This is a note to let you know that I've just added the patch titled ata: libata-transport: fix error handling in ata_tlink_add() to the 5.15-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: ata-libata-transport-fix-error-handling-in-ata_tlink.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f50128004496455aee2e200cea9e9a3df74fd8d8 Author: Yang Yingliang <yangyingliang@xxxxxxxxxx> Date: Tue Nov 8 21:40:03 2022 +0800 ata: libata-transport: fix error handling in ata_tlink_add() [ Upstream commit cf0816f6322c5c37ee52655f928e91ecf32da103 ] In ata_tlink_add(), the return value of transport_add_device() is not checked. As a result, it causes null-ptr-deref while removing the module, because transport_remove_device() is called to remove the device that was not added. Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 CPU: 33 PID: 13850 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #12 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : device_del+0x48/0x39c lr : device_del+0x44/0x39c Call trace: device_del+0x48/0x39c attribute_container_class_device_del+0x28/0x40 transport_remove_classdev+0x60/0x7c attribute_container_device_trigger+0x118/0x120 transport_remove_device+0x20/0x30 ata_tlink_delete+0x88/0xb0 [libata] ata_tport_delete+0x2c/0x60 [libata] ata_port_detach+0x148/0x1b0 [libata] ata_pci_remove_one+0x50/0x80 [libata] ahci_remove_one+0x4c/0x8c [ahci] Fix this by checking and handling return value of transport_add_device() in ata_tlink_add(). Fixes: d9027470b886 ("[libata] Add ATA transport class") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c index 3dd3b2543086..5ee46521198d 100644 --- a/drivers/ata/libata-transport.c +++ b/drivers/ata/libata-transport.c @@ -428,7 +428,9 @@ int ata_tlink_add(struct ata_link *link) goto tlink_err; } - transport_add_device(dev); + error = transport_add_device(dev); + if (error) + goto tlink_transport_err; transport_configure_device(dev); ata_for_each_dev(ata_dev, link, ALL) { @@ -443,6 +445,7 @@ int ata_tlink_add(struct ata_link *link) ata_tdev_delete(ata_dev); } transport_remove_device(dev); + tlink_transport_err: device_del(dev); tlink_err: transport_destroy_device(dev);