diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | NEWS | 13 | ||||
| -rw-r--r-- | stdio-common/Makefile | 2 | ||||
| -rw-r--r-- | stdio-common/bug23-2.c | 70 | ||||
| -rw-r--r-- | stdio-common/bug23-3.c | 50 | ||||
| -rw-r--r-- | stdio-common/bug23-4.c | 31 | ||||
| -rw-r--r-- | stdio-common/vfprintf.c | 40 |
7 files changed, 207 insertions, 8 deletions
diff --git a/ChangeLog b/ChangeLog index b40f6f8953..3f90c7dbf7 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2014-12-15 Jeff Law <law@redhat.com> + + [BZ #16617] + * stdio-common/vfprintf.c (vfprintf): Allocate large specs array + on the heap. (CVE-2012-3406) + * stdio-common/bug23-2.c, stdio-common/bug23-3.c: New file. + * stdio-common/bug23-4.c: New file. Test case by Joseph Myers. + * stdio-common/Makefile (tests): Add bug23-2, bug23-3, bug23-4. + 2014-12-15 Will Newton <will.newton@linaro.org> * manual/install.texi: Bump required version of texinfo diff --git a/NEWS b/NEWS index 8b788c8195..a324c10ba6 100644 --- a/NEWS +++ b/NEWS @@ -10,11 +10,11 @@ Version 2.21 * The following bugs are resolved with this release: 6652, 10672, 12847, 12926, 13862, 14132, 14138, 14171, 14498, 15215, - 15884, 16469, 16619, 16657, 16740, 16857, 17192, 17266, 17344, 17363, - 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508, 17522, - 17555, 17570, 17571, 17572, 17573, 17574, 17581, 17582, 17583, 17584, - 17585, 17589, 17594, 17601, 17608, 17616, 17625, 17633, 17634, 17647, - 17653, 17664, 17665, 17668, 17682. + 15884, 16469, 16617, 16619, 16657, 16740, 16857, 17192, 17266, 17344, + 17363, 17370, 17371, 17411, 17460, 17475, 17485, 17501, 17506, 17508, + 17522, 17555, 17570, 17571, 17572, 17573, 17574, 17581, 17582, 17583, + 17584, 17585, 17589, 17594, 17601, 17608, 17616, 17625, 17633, 17634, + 17647, 17653, 17664, 17665, 17668, 17682. * CVE-2104-7817 The wordexp function could ignore the WRDE_NOCMD flag under certain input conditions resulting in the execution of a shell for @@ -22,6 +22,9 @@ Version 2.21 implementation now checks WRDE_NOCMD immediately before executing the shell and returns the error WRDE_CMDSUB as expected. +* CVE-2012-3406 printf-style functions could run into a stack overflow when + processing format strings with a large number of format specifiers. + * The minimum GCC version that can be used to build this version of the GNU C Library is GCC 4.6. Older GCC versions, and non-GNU compilers, can still be used to compile programs using the GNU C Library. diff --git a/stdio-common/Makefile b/stdio-common/Makefile index f76365774a..960996614e 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -57,7 +57,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \ bug19 bug19a tst-popen2 scanf13 scanf14 scanf15 bug20 bug21 bug22 \ scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \ bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \ - bug25 tst-printf-round bug26 + bug25 tst-printf-round bug23-2 bug23-3 bug23-4 test-srcs = tst-unbputc tst-printf diff --git a/stdio-common/bug23-2.c b/stdio-common/bug23-2.c new file mode 100644 index 0000000000..9e0cfe6860 --- /dev/null +++ b/stdio-common/bug23-2.c @@ -0,0 +1,70 @@ +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +static const char expected[] = "\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55\ +\n\ +a\n\ +abbcd55%%%%%%%%%%%%%%%%%%%%%%%%%%\n"; + +static int +do_test (void) +{ + char *buf = malloc (strlen (expected) + 1); + snprintf (buf, strlen (expected) + 1, + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + "%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\n", + "a", "b", "c", "d", 5); + return strcmp (buf, expected) != 0; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" diff --git a/stdio-common/bug23-3.c b/stdio-common/bug23-3.c new file mode 100644 index 0000000000..57c8cef195 --- /dev/null +++ b/stdio-common/bug23-3.c @@ -0,0 +1,50 @@ +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +int +do_test (void) +{ + size_t instances = 16384; +#define X0 "\n%1$s\n" "%1$s" "%2$s" "%2$s" "%3$s" "%4$s" "%5$d" "%5$d" + const char *item = "\na\nabbcd55"; +#define X3 X0 X0 X0 X0 X0 X0 X0 X0 +#define X6 X3 X3 X3 X3 X3 X3 X3 X3 +#define X9 X6 X6 X6 X6 X6 X6 X6 X6 +#define X12 X9 X9 X9 X9 X9 X9 X9 X9 +#define X14 X12 X12 X12 X12 +#define TRAILER "%%%%%%%%%%%%%%%%%%%%%%%%%%" +#define TRAILER2 TRAILER TRAILER + size_t length = instances * strlen (item) + strlen (TRAILER) + 1; + + char *buf = malloc (length + 1); + snprintf (buf, length + 1, + X14 TRAILER2 "\n", + "a", "b", "c", "d", 5); + + const char *p = buf; + size_t i; + for (i = 0; i < instances; ++i) + { + const char *expected; + for (expected = item; *expected; ++expected) + { + if (*p != *expected) + { + printf ("mismatch at offset %zu (%zu): expected %d, got %d\n", + (size_t) (p - buf), i, *expected & 0xFF, *p & 0xFF); + return 1; + } + ++p; + } + } + if (strcmp (p, TRAILER "\n") != 0) + { + printf ("mismatch at trailer: [%s]\n", p); + return 1; + } + free (buf); + return 0; +} +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" diff --git a/stdio-common/bug23-4.c b/stdio-common/bug23-4.c new file mode 100644 index 0000000000..a4785640de --- /dev/null +++ b/stdio-common/bug23-4.c @@ -0,0 +1,31 @@ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/resource.h> + +#define LIMIT 1000000 + +int +main (void) +{ + struct rlimit lim; + getrlimit (RLIMIT_STACK, &lim); + lim.rlim_cur = 1048576; + setrlimit (RLIMIT_STACK, &lim); + char *fmtstr = malloc (4 * LIMIT + 1); + if (fmtstr == NULL) + abort (); + char *output = malloc (LIMIT + 1); + if (output == NULL) + abort (); + for (size_t i = 0; i < LIMIT; i++) + memcpy (fmtstr + 4 * i, "%1$d", 4); + fmtstr[4 * LIMIT] = '\0'; + int ret = snprintf (output, LIMIT + 1, fmtstr, 0); + if (ret != LIMIT) + abort (); + for (size_t i = 0; i < LIMIT; i++) + if (output[i] != '0') + abort (); + return 0; +} diff --git a/stdio-common/vfprintf.c b/stdio-common/vfprintf.c index c4ff8334b2..429a3d1a83 100644 --- a/stdio-common/vfprintf.c +++ b/stdio-common/vfprintf.c @@ -263,6 +263,12 @@ vfprintf (FILE *s, const CHAR_T *format, va_list ap) /* For the argument descriptions, which may be allocated on the heap. */ void *args_malloced = NULL; + /* For positional argument handling. */ + struct printf_spec *specs; + + /* Track if we malloced the SPECS array and thus must free it. */ + bool specs_malloced = false; + /* This table maps a character into a number representing a class. In each step there is a destination label for each class. */ @@ -1679,8 +1685,8 @@ do_positional: size_t nspecs = 0; /* A more or less arbitrary start value. */ size_t nspecs_size = 32 * sizeof (struct printf_spec); - struct printf_spec *specs = alloca (nspecs_size); + specs = alloca (nspecs_size); /* The number of arguments the format string requests. This will determine the size of the array needed to store the argument attributes. */ @@ -1721,11 +1727,39 @@ do_positional: if (nspecs * sizeof (*specs) >= nspecs_size) { /* Extend the array of format specifiers. */ + if (nspecs_size * 2 < nspecs_size) + { + __set_errno (ENOMEM); + done = -1; + goto all_done; + } struct printf_spec *old = specs; - specs = extend_alloca (specs, nspecs_size, 2 * nspecs_size); + if (__libc_use_alloca (2 * nspecs_size)) + specs = extend_alloca (specs, nspecs_size, 2 * nspecs_size); + else + { + nspecs_size *= 2; + specs = malloc (nspecs_size); + if (specs == NULL) + { + __set_errno (ENOMEM); + specs = old; + done = -1; + goto all_done; + } + } /* Copy the old array's elements to the new space. */ memmove (specs, old, nspecs * sizeof (*specs)); + + /* If we had previously malloc'd space for SPECS, then + release it after the copy is complete. */ + if (specs_malloced) + free (old); + + /* Now set SPECS_MALLOCED if needed. */ + if (!__libc_use_alloca (nspecs_size)) + specs_malloced = true; } /* Parse the format specifier. */ @@ -2046,6 +2080,8 @@ do_positional: } all_done: + if (specs_malloced) + free (specs); if (__glibc_unlikely (args_malloced != NULL)) free (args_malloced); if (__glibc_unlikely (workstart != NULL)) |