From 9638c0752798c1c9aaf2e56ebaab240eae5eb8dc Mon Sep 17 00:00:00 2001 From: Corinna Vinschen Date: Fri, 1 Dec 2017 13:47:26 +0100 Subject: [PATCH] newlib: vf[w]scanf: Drop width computation mixup The width value keeps the maximum field width. This is the maximum field width of the *input*. It's *never* to be used in conjunction with the number of bytes or characters written to the output argument. However, especially in vfwscanf, the code is partially taken from NetBSD which erroneously subtracts the number of multibyte chars written to the argument from the width variable, thus potentially subtracting up to MB_CUR_MAX from width for a single character in the input stream. To make matters worse, the previous patch adding %m added basically the same mistake for 'c' type input. Fix it. Signed-off-by: Corinna Vinschen --- newlib/libc/stdio/vfscanf.c | 19 +++++--- newlib/libc/stdio/vfwscanf.c | 95 ++++++++++++------------------------ 2 files changed, 44 insertions(+), 70 deletions(-) diff --git a/newlib/libc/stdio/vfscanf.c b/newlib/libc/stdio/vfscanf.c index 23d73916a..e8e4dab2e 100644 --- a/newlib/libc/stdio/vfscanf.c +++ b/newlib/libc/stdio/vfscanf.c @@ -945,7 +945,7 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), #ifdef _WANT_IO_POSIX_EXTENSIONS wchar_t **wcp_p = NULL; wchar_t *wcp0 = NULL; - size_t width0 = 0; + size_t wcp_siz = 0; #endif mbstate_t state; memset (&state, 0, sizeof (mbstate_t)); @@ -953,12 +953,12 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), wcp = NULL; #ifdef _WANT_IO_POSIX_EXTENSIONS else if (flags & MALLOC) - width0 = alloc_m_ptr (wchar_t, wcp, wcp0, wcp_p, width); + wcp_siz = alloc_m_ptr (wchar_t, wcp, wcp0, wcp_p, 32); #endif else wcp = GET_ARG (N, ap, wchar_t *); n = 0; - while (width != 0) + while (width-- != 0) { if (n == MB_CUR_MAX) goto input_failure; @@ -973,9 +973,14 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), if (mbslen != (size_t)-2) /* Incomplete sequence */ { nread += n; - width -= 1; if (!(flags & SUPPRESS)) - wcp += 1; + { +#ifdef _WANT_IO_POSIX_EXTENSIONS + wcp_siz = realloc_m_ptr (wchar_t, wcp, wcp0, wcp_p, + wcp_siz); +#endif + wcp++; + } n = 0; } if (BufferEmpty) @@ -986,7 +991,7 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), } } #ifdef _WANT_IO_POSIX_EXTENSIONS - shrink_m_ptr (wchar_t, wcp_p, width0 - width, width0); + shrink_m_ptr (wchar_t, wcp_p, wcp - wcp0, wcp_siz); #endif if (!(flags & SUPPRESS)) nassigned++; @@ -1134,6 +1139,7 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), buf[n++] = *fp->_p; fp->_r -= 1; fp->_p += 1; + width--; if ((mbslen = _mbrtowc_r (rptr, wcp, buf, n, &state)) == (size_t)-1) goto input_failure; @@ -1148,7 +1154,6 @@ _DEFUN(__SVFSCANF_R, (rptr, fp, fmt0, ap), break; } nread += n; - width -= 1; if ((flags & SUPPRESS) == 0) { wcp += 1; diff --git a/newlib/libc/stdio/vfwscanf.c b/newlib/libc/stdio/vfwscanf.c index 46c156694..a317eae44 100644 --- a/newlib/libc/stdio/vfwscanf.c +++ b/newlib/libc/stdio/vfwscanf.c @@ -376,7 +376,6 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), wint_t wi; /* handy wint_t */ char *mbp = NULL; /* multibyte string pointer for %c %s %[ */ size_t nconv; /* number of bytes in mb. conversion */ - char mbbuf[MB_LEN_MAX]; /* temporary mb. character buffer */ char *cp; short *sp; @@ -884,14 +883,14 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), #ifdef _WANT_IO_POSIX_EXTENSIONS wchar_t **p_p = NULL; wchar_t *p0 = NULL; - size_t width0 = 0; + size_t p_siz = 0; #endif if (flags & SUPPRESS) ; #ifdef _WANT_IO_POSIX_EXTENSIONS else if (flags & MALLOC) - width0 = alloc_m_ptr (wchar_t, p, p0, p_p, width); + p_siz = alloc_m_ptr (wchar_t, p, p0, p_p, 32); #endif else p = GET_ARG(N, ap, wchar_t *); @@ -899,14 +898,20 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), while (width-- != 0 && (wi = _fgetwc_r (rptr, fp)) != WEOF) { if (!(flags & SUPPRESS)) - *p++ = (wchar_t) wi; + { +#ifdef _WANT_IO_POSIX_EXTENSIONS + /* Check before ++ because we never add a \0 */ + p_siz = realloc_m_ptr (wchar_t, p, p0, p_p, p_siz); +#endif + *p++ = (wchar_t) wi; + } n++; } if (n == 0) goto input_failure; nread += n; #ifdef _WANT_IO_POSIX_EXTENSIONS - shrink_m_ptr (wchar_t, p_p, width0 - width, width0); + shrink_m_ptr (wchar_t, p_p, p - p0, p_siz); #endif if (!(flags & SUPPRESS)) nassigned++; @@ -916,50 +921,38 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), #ifdef _WANT_IO_POSIX_EXTENSIONS char **mbp_p = NULL; char *mbp0 = NULL; - size_t width0 = 0; + size_t mbp_siz = 0; #endif if (flags & SUPPRESS) ; #ifdef _WANT_IO_POSIX_EXTENSIONS else if (flags & MALLOC) - width0 = alloc_m_ptr (char, mbp, mbp0, mbp_p, width); + mbp_siz = alloc_m_ptr (char, mbp, mbp0, mbp_p, 32); #endif else mbp = GET_ARG(N, ap, char *); n = 0; memset ((_PTR)&mbs, '\0', sizeof (mbstate_t)); - while (width != 0 && (wi = _fgetwc_r (rptr, fp)) != WEOF) + while (width-- != 0 && (wi = _fgetwc_r (rptr, fp)) != WEOF) { - if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) +#ifdef _WANT_IO_POSIX_EXTENSIONS + mbp_siz = realloc_m_ptr (char, mbp, mbp0, mbp_p, mbp_siz); +#endif + if (!(flags & SUPPRESS)) { nconv = _wcrtomb_r (rptr, mbp, wi, &mbs); if (nconv == (size_t) -1) goto input_failure; + mbp += nconv; } - else - { - nconv = _wcrtomb_r (rptr, mbbuf, wi, &mbs); - if (nconv == (size_t) -1) - goto input_failure; - if (nconv > width) - { - _ungetwc_r (rptr, wi, fp); - break; - } - if (!(flags & SUPPRESS)) - memcpy(mbp, mbbuf, nconv); - } - if (!(flags & SUPPRESS)) - mbp += nconv; - width -= nconv; n++; } if (n == 0) goto input_failure; nread += n; #ifdef _WANT_IO_POSIX_EXTENSIONS - shrink_m_ptr (char, mbp_p, width0 - width, width0); + shrink_m_ptr (char, mbp_p, mbp - mbp0, mbp_siz); #endif if (!(flags & SUPPRESS)) nassigned++; @@ -1031,30 +1024,18 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), n = 0; memset ((_PTR) &mbs, '\0', sizeof (mbstate_t)); while ((wi = _fgetwc_r (rptr, fp)) != WEOF - && width != 0 && INCCL (wi)) + && width-- != 0 && INCCL (wi)) { -#ifdef _WANT_IO_POSIX_EXTENSIONS - mbp_siz = realloc_m_ptr (char, mbp, mbp0, mbp_p, mbp_siz); -#endif - if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) + if (!(flags & SUPPRESS)) { nconv = _wcrtomb_r (rptr, mbp, wi, &mbs); if (nconv == (size_t) -1) goto input_failure; + mbp += nconv; +#ifdef _WANT_IO_POSIX_EXTENSIONS + mbp_siz = realloc_m_ptr (char, mbp, mbp0, mbp_p, mbp_siz); +#endif } - else - { - nconv = wcrtomb(mbbuf, wi, &mbs); - if (nconv == (size_t) -1) - goto input_failure; - if (nconv > width) - break; - if (!(flags & SUPPRESS)) - memcpy(mbp, mbbuf, nconv); - } - if (!(flags & SUPPRESS)) - mbp += nconv; - width -= nconv; n++; } if (wi != WEOF) @@ -1098,10 +1079,10 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), && width-- != 0 && !iswspace (wi)) { *p++ = (wchar_t) wi; - nread++; #ifdef _WANT_IO_POSIX_EXTENSIONS p_siz = realloc_m_ptr (wchar_t, p, p0, p_p, p_siz); #endif + nread++; } if (wi != WEOF) _ungetwc_r (rptr, wi, fp); @@ -1129,30 +1110,18 @@ _DEFUN(__SVFWSCANF_R, (rptr, fp, fmt0, ap), mbp = GET_ARG(N, ap, char *); memset ((_PTR) &mbs, '\0', sizeof (mbstate_t)); while ((wi = _fgetwc_r (rptr, fp)) != WEOF - && width != 0 && !iswspace (wi)) + && width-- != 0 && !iswspace (wi)) { -#ifdef _WANT_IO_POSIX_EXTENSIONS - mbp_siz = realloc_m_ptr (char, mbp, mbp0, mbp_p, mbp_siz); -#endif - if (width >= MB_CUR_MAX && !(flags & SUPPRESS)) + if (!(flags & SUPPRESS)) { nconv = wcrtomb(mbp, wi, &mbs); if (nconv == (size_t)-1) goto input_failure; + mbp += nconv; +#ifdef _WANT_IO_POSIX_EXTENSIONS + mbp_siz = realloc_m_ptr (char, mbp, mbp0, mbp_p, mbp_siz); +#endif } - else - { - nconv = wcrtomb(mbbuf, wi, &mbs); - if (nconv == (size_t)-1) - goto input_failure; - if (nconv > width) - break; - if (!(flags & SUPPRESS)) - memcpy(mbp, mbbuf, nconv); - } - if (!(flags & SUPPRESS)) - mbp += nconv; - width -= nconv; nread++; } if (wi != WEOF)