From e654dfd38c1ecf58d8d019f3c053189413484a5b Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Thu, 18 Jul 2019 17:53:50 -0600 Subject: [PATCH] nvme: fix memory leak caused by incorrect subsystem free When freeing the subsystem after finding another match with __nvme_find_get_subsystem(), use put_device() instead of __nvme_release_subsystem() which calls kfree() directly. Per the documentation, put_device() should always be used after device_initialization() is called. Otherwise, leaks like the one below which was detected by kmemleak may occur. Once the call of __nvme_release_subsystem() is removed it no longer makes sense to keep the helper, so fold it back into nvme_release_subsystem(). unreferenced object 0xffff8883d12bfbc0 (size 16): comm "nvme", pid 2635, jiffies 4294933602 (age 739.952s) hex dump (first 16 bytes): 6e 76 6d 65 2d 73 75 62 73 79 73 32 00 88 ff ff nvme-subsys2.... backtrace: [<000000007d8fc208>] __kmalloc_track_caller+0x16d/0x2a0 [<0000000081169e5f>] kvasprintf+0xad/0x130 [<0000000025626f25>] kvasprintf_const+0x47/0x120 [<00000000fa66ad36>] kobject_set_name_vargs+0x44/0x120 [<000000004881f8b3>] dev_set_name+0x98/0xc0 [<000000007124dae3>] nvme_init_identify+0x1995/0x38e0 [<000000009315020a>] nvme_loop_configure_admin_queue+0x4fa/0x5e0 [<000000001a63e766>] nvme_loop_create_ctrl+0x489/0xf80 [<00000000a46ecc23>] nvmf_dev_write+0x1a12/0x2220 [<000000002259b3d5>] __vfs_write+0x66/0x120 [<000000002f6df81e>] vfs_write+0x154/0x490 [<000000007e8cfc19>] ksys_write+0x10a/0x240 [<00000000ff5c7b85>] __x64_sys_write+0x73/0xb0 [<00000000fee6d692>] do_syscall_64+0xaa/0x470 [<00000000997e1ede>] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: ab9e00cc72fa ("nvme: track subsystems") Signed-off-by: Logan Gunthorpe Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- drivers/nvme/host/core.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index cc09b81fc7f4..8f3fbe5ca937 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2311,15 +2311,13 @@ static void nvme_init_subnqn(struct nvme_subsystem *subsys, struct nvme_ctrl *ct memset(subsys->subnqn + off, 0, sizeof(subsys->subnqn) - off); } -static void __nvme_release_subsystem(struct nvme_subsystem *subsys) -{ - ida_simple_remove(&nvme_subsystems_ida, subsys->instance); - kfree(subsys); -} - static void nvme_release_subsystem(struct device *dev) { - __nvme_release_subsystem(container_of(dev, struct nvme_subsystem, dev)); + struct nvme_subsystem *subsys = + container_of(dev, struct nvme_subsystem, dev); + + ida_simple_remove(&nvme_subsystems_ida, subsys->instance); + kfree(subsys); } static void nvme_destroy_subsystem(struct kref *ref) @@ -2477,7 +2475,7 @@ static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id) mutex_lock(&nvme_subsystems_lock); found = __nvme_find_get_subsystem(subsys->subnqn); if (found) { - __nvme_release_subsystem(subsys); + put_device(&subsys->dev); subsys = found; if (!nvme_validate_cntlid(subsys, ctrl, id)) {