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| author | Rusty Russell <rusty@rustcorp.com.au> | 2009-07-31 00:03:43 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2009-07-30 08:33:43 +0200 |
| commit | 8ef562d112c82ec539775698f8b63ac5ec1bd766 (patch) | |
| tree | 4bf0997d89cb138f8d061c948dca6286ab368973 /Documentation/lguest/lguest.c | |
| parent | lguest: dereferencing freed mem in add_eventfd() (diff) | |
| download | linux-8ef562d112c82ec539775698f8b63ac5ec1bd766.tar.xz linux-8ef562d112c82ec539775698f8b63ac5ec1bd766.zip | |
lguest: fix descriptor corruption in example launcher
1d589bb16b825b3a7b4edd34d997f1f1f953033d "Add serial number support
for virtio_blk, V4a" extended 'struct virtio_blk_config' to 536 bytes.
Lguest and S/390 both use an 8 bit value for the feature length, and
this change broke them (if the code is naive).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: John Cooper <john.cooper@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'Documentation/lguest/lguest.c')
| -rw-r--r-- | Documentation/lguest/lguest.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 9ebcd6ef361b..45d7d6dcae7a 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -1105,6 +1105,9 @@ static void set_config(struct device *dev, unsigned len, const void *conf) /* Copy in the config information, and store the length. */ memcpy(device_config(dev), conf, len); dev->desc->config_len = len; + + /* Size must fit in config_len field (8 bits)! */ + assert(dev->desc->config_len == len); } /* This routine does all the creation and setup of a new device, including @@ -1515,7 +1518,8 @@ static void setup_block_file(const char *filename) add_feature(dev, VIRTIO_BLK_F_SEG_MAX); conf.seg_max = cpu_to_le32(VIRTQUEUE_NUM - 2); - set_config(dev, sizeof(conf), &conf); + /* Don't try to put whole struct: we have 8 bit limit. */ + set_config(dev, offsetof(struct virtio_blk_config, geometry), &conf); verbose("device %u: virtblock %llu sectors\n", ++devices.device_num, le64_to_cpu(conf.capacity)); |