From 3112f71d69204e618487250c400ad3bbf656d68e Mon Sep 17 00:00:00 2001 From: Sona Sarmadi Date: Wed, 21 Oct 2015 09:32:03 +0200 Subject: glibc/wscanf: CVE-2015-1472 Fixes a heap buffer overflow in glibc wscanf. References: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1472 https://sourceware.org/ml/libc-alpha/2015-02/msg00119.html http://openwall.com/lists/oss-security/2015/02/04/1 Reference to upstream fix: https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commit; h=5bd80bfe9ca0d955bfbbc002781bc7b01b6bcb06 Signed-off-by: Sona Sarmadi Signed-off-by: Tudor Florea --- ...5-1472-wscanf-allocates-too-little-memory.patch | 108 +++++++++++++++++++++ meta/recipes-core/glibc/glibc_2.20.bb | 1 + 2 files changed, 109 insertions(+) create mode 100644 meta/recipes-core/glibc/glibc/CVE-2015-1472-wscanf-allocates-too-little-memory.patch (limited to 'meta') diff --git a/meta/recipes-core/glibc/glibc/CVE-2015-1472-wscanf-allocates-too-little-memory.patch b/meta/recipes-core/glibc/glibc/CVE-2015-1472-wscanf-allocates-too-little-memory.patch new file mode 100644 index 0000000000..ab513aafb5 --- /dev/null +++ b/meta/recipes-core/glibc/glibc/CVE-2015-1472-wscanf-allocates-too-little-memory.patch @@ -0,0 +1,108 @@ +CVE-2015-1472: wscanf allocates too little memory + +BZ #16618 + +Under certain conditions wscanf can allocate too little memory for the +to-be-scanned arguments and overflow the allocated buffer. The +implementation now correctly computes the required buffer size when +using malloc. + +A regression test was added to tst-sscanf. + +Upstream-Status: Backport + +The patch is from (Paul Pluzhnikov ): +[https://sourceware.org/git/?p=glibc.git;a=patch;h=5bd80bfe9ca0d955bfbbc002781bc7b01b6bcb06] + +diff -ruN a/ChangeLog b/ChangeLog +--- a/ChangeLog 2015-09-22 10:20:14.399408389 +0200 ++++ b/ChangeLog 2015-09-22 10:33:07.374388595 +0200 +@@ -1,3 +1,12 @@ ++2015-02-05 Paul Pluzhnikov ++ ++ [BZ #16618] CVE-2015-1472 ++ * 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. ++ ++ + 2014-12-16 Florian Weimer + + [BZ #17630] +diff -ruN a/stdio-common/tst-sscanf.c b/stdio-common/tst-sscanf.c +--- a/stdio-common/tst-sscanf.c 2015-09-22 10:20:09.995596201 +0200 ++++ b/stdio-common/tst-sscanf.c 2015-09-22 10:21:39.211791399 +0200 +@@ -233,5 +233,38 @@ + } + } + ++ /* 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 -ruN a/stdio-common/vfscanf.c b/stdio-common/vfscanf.c +--- a/stdio-common/vfscanf.c 2015-09-22 10:20:14.051423230 +0200 ++++ b/stdio-common/vfscanf.c 2015-09-22 10:21:39.215791228 +0200 +@@ -279,9 +279,10 @@ + if (__glibc_unlikely (wpsize == wpmax)) \ + { \ + 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) \ +@@ -293,14 +294,13 @@ + } \ + 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); \ diff --git a/meta/recipes-core/glibc/glibc_2.20.bb b/meta/recipes-core/glibc/glibc_2.20.bb index a0736cdeec..cfbc1c2956 100644 --- a/meta/recipes-core/glibc/glibc_2.20.bb +++ b/meta/recipes-core/glibc/glibc_2.20.bb @@ -48,6 +48,7 @@ CVEPATCHES = "\ file://CVE-2014-7817-wordexp-fails-to-honour-WRDE_NOCMD.patch \ file://CVE-2012-3406-Stack-overflow-in-vfprintf-BZ-16617.patch \ file://CVE-2014-9402_endless-loop-in-getaddr_r.patch \ + file://CVE-2015-1472-wscanf-allocates-too-little-memory.patch \ " LIC_FILES_CHKSUM = "file://LICENSES;md5=e9a558e243b36d3209f380deb394b213 \ file://COPYING;md5=b234ee4d69f5fce4486a80fdaf4a4263 \ -- cgit v1.2.3-54-g00ecf