nvme-tcp: validate the TLS handshake timeout

tls_handshake_timeout is writable but stored as a signed int. Multiplying
the value by MSEC_PER_SEC and HZ therefore uses signed arithmetic.

With HZ=1000, setting it to 2147484 overflows both multiplications. If
the handshake request is accepted and its completion remains pending,
schedule_timeout() reports a wrong timeout value with a stack dump and
returns zero. The handshake then fails immediately with -ETIMEDOUT,
while the handshake agent was given about 24.9 days. Negative values
such as -1 have the same kernel-side effect.

Store the parameter as an unsigned int and reject values that cannot be
represented both by tls_handshake_args::ta_timeout_ms and by a safe
jiffies delay. Take one snapshot so a concurrent parameter update cannot
give the handshake agent and completion wait different timeouts.
Document the accepted range for built-in use.

wait_for_completion_interruptible_timeout() returns the remaining
jiffies as a long after a successful completion. Keep that result in a
long because an accepted timeout can exceed INT_MAX jiffies on 64-bit
systems.

Negative and oversized values now fail with -EINVAL. Keep zero valid,
preserving the existing immediate-timeout behavior.

Fixes: be8e82caa685 ("nvme-tcp: enable TLS handshake upcall")
Cc: stable@vger.kernel.org
Reviewed-by: Hannes Reinecke <hare@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yingjie Wang <1075151112@qq.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

0 files changed, 0 insertions, 0 deletions