From: Tim Sell <[email protected]>
visorchannel_write() and it's user visorbus_write_channel() are
exported, so all visorbus function drivers (i.e., drivers that call
visorbus_register_visor_driver()) are potentially affected by the bug.
Because of pointer-arithmetic rules, the address being written to in the
affected code was actually at byte offset:
sizeof(struct channel_header) * offset
instead of just <offset> bytes as intended.
The bug could cause some very difficult-to-diagnose symptoms. The
particular problem that led me on this chase was a kernel fault that
would occur during 'insmod visornic' after a previous 'rmmod visornic',
where we would fault during netdev_register_kobject() within
pm_runtime_set_memalloc_noio() while traversing a device list, which
occurred because dev->parent for the visorbus device had become
corrupted.
Fixes: 0abb60c1c ('staging: unisys: visorchannel_write(): Handle...')
Signed-off-by: Tim Sell <[email protected]>
Acked-by: Don Zickus <[email protected]>
Signed-off-by: Benjamin Romer <[email protected]>
---
drivers/staging/unisys/visorbus/visorchannel.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/unisys/visorbus/visorchannel.c
b/drivers/staging/unisys/visorbus/visorchannel.c
index 20b6349..af349c8 100644
--- a/drivers/staging/unisys/visorbus/visorchannel.c
+++ b/drivers/staging/unisys/visorbus/visorchannel.c
@@ -259,7 +259,8 @@ visorchannel_write(struct visorchannel *channel, ulong
offset,
if (offset < chdr_size) {
copy_size = min(chdr_size - offset, nbytes);
- memcpy(&channel->chan_hdr + offset, local, copy_size);
+ memcpy(((char *)(&channel->chan_hdr)) + offset,
+ local, copy_size);
}
memcpy_toio(channel->mapped + offset, local, nbytes);
--
2.1.4
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