When enabling a lib32-gcc in a 64 bit build, without doing any other configuration, the mutilib dir is unspecified, which is represented internally in gcc as "." and as such uncovers an invalid free on a non-malloc'd pointer. As suggested by the gcc folks, simply make sure the "." case is also stored in a malloc'd pointer, so that the intended runtime behaviour of the code remains unchanged. Patch has been accepted by upstream maintainers of gcc. (From OE-Core rev: bf1473d0c1b099b8d919835cc430b99606134aab) Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
67 lines
2.3 KiB
Diff
67 lines
2.3 KiB
Diff
From a22a222c8f9299f6c07a0274388ade7d4ab8c28d Mon Sep 17 00:00:00 2001
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From: Paul Gortmaker <paul.gortmaker@windriver.com>
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Date: Fri, 20 Jun 2014 16:41:08 -0400
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Subject: [PATCH] gcc: fix segfault from calling free on non-malloc'd area
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We see the following on a 32bit gcc installed on 64 bit host:
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Reading symbols from ./i586-pokymllib32-linux-gcc...done.
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(gdb) run
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Starting program: x86-pokymllib32-linux/lib32-gcc/4.9.0-r0/image/usr/bin/i586-pokymllib32-linux-gcc
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Program received signal SIGSEGV, Segmentation fault.
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0xf7e957e0 in free () from /lib/i386-linux-gnu/libc.so.6
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(gdb) bt
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#0 0xf7e957e0 in free () from /lib/i386-linux-gnu/libc.so.6
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#1 0x0804b73c in set_multilib_dir () at gcc-4.9.0/gcc/gcc.c:7827
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#2 main (argc=1, argv=0xffffd504) at gcc-4.9.0/gcc/gcc.c:6688
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(gdb)
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The problem arises because we conditionally assign the pointer we
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eventually free, and the conditional may assign the pointer to the
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non-malloc'd internal string "." which fails when we free it here:
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if (multilib_dir == NULL && multilib_os_dir != NULL
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&& strcmp (multilib_os_dir, ".") == 0)
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{
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free (CONST_CAST (char *, multilib_os_dir));
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...
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As suggested by Jakub, ensure the "." case is also malloc'd via
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xstrdup() and hence the pointer for the "." case can be freed.
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Cc: Jakub Jelinek <jakub@redhat.com>
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Cc: Jeff Law <law@redhat.com>
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Cc: Matthias Klose <doko@ubuntu.com>
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CC: Tobias Burnus <burnus@net-b.de>
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Upstream-Status: Accepted [ https://gcc.gnu.org/ml/gcc-patches/2014-06/msg02069.html ]
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Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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diff --git a/gcc/gcc.c b/gcc/gcc.c
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index 9ac18e60d801..168acf7eb0c9 100644
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--- a/gcc/gcc.c
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+++ b/gcc/gcc.c
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@@ -7790,10 +7790,15 @@ set_multilib_dir (void)
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q2++;
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if (*q2 == ':')
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ml_end = q2;
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- new_multilib_os_dir = XNEWVEC (char, ml_end - q);
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- memcpy (new_multilib_os_dir, q + 1, ml_end - q - 1);
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- new_multilib_os_dir[ml_end - q - 1] = '\0';
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- multilib_os_dir = *new_multilib_os_dir ? new_multilib_os_dir : ".";
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+ if (ml_end - q == 1)
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+ multilib_os_dir = xstrdup (".");
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+ else
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+ {
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+ new_multilib_os_dir = XNEWVEC (char, ml_end - q);
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+ memcpy (new_multilib_os_dir, q + 1, ml_end - q - 1);
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+ new_multilib_os_dir[ml_end - q - 1] = '\0';
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+ multilib_os_dir = new_multilib_os_dir;
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+ }
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if (q2 < end && *q2 == ':')
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{
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--
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1.9.2
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