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-rw-r--r--lib/iov_iter.c98
1 files changed, 69 insertions, 29 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index c9a69064462f..52c8dd6d8e82 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -130,6 +130,24 @@
} \
}
+static int copyout(void __user *to, const void *from, size_t n)
+{
+ if (access_ok(VERIFY_WRITE, to, n)) {
+ kasan_check_read(from, n);
+ n = raw_copy_to_user(to, from, n);
+ }
+ return n;
+}
+
+static int copyin(void *to, const void __user *from, size_t n)
+{
+ if (access_ok(VERIFY_READ, from, n)) {
+ kasan_check_write(to, n);
+ n = raw_copy_from_user(to, from, n);
+ }
+ return n;
+}
+
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -144,6 +162,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
if (unlikely(!bytes))
return 0;
+ might_fault();
wanted = bytes;
iov = i->iov;
skip = i->iov_offset;
@@ -155,7 +174,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
from = kaddr + offset;
/* first chunk, usually the only one */
- left = __copy_to_user_inatomic(buf, from, copy);
+ left = copyout(buf, from, copy);
copy -= left;
skip += copy;
from += copy;
@@ -165,7 +184,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
iov++;
buf = iov->iov_base;
copy = min(bytes, iov->iov_len);
- left = __copy_to_user_inatomic(buf, from, copy);
+ left = copyout(buf, from, copy);
copy -= left;
skip = copy;
from += copy;
@@ -184,7 +203,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
kaddr = kmap(page);
from = kaddr + offset;
- left = __copy_to_user(buf, from, copy);
+ left = copyout(buf, from, copy);
copy -= left;
skip += copy;
from += copy;
@@ -193,7 +212,7 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b
iov++;
buf = iov->iov_base;
copy = min(bytes, iov->iov_len);
- left = __copy_to_user(buf, from, copy);
+ left = copyout(buf, from, copy);
copy -= left;
skip = copy;
from += copy;
@@ -227,6 +246,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
if (unlikely(!bytes))
return 0;
+ might_fault();
wanted = bytes;
iov = i->iov;
skip = i->iov_offset;
@@ -238,7 +258,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
to = kaddr + offset;
/* first chunk, usually the only one */
- left = __copy_from_user_inatomic(to, buf, copy);
+ left = copyin(to, buf, copy);
copy -= left;
skip += copy;
to += copy;
@@ -248,7 +268,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
iov++;
buf = iov->iov_base;
copy = min(bytes, iov->iov_len);
- left = __copy_from_user_inatomic(to, buf, copy);
+ left = copyin(to, buf, copy);
copy -= left;
skip = copy;
to += copy;
@@ -267,7 +287,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
kaddr = kmap(page);
to = kaddr + offset;
- left = __copy_from_user(to, buf, copy);
+ left = copyin(to, buf, copy);
copy -= left;
skip += copy;
to += copy;
@@ -276,7 +296,7 @@ static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, size_t
iov++;
buf = iov->iov_base;
copy = min(bytes, iov->iov_len);
- left = __copy_from_user(to, buf, copy);
+ left = copyin(to, buf, copy);
copy -= left;
skip = copy;
to += copy;
@@ -535,14 +555,15 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
return bytes;
}
-size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
if (unlikely(i->type & ITER_PIPE))
return copy_pipe_to_iter(addr, bytes, i);
+ if (iter_is_iovec(i))
+ might_fault();
iterate_and_advance(i, bytes, v,
- __copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
- v.iov_len),
+ copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
memcpy_to_page(v.bv_page, v.bv_offset,
(from += v.bv_len) - v.bv_len, v.bv_len),
memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
@@ -550,18 +571,19 @@ size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL(copy_to_iter);
+EXPORT_SYMBOL(_copy_to_iter);
-size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
if (unlikely(i->type & ITER_PIPE)) {
WARN_ON(1);
return 0;
}
+ if (iter_is_iovec(i))
+ might_fault();
iterate_and_advance(i, bytes, v,
- __copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
- v.iov_len),
+ copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
v.bv_offset, v.bv_len),
memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
@@ -569,9 +591,9 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL(copy_from_iter);
+EXPORT_SYMBOL(_copy_from_iter);
-bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
if (unlikely(i->type & ITER_PIPE)) {
@@ -581,8 +603,10 @@ bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
if (unlikely(i->count < bytes))
return false;
+ if (iter_is_iovec(i))
+ might_fault();
iterate_all_kinds(i, bytes, v, ({
- if (__copy_from_user((to += v.iov_len) - v.iov_len,
+ if (copyin((to += v.iov_len) - v.iov_len,
v.iov_base, v.iov_len))
return false;
0;}),
@@ -594,9 +618,9 @@ bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
iov_iter_advance(i, bytes);
return true;
}
-EXPORT_SYMBOL(copy_from_iter_full);
+EXPORT_SYMBOL(_copy_from_iter_full);
-size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
if (unlikely(i->type & ITER_PIPE)) {
@@ -613,10 +637,10 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL(copy_from_iter_nocache);
+EXPORT_SYMBOL(_copy_from_iter_nocache);
#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
-size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
+size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
if (unlikely(i->type & ITER_PIPE)) {
@@ -634,10 +658,10 @@ size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
return bytes;
}
-EXPORT_SYMBOL_GPL(copy_from_iter_flushcache);
+EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);
#endif
-bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
+bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
if (unlikely(i->type & ITER_PIPE)) {
@@ -659,11 +683,22 @@ bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
iov_iter_advance(i, bytes);
return true;
}
-EXPORT_SYMBOL(copy_from_iter_full_nocache);
+EXPORT_SYMBOL(_copy_from_iter_full_nocache);
+
+static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)
+{
+ size_t v = n + offset;
+ if (likely(n <= v && v <= (PAGE_SIZE << compound_order(page))))
+ return true;
+ WARN_ON(1);
+ return false;
+}
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
+ if (unlikely(!page_copy_sane(page, offset, bytes)))
+ return 0;
if (i->type & (ITER_BVEC|ITER_KVEC)) {
void *kaddr = kmap_atomic(page);
size_t wanted = copy_to_iter(kaddr + offset, bytes, i);
@@ -679,13 +714,15 @@ EXPORT_SYMBOL(copy_page_to_iter);
size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
+ if (unlikely(!page_copy_sane(page, offset, bytes)))
+ return 0;
if (unlikely(i->type & ITER_PIPE)) {
WARN_ON(1);
return 0;
}
if (i->type & (ITER_BVEC|ITER_KVEC)) {
void *kaddr = kmap_atomic(page);
- size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+ size_t wanted = _copy_from_iter(kaddr + offset, bytes, i);
kunmap_atomic(kaddr);
return wanted;
} else
@@ -722,7 +759,7 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
if (unlikely(i->type & ITER_PIPE))
return pipe_zero(bytes, i);
iterate_and_advance(i, bytes, v,
- __clear_user(v.iov_base, v.iov_len),
+ clear_user(v.iov_base, v.iov_len),
memzero_page(v.bv_page, v.bv_offset, v.bv_len),
memset(v.iov_base, 0, v.iov_len)
)
@@ -735,14 +772,17 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes)
{
char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+ if (unlikely(!page_copy_sane(page, offset, bytes))) {
+ kunmap_atomic(kaddr);
+ return 0;
+ }
if (unlikely(i->type & ITER_PIPE)) {
kunmap_atomic(kaddr);
WARN_ON(1);
return 0;
}
iterate_all_kinds(i, bytes, v,
- __copy_from_user_inatomic((p += v.iov_len) - v.iov_len,
- v.iov_base, v.iov_len),
+ copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
v.bv_offset, v.bv_len),
memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.