qemu/block
Jim Meyering 6265eb26a3 don't dereference NULL after failed strdup
Most of these are obvious NULL-deref bug fixes, for example,
the ones in these files:

  block/curl.c
  net.c
  slirp/misc.c

and the first one in block/vvfat.c.
The others in block/vvfat.c may not lead to an immediate segfault, but I
traced the two schedule_rename(..., strdup(path)) uses, and a failed
strdup would appear to trigger this assertion in handle_renames_and_mkdirs:

	    assert(commit->path);

The conversion to use qemu_strdup in envlist_to_environ is not technically
needed, but does avoid a theoretical leak in the caller when strdup fails
for one value, but later succeeds in allocating another buffer(plausible,
if one string length is much larger than the others).  The caller does
not know the length of the returned list, and as such can only free
pointers until it hits the first NULL.  If there are non-NULL pointers
beyond the first, their buffers would be leaked.  This one is admittedly
far-fetched.

The two in linux-user/main.c are worth fixing to ensure that an
OOM error is diagnosed up front, rather than letting it provoke some
harder-to-diagnose secondary error, in case of exec failure, or worse, in
case the exec succeeds but with an invalid list of command line options.
However, considering how unlikely it is to encounter a failed strdup early
in main, this isn't a big deal.  Note that adding the required uses of
qemu_strdup here and in envlist.c induce link failures because qemu_strdup
is not currently in any library they're linked with.  So for now, I've
omitted those changes, as well as the fixes in target-i386/helper.c
and target-sparc/helper.c.

If you'd like to see the above discussion (or anything else)
in the commit log, just let me know and I'll be happy to adjust.

>From 9af42864fd1ea666bd25e2cecfdfae74c20aa8c7 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@redhat.com>
Date: Mon, 8 Feb 2010 18:29:29 +0100
Subject: [PATCH] don't dereference NULL after failed strdup

Handle failing strdup by replacing each use with qemu_strdup,
so as not to dereference NULL or trigger a failing assertion.
* block/curl.c (curl_open): s/\bstrdup\b/qemu_strdup/
* block/vvfat.c (init_directories): Likewise.
(get_cluster_count_for_direntry, check_directory_consistency): Likewise.
* net.c (parse_host_src_port): Likewise.
* slirp/misc.c (fork_exec): Likewise.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-02-10 14:00:53 -06:00
..
bochs.c Read-only device changed to opens it's file for read-only. 2010-01-26 15:42:01 -06:00
cloop.c Move block drivers into their own directory 2009-05-14 16:13:46 -05:00
cow.c block/cow.c: fix warnings with _FORTIFY_SOURCE 2010-01-26 14:59:20 -06:00
curl.c don't dereference NULL after failed strdup 2010-02-10 14:00:53 -06:00
dmg.c dmg: fix ->open failure 2010-01-11 13:41:00 -06:00
nbd.c block: kill BDRV_O_CREAT 2010-01-26 15:42:02 -06:00
parallels.c Read-only device changed to opens it's file for read-only. 2010-01-26 15:42:01 -06:00
qcow.c block/qcow.c: fix warnings with _FORTIFY_SOURCE 2010-01-26 14:59:20 -06:00
qcow2-cluster.c qcow2: Fix signedness bugs 2010-02-10 11:56:57 -06:00
qcow2-refcount.c qcow2: Don't ignore qcow2_alloc_clusters return value 2010-01-26 14:59:19 -06:00
qcow2-snapshot.c qcow2: Don't ignore qcow2_alloc_clusters return value 2010-01-26 14:59:19 -06:00
qcow2.c qcow2: rename two QCowAIOCB members 2010-01-26 15:45:00 -06:00
qcow2.h qcow2: Fix signedness bugs 2010-02-10 11:56:57 -06:00
raw-posix-aio.h Remove aio_ctx from paio_* interface 2009-10-30 08:39:34 -05:00
raw-posix.c block/raw-posix: Abort on pread beyond end of non-growable file 2010-01-26 16:41:07 -06:00
raw-win32.c block: kill BDRV_O_CREAT 2010-01-26 15:42:02 -06:00
vdi.c block/vdi: allow disk sizes not multiple of block size 2010-01-08 09:58:40 -06:00
vmdk.c block/vmdk.o: fix warnings with _FORTIFY_SOURCE 2010-01-26 14:59:20 -06:00
vpc.c Fix spelling in comment. 2009-09-09 14:57:20 -05:00
vvfat.c don't dereference NULL after failed strdup 2010-02-10 14:00:53 -06:00