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| author |   Jubin Zhong <zhongjubin@huawei.com> | 2020-12-02 10:33:42 +0800 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2020-12-04 17:38:27 -0600 |
| commit | 4684709bf81a2d98152ed6b610e3d5c403f9bced (patch) | |
| tree | 6331f788ee519abcc2614ca4e34700d2c64175c4 /drivers/pci/slot.c | |
| parent | PCI: ibmphp: Remove unneeded break (diff) | |
| download | linux-dev-4684709bf81a2d98152ed6b610e3d5c403f9bced.tar.xz linux-dev-4684709bf81a2d98152ed6b610e3d5c403f9bced.zip | |
PCI: Fix pci_slot_release() NULL pointer dereference
If kobject_init_and_add() fails, pci_slot_release() is called to delete
slot->list from parent->slots. But slot->list hasn't been initialized
yet, so we dereference a NULL pointer:
Unable to handle kernel NULL pointer dereference at virtual address
00000000
...
CPU: 10 PID: 1 Comm: swapper/0 Not tainted 4.4.240 #197
task: ffffeb398a45ef10 task.stack: ffffeb398a470000
PC is at __list_del_entry_valid+0x5c/0xb0
LR is at pci_slot_release+0x84/0xe4
...
__list_del_entry_valid+0x5c/0xb0
pci_slot_release+0x84/0xe4
kobject_put+0x184/0x1c4
pci_create_slot+0x17c/0x1b4
__pci_hp_initialize+0x68/0xa4
pciehp_probe+0x1a4/0x2fc
pcie_port_probe_service+0x58/0x84
driver_probe_device+0x320/0x470
Initialize slot->list before calling kobject_init_and_add() to avoid this.
Fixes: 8a94644b440e ("PCI: Fix pci_create_slot() reference count leak")
Link: https://lore.kernel.org/r/1606876422-117457-1-git-send-email-zhongjubin@huawei.com
Signed-off-by: Jubin Zhong <zhongjubin@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v5.9+
Diffstat (limited to 'drivers/pci/slot.c')
| -rw-r--r-- | drivers/pci/slot.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index 3861505741e6..ed2077e7470a 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -272,6 +272,9 @@ placeholder: goto err; } + INIT_LIST_HEAD(&slot->list); + list_add(&slot->list, &parent->slots); + err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL, "%s", slot_name); if (err) { @@ -279,9 +282,6 @@ placeholder: goto err; } - INIT_LIST_HEAD(&slot->list); - list_add(&slot->list, &parent->slots); - down_read(&pci_bus_sem); list_for_each_entry(dev, &parent->devices, bus_list) if (PCI_SLOT(dev->devfn) == slot_nr) |