From aa28de275a248879f9828cb9f7ee7e119c72ff96 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 29 Jun 2017 21:45:10 -0400 Subject: [PATCH] iov_iter/hardening: move object size checks to inlined part There we actually have useful information about object sizes. Note: this patch has them done for all iov_iter flavours. Right now we do them twice in iovec case, but that'll change very shortly. Signed-off-by: Al Viro --- include/linux/uio.h | 58 +++++++++++++++++++++++++++++++++++++++++---- lib/iov_iter.c | 22 ++++++++--------- 2 files changed, 64 insertions(+), 16 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index f2d36a3d3005..243e2362fe1a 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -10,6 +10,7 @@ #define __LINUX_UIO_H #include +#include #include struct page; @@ -91,11 +92,58 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); -size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); -size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); -bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); -size_t copy_from_iter_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); + +size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); +size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); +bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); +size_t _copy_from_iter_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); + +static __always_inline __must_check +size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, true))) + return bytes; + else + return _copy_to_iter(addr, bytes, i); +} + +static __always_inline __must_check +size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, false))) + return bytes; + else + return _copy_from_iter(addr, bytes, i); +} + +static __always_inline __must_check +bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, false))) + return false; + else + return _copy_from_iter_full(addr, bytes, i); +} + +static __always_inline __must_check +size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, false))) + return bytes; + else + return _copy_from_iter_nocache(addr, bytes, i); +} + +static __always_inline __must_check +bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, false))) + return false; + else + return _copy_from_iter_full_nocache(addr, bytes, i); +} + size_t iov_iter_zero(size_t bytes, struct iov_iter *); unsigned long iov_iter_alignment(const struct iov_iter *i); unsigned long iov_iter_gap_alignment(const struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index f835964c9485..bc4a63ebe91a 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -535,7 +535,7 @@ 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)) @@ -550,9 +550,9 @@ 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)) { @@ -569,9 +569,9 @@ 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)) { @@ -594,9 +594,9 @@ 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)) { @@ -613,9 +613,9 @@ 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); -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)) { @@ -637,7 +637,7 @@ 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); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) @@ -663,7 +663,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, } 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