When wait_for_completion_interruptible_timeout() is called from
_request_firmware_load() with a large timeout value (here, MAX_JIFFY_OFFSET
because it's a an explicit call to the user helper), its return value (a
long) will overflow when silently casted to int, be stored as a negative
integer and then treated as an error.
This bug was introduced in commit 68ff2a00dbf5 ("firmware_loader: handle
timeout via wait_for_completion_interruptible_timeout()") when a delay work
was replaced by the call to wait_for_completion_interruptible_timeout().
Fix this by re-using the timeout variable and only set retval in specific
cases.
Signed-off-by: Yves-Alexis Perez <cor...@corsac.net>
Fixes: 68ff2a00dbf5 "firmware_loader: handle timeout via
wait_for_completion_interruptible_timeout()"
Cc: Luis R. Rodriguez <mcg...@kernel.org>
Cc: Ming Lei <ming....@canonical.com>
Cc: Bjorn Andersson <bjorn.anders...@linaro.org>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Cc: sta...@vger.kernel.org
Acked-by: Luis R. Rodriguez <mcg...@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.anders...@linaro.org>
---
Changelog:
v2: rewrite the changelog following comments by Luis
drivers/base/firmware_class.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 22d1760..a95e1e5 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -955,13 +955,14 @@ static int _request_firmware_load(struct firmware_priv
*fw_priv,
timeout = MAX_JIFFY_OFFSET;
}
- retval = wait_for_completion_interruptible_timeout(&buf->completion,
+ timeout = wait_for_completion_interruptible_timeout(&buf->completion,
timeout);
- if (retval == -ERESTARTSYS || !retval) {
+ if (timeout == -ERESTARTSYS || !timeout) {
+ retval = timeout;
mutex_lock(&fw_lock);
fw_load_abort(fw_priv);
mutex_unlock(&fw_lock);
- } else if (retval > 0) {
+ } else if (timeout > 0) {
retval = 0;
}
--
2.10.2
