linux/usb/hcd.h>
@@ -401,6 +402,7 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL |
URB_DMA_SG_COMBINED);
urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN);
+ kmsan_handle_urb(urb, is_out);
if (xfertype != USB_ENDPOINT_XFER_CONTROL &&
dev->state < USB_STATE_CONFIGURED)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ea5cdbd8c2c3..623b56f48685 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -5,6 +5,7 @@
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/bug.h>
+#include <linux/kmsan.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
@@ -255,6 +256,8 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
vfrom = kmap_atomic(from);
vto = kmap_atomic(to);
copy_user_page(vto, vfrom, vaddr, to);
+ /* User pages don't have shadow, just clear the destination. */
+ kmsan_clear_page(page_address(to));
kunmap_atomic(vto);
kunmap_atomic(vfrom);
}
@@ -270,6 +273,7 @@ static inline void copy_highpage(struct page *to, struct page *from)
vfrom = kmap_atomic(from);
vto = kmap_atomic(to);
copy_page(vto, vfrom);
+ kmsan_copy_page_meta(to, from);
kunmap_atomic(vto);
kunmap_atomic(vfrom);
}
diff --git a/kernel/exit.c b/kernel/exit.c
index a46a50d67002..9e3ce929110b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -60,6 +60,7 @@
#include <linux/writeback.h>
#include <linux/shm.h>
#include <linux/kcov.h>
+#include <linux/kmsan.h>
#include <linux/random.h>
#include <linux/rcuwait.h>
#include <linux/compat.h>
@@ -719,6 +720,7 @@ void __noreturn do_exit(long code)
profile_task_exit(tsk);
kcov_task_exit(tsk);
+ kmsan_task_exit(tsk);
WARN_ON(blk_needs_flush_plug(tsk));
diff --git a/kernel/fork.c b/kernel/fork.c
index bcdf53125210..0f08952a42dc 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -37,6 +37,7 @@
#include <linux/fdtable.h>
#include <linux/iocontext.h>
#include <linux/key.h>
+#include <linux/kmsan.h>
#include <linux/binfmts.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
@@ -931,6 +932,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
+ kmsan_task_create(tsk);
#ifdef CONFIG_FAULT_INJECTION
tsk->fail_nth = 0;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index b262f47046ca..33ca743ca8b5 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -17,6 +17,7 @@
#include <linux/unistd.h>
#include <linux/file.h>
#include <linux/export.h>
+#include <linux/kmsan.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/freezer.h>
@@ -350,6 +351,7 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data),
set_cpus_allowed_ptr(task, cpu_all_mask);
}
kfree(create);
+ kmsan_task_create(task);
return task;
}
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index ca65327a6de8..c9ef7fb0906f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1915,6 +1915,12 @@ int vprintk_store(int facility, int level,
* prefix which might be passed-in as a parameter.
*/
text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+ /*
+ * If any of vscnprintf() arguments is uninitialized, KMSAN will report
+ * one or more errors and also probably mark text_len as uninitialized.
+ * Initialize |text_len| to prevent the errors from spreading further.
+ */
+ text_len = KMSAN_INIT_VALUE(text_len);
/* mark and strip a trailing newline */
if (text_len && text[text_len-1] == '\n') {
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 0427a86743a4..6d566dd68b35 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -11,6 +11,7 @@
#include <linux/export.h>
#include <linux/kernel_stat.h>
+#include <linux/kmsan.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/mm.h>
@@ -370,7 +371,9 @@ static inline void invoke_softirq(void)
* it is the irq stack, because it should be near empty
* at this stage.
*/
+ kmsan_softirq_enter();
__do_softirq();
+ kmsan_softirq_exit();
#else
/*
* Otherwise, irq_exit() is called on the task stack that can
@@ -600,7 +603,9 @@ static void run_ksoftirqd(unsigned int cpu)
* We can safely run softirq on inline stack, as we are not deep
* in the task stack here.
*/
+ kmsan_softirq_enter();
__do_softirq();
+ kmsan_softirq_exit();
local_irq_enable();
cond_resched();
return;
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 0a2ffadc6d71..5f830cee5bfc 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -6,6 +6,7 @@
*
* (C) Copyright 1995 1996 Linus Torvalds
*/
+#include <linux/kmsan.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sched.h>
@@ -214,6 +215,8 @@ int ioremap_page_range(unsigned long addr,
unsigned long start;
unsigned long next;
int err;
+ unsigned long old_addr = addr;
+ phys_addr_t old_phys_addr = phys_addr;
might_sleep();
BUG_ON(addr >= end);
@@ -228,6 +231,8 @@ int ioremap_page_range(unsigned long addr,
} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
flush_cache_vmap(start, end);
+ if (!err)
+ kmsan_ioremap_page_range(old_addr, end, old_phys_addr, prot);
return err;
}
diff --git a/mm/compaction.c b/mm/compaction.c
index 672d3c78c6ab..720a8a4dafec 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -84,6 +84,15 @@ static void split_map_pages(struct list_head *list)
for (i = 0; i < nr_pages; i++) {
list_add(&page->lru, &tmp_list);
+#ifdef CONFIG_KMSAN
+ /*
+ * TODO(glider): we may lose the metadata when copying
+ * something to these pages. Need to allocate shadow
+ * and origin pages here instead.
+ */
+ page->shadow = NULL;
+ page->origin = NULL;
+#endif
page++;
}
}
diff --git a/mm/gup.c b/mm/gup.c
index 8f236a335ae9..8f5f99772278 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -4,6 +4,7 @@
#include <linux/err.h>
#include <linux/spinlock.h>
+#include <linux/kmsan.h>
#include <linux/mm.h>
#include <linux/memremap.h>
#include <linux/pagemap.h>
@@ -2349,6 +2350,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write,
gup_fast_permitted(start, end)) {
local_irq_save(flags);
gup_pgd_range(start, end, write ? FOLL_WRITE : 0, pages, &nr);
+ kmsan_gup_pgd_range(pages, nr);
local_irq_restore(flags);
}
@@ -2418,6 +2420,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages,
gup_fast_permitted(start, end)) {
local_irq_disable();
gup_pgd_range(addr, end, gup_flags, pages, &nr);
+ kmsan_gup_pgd_range(pages, nr);
local_irq_enable();
ret = nr;
}
diff --git a/mm/memory.c b/mm/memory.c
index b1ca51a079f2..48ceacc06e2d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -51,6 +51,7 @@
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/memremap.h>
+#include <linux/kmsan.h>
#include <linux/ksm.h>
#include <linux/rmap.h>
#include <linux/export.h>
@@ -2328,6 +2329,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
if (!new_page)
goto oom;
cow_user_page(new_page, old_page, vmf->address, vma);
+ kmsan_copy_page_meta(new_page, old_page);
}
if (mem_cgroup_try_charge_delay(new_page, mm, GFP_KERNEL, &memcg, false))
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ecc3dbad606b..c98e4441c7c0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -26,6 +26,8 @@
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/kasan.h>
+#include <linux/kmsan.h>
+#include <linux/kmsan-checks.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/pagevec.h>
@@ -1133,6 +1135,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
VM_BUG_ON_PAGE(PageTail(page), page);
trace_mm_page_free(page, order);
+ kmsan_free_page(page, order);
/*
* Check tail pages before head page information is cleared to
@@ -3121,6 +3124,7 @@ void split_page(struct page *page, unsigned int order)
VM_BUG_ON_PAGE(PageCompound(page), page);
VM_BUG_ON_PAGE(!page_count(page), page);
+ kmsan_split_page(page, order);
for (i = 1; i < (1 << order); i++)
set_page_refcounted(page + i);
split_page_owner(page, order);
@@ -3253,6 +3257,13 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone,
/*
* Allocate a page from the given zone. Use pcplists for order-0 allocations.
*/
+/*
+ * TODO(glider): rmqueue() may call __msan_poison_alloca() through a call to
+ * set_pfnblock_flags_mask(). If __msan_poison_alloca() attempts to allocate
+ * pages for the stack depot, it may call rmqueue() again, which will result
+ * in a deadlock.
+ */
+__no_sanitize_memory
static inline
struct page *rmqueue(struct zone *preferred_zone,
struct zone *zone, unsigned int order,
@@ -4781,6 +4792,11 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid,
trace_mm_page_alloc(page, order, alloc_mask, ac.migratetype);
+ if (page)
+ if (kmsan_alloc_page(page, order, gfp_mask)) {
+ __free_pages(page, order);
+ page = NULL;
+ }
return page;
}
EXPORT_SYMBOL(__alloc_pages_nodemask);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a3c70e275f4e..bdf66ffcf02c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -29,6 +29,7 @@
#include <linux/rcupdate.h>
#include <linux/pfn.h>
#include <linux/kmemleak.h>
+#include <linux/kmsan.h>
#include <linux/atomic.h>
#include <linux/compiler.h>
#include <linux/llist.h>
@@ -119,7 +120,8 @@ static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
} while (p4d++, addr = next, addr != end);
}
-static void vunmap_page_range(unsigned long addr, unsigned long end)
+/* Exported for KMSAN, visible in mm/kmsan/kmsan.h only. */
+void __vunmap_page_range(unsigned long addr, unsigned long end)
{
pgd_t *pgd;
unsigned long next;
@@ -133,6 +135,12 @@ static void vunmap_page_range(unsigned long addr, unsigned long end)
vunmap_p4d_range(pgd, addr, next);
} while (pgd++, addr = next, addr != end);
}
+EXPORT_SYMBOL(__vunmap_page_range);
+static void vunmap_page_range(unsigned long addr, unsigned long end)
+{
+ kmsan_vunmap_page_range(addr, end);
+ __vunmap_page_range(addr, end);
+}
static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end, pgprot_t prot, struct page **pages, int *nr)
@@ -216,8 +224,11 @@ static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
* will have pfns corresponding to the "pages" array.
*
* Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
+ *
+ * This function is exported for use in KMSAN, but is only declared in KMSAN
+ * headers.
*/
-static int vmap_page_range_noflush(unsigned long start, unsigned long end,
+int __vmap_page_range_noflush(unsigned long start, unsigned long end,
pgprot_t prot, struct page **pages)
{
pgd_t *pgd;
@@ -237,6 +248,14 @@ static int vmap_page_range_noflush(unsigned long start, unsigned long end,
return nr;
}
+EXPORT_SYMBOL(__vmap_page_range_noflush);
+
+static int vmap_page_range_noflush(unsigned long start, unsigned long end,
+ pgprot_t prot, struct page **pages)
+{
+ kmsan_vmap_page_range_noflush(start, end, prot, pages);
+ return __vmap_page_range_noflush(start, end, prot, pages);
+}
static int vmap_page_range(unsigned long start, unsigned long end,
pgprot_t prot, struct page **pages)
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 17bd8f539bc7..fd22c4a4ba42 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
+#include <linux/kmsan-checks.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/errno.h>
@@ -659,6 +660,7 @@ static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
} else {
qdisc->empty = true;
}
+ kmsan_check_skb(skb);
return skb;
}
--
2.24.0.432.g9d3f5f5b63-goog
