diff options
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 34 |
1 files changed, 18 insertions, 16 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index ae711f1d7a83..c2ed7dcf494e 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1289,13 +1289,11 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx, __wake_userfault(ctx, range); } -static __always_inline int validate_range(struct mm_struct *mm, - __u64 start, __u64 len) +static __always_inline int validate_unaligned_range( + struct mm_struct *mm, __u64 start, __u64 len) { __u64 task_size = mm->task_size; - if (start & ~PAGE_MASK) - return -EINVAL; if (len & ~PAGE_MASK) return -EINVAL; if (!len) @@ -1306,9 +1304,20 @@ static __always_inline int validate_range(struct mm_struct *mm, return -EINVAL; if (len > task_size - start) return -EINVAL; + if (start + len <= start) + return -EINVAL; return 0; } +static __always_inline int validate_range(struct mm_struct *mm, + __u64 start, __u64 len) +{ + if (start & ~PAGE_MASK) + return -EINVAL; + + return validate_unaligned_range(mm, start, len); +} + static int userfaultfd_register(struct userfaultfd_ctx *ctx, unsigned long arg) { @@ -1757,17 +1766,15 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, sizeof(uffdio_copy)-sizeof(__s64))) goto out; + ret = validate_unaligned_range(ctx->mm, uffdio_copy.src, + uffdio_copy.len); + if (ret) + goto out; ret = validate_range(ctx->mm, uffdio_copy.dst, uffdio_copy.len); if (ret) goto out; - /* - * double check for wraparound just in case. copy_from_user() - * will later check uffdio_copy.src + uffdio_copy.len to fit - * in the userland range. - */ + ret = -EINVAL; - if (uffdio_copy.src + uffdio_copy.len <= uffdio_copy.src) - goto out; if (uffdio_copy.mode & ~(UFFDIO_COPY_MODE_DONTWAKE|UFFDIO_COPY_MODE_WP)) goto out; if (uffdio_copy.mode & UFFDIO_COPY_MODE_WP) @@ -1927,11 +1934,6 @@ static int userfaultfd_continue(struct userfaultfd_ctx *ctx, unsigned long arg) goto out; ret = -EINVAL; - /* double check for wraparound just in case. */ - if (uffdio_continue.range.start + uffdio_continue.range.len <= - uffdio_continue.range.start) { - goto out; - } if (uffdio_continue.mode & ~(UFFDIO_CONTINUE_MODE_DONTWAKE | UFFDIO_CONTINUE_MODE_WP)) goto out; |