diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/strnlen_user.c | 12 | ||||
| -rw-r--r-- | lib/swiotlb.c | 5 |
2 files changed, 13 insertions, 4 deletions
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index a28df5206d95..fe9a32591c24 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -57,7 +57,8 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, return res + find_zero(data) + 1 - align; } res += sizeof(unsigned long); - if (unlikely(max < sizeof(unsigned long))) + /* We already handled 'unsigned long' bytes. Did we do it all ? */ + if (unlikely(max <= sizeof(unsigned long))) break; max -= sizeof(unsigned long); if (unlikely(__get_user(c,(unsigned long __user *)(src+res)))) @@ -89,8 +90,15 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. - * If the string is too long, returns 'count+1'. + * If the string is too long, returns a number larger than @count. User + * has to check the return value against "> count". * On exception (or invalid count), returns 0. + * + * NOTE! You should basically never use this function. There is + * almost never any valid case for using the length of a user space + * string, since the string can be changed at any time by other + * threads. Use "strncpy_from_user()" instead to get a stable copy + * of the string. */ long strnlen_user(const char __user *str, long count) { diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 4abda074ea45..3c365ab6cf5f 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -537,8 +537,9 @@ EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single); * Allocates bounce buffer and returns its kernel virtual address. */ -phys_addr_t map_single(struct device *hwdev, phys_addr_t phys, size_t size, - enum dma_data_direction dir) +static phys_addr_t +map_single(struct device *hwdev, phys_addr_t phys, size_t size, + enum dma_data_direction dir) { dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start); |