+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.
+
2014-06-21 Allan McRae <allan@archlinux.org>
* NEWS: Mention CVE-2014-4043.
* The following bugs are resolved with this release:
6530, 14195, 14547, 14459, 14476, 14562, 14621, 14648, 14699, 14756, 14831,
- 15078, 15754, 15755, 16072, 17048, 17137, 17187, 17325.
+ 15078, 15754, 15755, 16072, 16617, 17048, 17137, 17187, 17325.
+
+* CVE-2012-3406 printf-style functions could run into a stack overflow when
+ processing format strings with a large number of format specifiers.
* CVE-2014-4043 The posix_spawn_file_actions_addopen implementation did not
copy the path argument. This allowed programs to cause posix_spawn to
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
+ bug25 bug23-2 bug23-3 bug23-4
test-srcs = tst-unbputc tst-printf
--- /dev/null
+#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"
--- /dev/null
+#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"
--- /dev/null
+#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;
+}
/* 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. */
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. */
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. */
}
all_done:
- free (args_malloced);
- free (workstart);
+ if (specs_malloced)
+ free (specs);
+ if (__glibc_unlikely (args_malloced != NULL))
+ free (args_malloced);
+ if (__glibc_unlikely (workstart != NULL))
+ free (workstart);
/* Unlock the stream. */
_IO_funlockfile (s);
_IO_cleanup_region_end (0);
projects / thirdparty / glibc.git / commitdiff
