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| author | Stan Shebs <stanshebs@google.com> | 2015-03-13 15:29:01 -0700 |
|---|---|---|
| committer | Stan Shebs <stanshebs@google.com> | 2015-03-13 15:29:01 -0700 |
| commit | 2963bd873faf3eb3be33cca3a2ef3401ec088962 (patch) | |
| tree | 4ac36cad40fdf8452d90b0ef2a61473f8b05f519 | |
| parent | d37331c9efa8e1719f8fb6a6a62bfa45901519e0 (diff) | |
| download | glibc-2963bd873faf3eb3be33cca3a2ef3401ec088962.tar.gz glibc-2963bd873faf3eb3be33cca3a2ef3401ec088962.tar.xz glibc-2963bd873faf3eb3be33cca3a2ef3401ec088962.zip | |
Backport fix for wscanf Tested:
| -rw-r--r-- | README.google | 5 | ||||
| -rw-r--r-- | stdio-common/tst-sscanf.c | 33 | ||||
| -rw-r--r-- | stdio-common/vfscanf.c | 12 |
3 files changed, 44 insertions, 6 deletions
diff --git a/README.google b/README.google index d9d6760aef..b35bb815a5 100644 --- a/README.google +++ b/README.google @@ -424,3 +424,8 @@ resolv/res_libc.c resolv/nss_dns/dns-resolve.c For b/18752432, backport infinite loop fix in getnetbyname (PR17630) https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=11e3417af6e354f1942c68a271ae51e892b2814d + +stdio-common/tst-sscanf.c +stdio-common/vfscanf.c + For b/19289207, backport memory allocation fix for wscanf (PR16618) + https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=5bd80bfe9ca0d955bfbbc002781bc7b01b6bcb06 diff --git a/stdio-common/tst-sscanf.c b/stdio-common/tst-sscanf.c index 1214c7d068..c62bee6a68 100644 --- a/stdio-common/tst-sscanf.c +++ b/stdio-common/tst-sscanf.c @@ -232,5 +232,38 @@ 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 2e1e91af78..d7a18e3ab3 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); \ |