diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | NEWS | 3 | ||||
| -rw-r--r-- | stdio-common/tst-sscanf.c | 33 | ||||
| -rw-r--r-- | stdio-common/vfscanf.c | 12 |
4 files changed, 49 insertions, 7 deletions
diff --git a/ChangeLog b/ChangeLog index ad9df0f243..b0b9debca0 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2015-02-05 Paul Pluzhnikov <ppluzhnikov@google.com> + + [BZ #16618] + * stdio-common/tst-sscanf.c (main): Test for buffer overflow. + * stdio-common/vfscanf.c (_IO_vfscanf_internal): Compute needed + size in bytes. Store needed elements in wpmax. Use needed size + in bytes for extend_alloca. + 2014-05-26 Adhemerval Zanella <azanella@linux.vnet.ibm.com> * sysdeps/powerpc/powerpc32/power4/memset.S (memset): Replace insrdi diff --git a/NEWS b/NEWS index 1c9acf3708..754ac0a7e4 100644 --- a/NEWS +++ b/NEWS @@ -11,7 +11,8 @@ Version 2.18.1 14143, 14155, 14547, 14699, 15532, 15427, 15522, 15680, 15723, 15734, 15735, 15797, 15892, 15895, 15909, 15915, 15917, 15996, 16072, 16150, - 16414, 16430, 16431, 16617, 17048, 17137, 17187, 17325, 17625, 17630. + 16414, 16430, 16431, 16617, 16618, 17048, 17137, 17187, 17325, 17625, + 17630. * Support for powerpc64le has been added. diff --git a/stdio-common/tst-sscanf.c b/stdio-common/tst-sscanf.c index 3c34f58a63..8f73c9510b 100644 --- a/stdio-common/tst-sscanf.c +++ b/stdio-common/tst-sscanf.c @@ -230,5 +230,38 @@ main (void) } } + /* BZ #16618 + The test will segfault during SSCANF if the buffer overflow + is not fixed. The size of `s` is such that it forces the use + of malloc internally and this triggers the incorrect computation. + Thus the value for SIZE is arbitrariy high enough that malloc + is used. */ + { +#define SIZE 131072 + CHAR *s = malloc ((SIZE + 1) * sizeof (*s)); + if (s == NULL) + abort (); + for (size_t i = 0; i < SIZE; i++) + s[i] = L('0'); + s[SIZE] = L('\0'); + int i = 42; + /* Scan multi-digit zero into `i`. */ + if (SSCANF (s, L("%d"), &i) != 1) + { + printf ("FAIL: bug16618: SSCANF did not read one input item.\n"); + result = 1; + } + if (i != 0) + { + printf ("FAIL: bug16618: Value of `i` was not zero as expected.\n"); + result = 1; + } + free (s); + if (result != 1) + printf ("PASS: bug16618: Did not crash.\n"); +#undef SIZE + } + + return result; } diff --git a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c index 093c8b0c58..8980a6ec8d 100644 --- a/stdio-common/vfscanf.c +++ b/stdio-common/vfscanf.c @@ -272,9 +272,10 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr, if (__builtin_expect (wpsize == wpmax, 0)) \ { \ CHAR_T *old = wp; \ - size_t newsize = (UCHAR_MAX + 1 > 2 * wpmax \ - ? UCHAR_MAX + 1 : 2 * wpmax); \ - if (use_malloc || !__libc_use_alloca (newsize)) \ + bool fits = __glibc_likely (wpmax <= SIZE_MAX / sizeof (CHAR_T) / 2); \ + size_t wpneed = MAX (UCHAR_MAX + 1, 2 * wpmax); \ + size_t newsize = fits ? wpneed * sizeof (CHAR_T) : SIZE_MAX; \ + if (!__libc_use_alloca (newsize)) \ { \ wp = realloc (use_malloc ? wp : NULL, newsize); \ if (wp == NULL) \ @@ -286,14 +287,13 @@ _IO_vfscanf_internal (_IO_FILE *s, const char *format, _IO_va_list argptr, } \ if (! use_malloc) \ MEMCPY (wp, old, wpsize); \ - wpmax = newsize; \ + wpmax = wpneed; \ use_malloc = true; \ } \ else \ { \ size_t s = wpmax * sizeof (CHAR_T); \ - wp = (CHAR_T *) extend_alloca (wp, s, \ - newsize * sizeof (CHAR_T)); \ + wp = (CHAR_T *) extend_alloca (wp, s, newsize); \ wpmax = s / sizeof (CHAR_T); \ if (old != NULL) \ MEMCPY (wp, old, wpsize); \ |