When submitting a command for userspace, input and output payload bounce
buffers are allocated. For a given command, both input and output
buffers may exist and so when allocation of the input buffer fails, the
output buffer must be freed too.
As far as I can tell, userspace can't easily exploit the leak to OOM a
machine unless the machine was already near OOM state.
Fixes: 583fa5e71cae ("cxl/mem: Add basic IOCTL interface")
Reported-by: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Ben Widawsky <[email protected]>
---
drivers/cxl/mem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index df895bcca63a..244cb7d89678 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -514,8 +514,10 @@ static int handle_mailbox_cmd_from_user(struct cxl_mem
*cxlm,
if (cmd->info.size_in) {
mbox_cmd.payload_in = vmemdup_user(u64_to_user_ptr(in_payload),
cmd->info.size_in);
- if (IS_ERR(mbox_cmd.payload_in))
+ if (IS_ERR(mbox_cmd.payload_in)) {
+ kvfree(mbox_cmd.payload_out);
return PTR_ERR(mbox_cmd.payload_in);
+ }
}
rc = cxl_mem_mbox_get(cxlm);
--
2.30.1
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