[PATCH] nvme-fabrics: error out to unlock the mutex

[Chaitanya Kulkarni]

Currently, in the nvmf_host_add() function, if the nvmf_host_alloc()
call failed to allocate memory for the host, the code would directly
return -ENOMEM without unlocking the nvmf_hosts_mutex. This could
lead to potential issues with mutex synchronization.

Fix that error handling mechanism by jumping to the out_unlock label
when nvmf_host_alloc() fails. This ensures that the mutex is unlocked
before returning the error code. The updated code enhances avoids
possible deadlocks.

Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Julia Lawall <julia.lawall at inria.fr>
Closes: https://lore.kernel.org/r/202306020909.MTUEBeIa-lkp@intel.com/
Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
---
 drivers/nvme/host/fabrics.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index b1fa27b60917..c4345d1d98aa 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -92,8 +92,10 @@ static struct nvmf_host *nvmf_host_add(const char *hostnqn, uuid_t *id)
 	}
 
 	host = nvmf_host_alloc(hostnqn, id);
-	if (!host)
-		return ERR_PTR(-ENOMEM);
+	if (!host) {
+		host = ERR_PTR(-ENOMEM);
+		goto out_unlock;
+	}
 
 	list_add_tail(&host->list, &nvmf_hosts);
 out_unlock:
-- 
2.40.0