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-rw-r--r--lib/generic-radix-tree.c32
-rw-r--r--lib/string.c21
-rw-r--r--lib/strnlen_user.c8
-rw-r--r--lib/test_meminit.c27
-rw-r--r--lib/test_user_copy.c155
-rw-r--r--lib/textsearch.c4
-rw-r--r--lib/usercopy.c55
-rw-r--r--lib/vdso/Kconfig9
8 files changed, 260 insertions, 51 deletions
diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c
index ae25e2fa2187..f25eb111c051 100644
--- a/lib/generic-radix-tree.c
+++ b/lib/generic-radix-tree.c
@@ -2,6 +2,7 @@
#include <linux/export.h>
#include <linux/generic-radix-tree.h>
#include <linux/gfp.h>
+#include <linux/kmemleak.h>
#define GENRADIX_ARY (PAGE_SIZE / sizeof(struct genradix_node *))
#define GENRADIX_ARY_SHIFT ilog2(GENRADIX_ARY)
@@ -75,6 +76,27 @@ void *__genradix_ptr(struct __genradix *radix, size_t offset)
}
EXPORT_SYMBOL(__genradix_ptr);
+static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask)
+{
+ struct genradix_node *node;
+
+ node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO);
+
+ /*
+ * We're using pages (not slab allocations) directly for kernel data
+ * structures, so we need to explicitly inform kmemleak of them in order
+ * to avoid false positive memory leak reports.
+ */
+ kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask);
+ return node;
+}
+
+static inline void genradix_free_node(struct genradix_node *node)
+{
+ kmemleak_free(node);
+ free_page((unsigned long)node);
+}
+
/*
* Returns pointer to the specified byte @offset within @radix, allocating it if
* necessary - newly allocated slots are always zeroed out:
@@ -97,8 +119,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
break;
if (!new_node) {
- new_node = (void *)
- __get_free_page(gfp_mask|__GFP_ZERO);
+ new_node = genradix_alloc_node(gfp_mask);
if (!new_node)
return NULL;
}
@@ -121,8 +142,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
n = READ_ONCE(*p);
if (!n) {
if (!new_node) {
- new_node = (void *)
- __get_free_page(gfp_mask|__GFP_ZERO);
+ new_node = genradix_alloc_node(gfp_mask);
if (!new_node)
return NULL;
}
@@ -133,7 +153,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
}
if (new_node)
- free_page((unsigned long) new_node);
+ genradix_free_node(new_node);
return &n->data[offset];
}
@@ -191,7 +211,7 @@ static void genradix_free_recurse(struct genradix_node *n, unsigned level)
genradix_free_recurse(n->children[i], level - 1);
}
- free_page((unsigned long) n);
+ genradix_free_node(n);
}
int __genradix_prealloc(struct __genradix *radix, size_t size,
diff --git a/lib/string.c b/lib/string.c
index cd7a10c19210..08ec58cc673b 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -748,27 +748,6 @@ void *memset(void *s, int c, size_t count)
EXPORT_SYMBOL(memset);
#endif
-/**
- * memzero_explicit - Fill a region of memory (e.g. sensitive
- * keying data) with 0s.
- * @s: Pointer to the start of the area.
- * @count: The size of the area.
- *
- * Note: usually using memset() is just fine (!), but in cases
- * where clearing out _local_ data at the end of a scope is
- * necessary, memzero_explicit() should be used instead in
- * order to prevent the compiler from optimising away zeroing.
- *
- * memzero_explicit() doesn't need an arch-specific version as
- * it just invokes the one of memset() implicitly.
- */
-void memzero_explicit(void *s, size_t count)
-{
- memset(s, 0, count);
- barrier_data(s);
-}
-EXPORT_SYMBOL(memzero_explicit);
-
#ifndef __HAVE_ARCH_MEMSET16
/**
* memset16() - Fill a memory area with a uint16_t
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 28ff554a1be8..6c0005d5dd5c 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -3,16 +3,10 @@
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/mm.h>
+#include <linux/bitops.h>
#include <asm/word-at-a-time.h>
-/* Set bits in the first 'n' bytes when loaded from memory */
-#ifdef __LITTLE_ENDIAN
-# define aligned_byte_mask(n) ((1ul << 8*(n))-1)
-#else
-# define aligned_byte_mask(n) (~0xfful << (BITS_PER_LONG - 8 - 8*(n)))
-#endif
-
/*
* Do a strnlen, return length of string *with* final '\0'.
* 'count' is the user-supplied count, while 'max' is the
diff --git a/lib/test_meminit.c b/lib/test_meminit.c
index 9729f271d150..9742e5cb853a 100644
--- a/lib/test_meminit.c
+++ b/lib/test_meminit.c
@@ -297,6 +297,32 @@ out:
return 1;
}
+static int __init do_kmem_cache_size_bulk(int size, int *total_failures)
+{
+ struct kmem_cache *c;
+ int i, iter, maxiter = 1024;
+ int num, bytes;
+ bool fail = false;
+ void *objects[10];
+
+ c = kmem_cache_create("test_cache", size, size, 0, NULL);
+ for (iter = 0; (iter < maxiter) && !fail; iter++) {
+ num = kmem_cache_alloc_bulk(c, GFP_KERNEL, ARRAY_SIZE(objects),
+ objects);
+ for (i = 0; i < num; i++) {
+ bytes = count_nonzero_bytes(objects[i], size);
+ if (bytes)
+ fail = true;
+ fill_with_garbage(objects[i], size);
+ }
+
+ if (num)
+ kmem_cache_free_bulk(c, num, objects);
+ }
+ *total_failures += fail;
+ return 1;
+}
+
/*
* Test kmem_cache allocation by creating caches of different sizes, with and
* without constructors, with and without SLAB_TYPESAFE_BY_RCU.
@@ -318,6 +344,7 @@ static int __init test_kmemcache(int *total_failures)
num_tests += do_kmem_cache_size(size, ctor, rcu, zero,
&failures);
}
+ num_tests += do_kmem_cache_size_bulk(size, &failures);
}
REPORT_FAILURES_IN_FN();
*total_failures += failures;
diff --git a/lib/test_user_copy.c b/lib/test_user_copy.c
index 67bcd5dfd847..5ff04d8fe971 100644
--- a/lib/test_user_copy.c
+++ b/lib/test_user_copy.c
@@ -31,14 +31,152 @@
# define TEST_U64
#endif
-#define test(condition, msg) \
-({ \
- int cond = (condition); \
- if (cond) \
- pr_warn("%s\n", msg); \
- cond; \
+#define test(condition, msg, ...) \
+({ \
+ int cond = (condition); \
+ if (cond) \
+ pr_warn("[%d] " msg "\n", __LINE__, ##__VA_ARGS__); \
+ cond; \
})
+static bool is_zeroed(void *from, size_t size)
+{
+ return memchr_inv(from, 0x0, size) == NULL;
+}
+
+static int test_check_nonzero_user(char *kmem, char __user *umem, size_t size)
+{
+ int ret = 0;
+ size_t start, end, i, zero_start, zero_end;
+
+ if (test(size < 2 * PAGE_SIZE, "buffer too small"))
+ return -EINVAL;
+
+ /*
+ * We want to cross a page boundary to exercise the code more
+ * effectively. We also don't want to make the size we scan too large,
+ * otherwise the test can take a long time and cause soft lockups. So
+ * scan a 1024 byte region across the page boundary.
+ */
+ size = 1024;
+ start = PAGE_SIZE - (size / 2);
+
+ kmem += start;
+ umem += start;
+
+ zero_start = size / 4;
+ zero_end = size - zero_start;
+
+ /*
+ * We conduct a series of check_nonzero_user() tests on a block of
+ * memory with the following byte-pattern (trying every possible
+ * [start,end] pair):
+ *
+ * [ 00 ff 00 ff ... 00 00 00 00 ... ff 00 ff 00 ]
+ *
+ * And we verify that check_nonzero_user() acts identically to
+ * memchr_inv().
+ */
+
+ memset(kmem, 0x0, size);
+ for (i = 1; i < zero_start; i += 2)
+ kmem[i] = 0xff;
+ for (i = zero_end; i < size; i += 2)
+ kmem[i] = 0xff;
+
+ ret |= test(copy_to_user(umem, kmem, size),
+ "legitimate copy_to_user failed");
+
+ for (start = 0; start <= size; start++) {
+ for (end = start; end <= size; end++) {
+ size_t len = end - start;
+ int retval = check_zeroed_user(umem + start, len);
+ int expected = is_zeroed(kmem + start, len);
+
+ ret |= test(retval != expected,
+ "check_nonzero_user(=%d) != memchr_inv(=%d) mismatch (start=%zu, end=%zu)",
+ retval, expected, start, end);
+ }
+ }
+
+ return ret;
+}
+
+static int test_copy_struct_from_user(char *kmem, char __user *umem,
+ size_t size)
+{
+ int ret = 0;
+ char *umem_src = NULL, *expected = NULL;
+ size_t ksize, usize;
+
+ umem_src = kmalloc(size, GFP_KERNEL);
+ ret = test(umem_src == NULL, "kmalloc failed");
+ if (ret)
+ goto out_free;
+
+ expected = kmalloc(size, GFP_KERNEL);
+ ret = test(expected == NULL, "kmalloc failed");
+ if (ret)
+ goto out_free;
+
+ /* Fill umem with a fixed byte pattern. */
+ memset(umem_src, 0x3e, size);
+ ret |= test(copy_to_user(umem, umem_src, size),
+ "legitimate copy_to_user failed");
+
+ /* Check basic case -- (usize == ksize). */
+ ksize = size;
+ usize = size;
+
+ memcpy(expected, umem_src, ksize);
+
+ memset(kmem, 0x0, size);
+ ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+ "copy_struct_from_user(usize == ksize) failed");
+ ret |= test(memcmp(kmem, expected, ksize),
+ "copy_struct_from_user(usize == ksize) gives unexpected copy");
+
+ /* Old userspace case -- (usize < ksize). */
+ ksize = size;
+ usize = size / 2;
+
+ memcpy(expected, umem_src, usize);
+ memset(expected + usize, 0x0, ksize - usize);
+
+ memset(kmem, 0x0, size);
+ ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+ "copy_struct_from_user(usize < ksize) failed");
+ ret |= test(memcmp(kmem, expected, ksize),
+ "copy_struct_from_user(usize < ksize) gives unexpected copy");
+
+ /* New userspace (-E2BIG) case -- (usize > ksize). */
+ ksize = size / 2;
+ usize = size;
+
+ memset(kmem, 0x0, size);
+ ret |= test(copy_struct_from_user(kmem, ksize, umem, usize) != -E2BIG,
+ "copy_struct_from_user(usize > ksize) didn't give E2BIG");
+
+ /* New userspace (success) case -- (usize > ksize). */
+ ksize = size / 2;
+ usize = size;
+
+ memcpy(expected, umem_src, ksize);
+ ret |= test(clear_user(umem + ksize, usize - ksize),
+ "legitimate clear_user failed");
+
+ memset(kmem, 0x0, size);
+ ret |= test(copy_struct_from_user(kmem, ksize, umem, usize),
+ "copy_struct_from_user(usize > ksize) failed");
+ ret |= test(memcmp(kmem, expected, ksize),
+ "copy_struct_from_user(usize > ksize) gives unexpected copy");
+
+out_free:
+ kfree(expected);
+ kfree(umem_src);
+ return ret;
+}
+
static int __init test_user_copy_init(void)
{
int ret = 0;
@@ -106,6 +244,11 @@ static int __init test_user_copy_init(void)
#endif
#undef test_legit
+ /* Test usage of check_nonzero_user(). */
+ ret |= test_check_nonzero_user(kmem, usermem, 2 * PAGE_SIZE);
+ /* Test usage of copy_struct_from_user(). */
+ ret |= test_copy_struct_from_user(kmem, usermem, 2 * PAGE_SIZE);
+
/*
* Invalid usage: none of these copies should succeed.
*/
diff --git a/lib/textsearch.c b/lib/textsearch.c
index 4f16eec5d554..f68dea8806be 100644
--- a/lib/textsearch.c
+++ b/lib/textsearch.c
@@ -89,9 +89,9 @@
* goto errout;
* }
*
- * pos = textsearch_find_continuous(conf, \&state, example, strlen(example));
+ * pos = textsearch_find_continuous(conf, &state, example, strlen(example));
* if (pos != UINT_MAX)
- * panic("Oh my god, dancing chickens at \%d\n", pos);
+ * panic("Oh my god, dancing chickens at %d\n", pos);
*
* textsearch_destroy(conf);
*/
diff --git a/lib/usercopy.c b/lib/usercopy.c
index c2bfbcaeb3dc..cbb4d9ec00f2 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/uaccess.h>
+#include <linux/bitops.h>
/* out-of-line parts */
@@ -31,3 +32,57 @@ unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n)
}
EXPORT_SYMBOL(_copy_to_user);
#endif
+
+/**
+ * check_zeroed_user: check if a userspace buffer only contains zero bytes
+ * @from: Source address, in userspace.
+ * @size: Size of buffer.
+ *
+ * This is effectively shorthand for "memchr_inv(from, 0, size) == NULL" for
+ * userspace addresses (and is more efficient because we don't care where the
+ * first non-zero byte is).
+ *
+ * Returns:
+ * * 0: There were non-zero bytes present in the buffer.
+ * * 1: The buffer was full of zero bytes.
+ * * -EFAULT: access to userspace failed.
+ */
+int check_zeroed_user(const void __user *from, size_t size)
+{
+ unsigned long val;
+ uintptr_t align = (uintptr_t) from % sizeof(unsigned long);
+
+ if (unlikely(size == 0))
+ return 1;
+
+ from -= align;
+ size += align;
+
+ if (!user_access_begin(from, size))
+ return -EFAULT;
+
+ unsafe_get_user(val, (unsigned long __user *) from, err_fault);
+ if (align)
+ val &= ~aligned_byte_mask(align);
+
+ while (size > sizeof(unsigned long)) {
+ if (unlikely(val))
+ goto done;
+
+ from += sizeof(unsigned long);
+ size -= sizeof(unsigned long);
+
+ unsafe_get_user(val, (unsigned long __user *) from, err_fault);
+ }
+
+ if (size < sizeof(unsigned long))
+ val &= aligned_byte_mask(size);
+
+done:
+ user_access_end();
+ return (val == 0);
+err_fault:
+ user_access_end();
+ return -EFAULT;
+}
+EXPORT_SYMBOL(check_zeroed_user);
diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index cc00364bd2c2..9fe698ff62ec 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -24,13 +24,4 @@ config GENERIC_COMPAT_VDSO
help
This config option enables the compat VDSO layer.
-config CROSS_COMPILE_COMPAT_VDSO
- string "32 bit Toolchain prefix for compat vDSO"
- default ""
- depends on GENERIC_COMPAT_VDSO
- help
- Defines the cross-compiler prefix for compiling compat vDSO.
- If a 64 bit compiler (i.e. x86_64) can compile the VDSO for
- 32 bit, it does not need to define this parameter.
-
endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.