[PATCH 4.19 37/52] RDMA/srpt: Support specifying the srpt_service_guid parameter

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bart Van Assche <bvanassche@acm.org>

[ Upstream commit fdfa083549de5d50ebf7f6811f33757781e838c0 ]

Make loading ib_srpt with this parameter set work. The current behavior is
that setting that parameter while loading the ib_srpt kernel module
triggers the following kernel crash:

BUG: kernel NULL pointer dereference, address: 0000000000000000
Call Trace:
 <TASK>
 parse_one+0x18c/0x1d0
 parse_args+0xe1/0x230
 load_module+0x8de/0xa60
 init_module_from_file+0x8b/0xd0
 idempotent_init_module+0x181/0x240
 __x64_sys_finit_module+0x5a/0xb0
 do_syscall_64+0x5f/0xe0
 entry_SYSCALL_64_after_hwframe+0x6e/0x76

Cc: LiHonggang <honggangli@163.com>
Reported-by: LiHonggang <honggangli@163.com>
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240205004207.17031-1-bvanassche@acm.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/ulp/srpt/ib_srpt.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 6090f1ce0c56f..f3d83a05aa4fa 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -82,12 +82,16 @@ module_param(srpt_srq_size, int, 0444);
 MODULE_PARM_DESC(srpt_srq_size,
 		 "Shared receive queue (SRQ) size.");
 
+static int srpt_set_u64_x(const char *buffer, const struct kernel_param *kp)
+{
+	return kstrtou64(buffer, 16, (u64 *)kp->arg);
+}
 static int srpt_get_u64_x(char *buffer, const struct kernel_param *kp)
 {
 	return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
 }
-module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
-		  0444);
+module_param_call(srpt_service_guid, srpt_set_u64_x, srpt_get_u64_x,
+		  &srpt_service_guid, 0444);
 MODULE_PARM_DESC(srpt_service_guid,
 		 "Using this value for ioc_guid, id_ext, and cm_listen_id"
 		 " instead of using the node_guid of the first HCA.");
-- 
2.43.0