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author | Paolo Bonzini <pbonzini@redhat.com> | 2012-04-12 14:01:03 +0200 |
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committer | Kevin Wolf <kwolf@redhat.com> | 2012-05-10 10:32:11 +0200 |
commit | 63090dac3a7c5fe02b4285cf2e5fb7017d2c7b0e (patch) | |
tree | b81ebbe1d44f8e7f19d843faa765ab38f13c1b19 /block.c | |
parent | 469ef350e1a8b5715e620dbf6f6115628e5b566e (diff) | |
download | qemu-63090dac3a7c5fe02b4285cf2e5fb7017d2c7b0e.zip qemu-63090dac3a7c5fe02b4285cf2e5fb7017d2c7b0e.tar.gz qemu-63090dac3a7c5fe02b4285cf2e5fb7017d2c7b0e.tar.bz2 |
block: open backing file as read-only when probing for size
bdrv_img_create will temporarily open the backing file to probe its size.
However, this could be done with a read-write open if the wrong flags are
passed to bdrv_img_create. Since there is really no documentation on
what flags can be passed, assume that bdrv_img_create receives the flags
with which the new image will be opened; sanitize them when opening
the backing file.
Reported-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 7 |
1 files changed, 6 insertions, 1 deletions
@@ -4103,10 +4103,15 @@ int bdrv_img_create(const char *filename, const char *fmt, if (backing_file && backing_file->value.s) { uint64_t size; char buf[32]; + int back_flags; + + /* backing files always opened read-only */ + back_flags = + flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); bs = bdrv_new(""); - ret = bdrv_open(bs, backing_file->value.s, flags, backing_drv); + ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv); if (ret < 0) { error_report("Could not open '%s'", backing_file->value.s); goto out; |