This is a note to let you know that I've just added the patch titled netdevsim: fix memory leak in nsim_bus_dev_new() to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netdevsim-fix-memory-leak-in-nsim_bus_dev_new.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f6d0c63df5c1643b55eb92470944d86bb203dabe Author: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> Date: Wed Oct 26 09:54:05 2022 +0800 netdevsim: fix memory leak in nsim_bus_dev_new() [ Upstream commit cf2010aa1c739bab067cbc90b690d28eaa0b47da ] If device_register() failed in nsim_bus_dev_new(), the value of reference in nsim_bus_dev->dev is 1. obj->name in nsim_bus_dev->dev will not be released. unreferenced object 0xffff88810352c480 (size 16): comm "echo", pid 5691, jiffies 4294945921 (age 133.270s) hex dump (first 16 bytes): 6e 65 74 64 65 76 73 69 6d 31 00 00 00 00 00 00 netdevsim1...... backtrace: [<000000005e2e5e26>] __kmalloc_node_track_caller+0x3a/0xb0 [<0000000094ca4fc8>] kvasprintf+0xc3/0x160 [<00000000aad09bcc>] kvasprintf_const+0x55/0x180 [<000000009bac868d>] kobject_set_name_vargs+0x56/0x150 [<000000007c1a5d70>] dev_set_name+0xbb/0xf0 [<00000000ad0d126b>] device_add+0x1f8/0x1cb0 [<00000000c222ae24>] new_device_store+0x3b6/0x5e0 [<0000000043593421>] bus_attr_store+0x72/0xa0 [<00000000cbb1833a>] sysfs_kf_write+0x106/0x160 [<00000000d0dedb8a>] kernfs_fop_write_iter+0x3a8/0x5a0 [<00000000770b66e2>] vfs_write+0x8f0/0xc80 [<0000000078bb39be>] ksys_write+0x106/0x210 [<00000000005e55a4>] do_syscall_64+0x35/0x80 [<00000000eaa40bbc>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: 40e4fe4ce115 ("netdevsim: move device registration and related code to bus.c") Signed-off-by: Zhengchao Shao <shaozhengchao@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221026015405.128795-1-shaozhengchao@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c index b5f4df1a07a3..0052968e881e 100644 --- a/drivers/net/netdevsim/bus.c +++ b/drivers/net/netdevsim/bus.c @@ -117,6 +117,10 @@ static const struct attribute_group *nsim_bus_dev_attr_groups[] = { static void nsim_bus_dev_release(struct device *dev) { + struct nsim_bus_dev *nsim_bus_dev; + + nsim_bus_dev = container_of(dev, struct nsim_bus_dev, dev); + kfree(nsim_bus_dev); } static struct device_type nsim_bus_dev_type = { @@ -291,6 +295,8 @@ nsim_bus_dev_new(unsigned int id, unsigned int port_count, unsigned int num_queu err_nsim_bus_dev_id_free: ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id); + put_device(&nsim_bus_dev->dev); + nsim_bus_dev = NULL; err_nsim_bus_dev_free: kfree(nsim_bus_dev); return ERR_PTR(err); @@ -300,9 +306,8 @@ static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev) { /* Disallow using nsim_bus_dev */ smp_store_release(&nsim_bus_dev->init, false); - device_unregister(&nsim_bus_dev->dev); ida_free(&nsim_bus_dev_ids, nsim_bus_dev->dev.id); - kfree(nsim_bus_dev); + device_unregister(&nsim_bus_dev->dev); } static struct device_driver nsim_driver = {