This is a note to let you know that I've just added the patch titled PCI: Fix pci_register_io_range() memory leak to the 5.10-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: pci-fix-pci_register_io_range-memory-leak.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3ad32979b8e2835e11278f42a962a94f2e5934d3 Author: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Date: Tue Feb 2 11:03:32 2021 +0100 PCI: Fix pci_register_io_range() memory leak [ Upstream commit f6bda644fa3a7070621c3bf12cd657f69a42f170 ] Kmemleak reports: unreferenced object 0xc328de40 (size 64): comm "kworker/1:1", pid 21, jiffies 4294938212 (age 1484.670s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 e0 d8 fc eb 00 00 00 00 ................ 00 00 10 fe 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ad758d10>] pci_register_io_range+0x3c/0x80 [<2c7f139e>] of_pci_range_to_resource+0x48/0xc0 [<f079ecc8>] devm_of_pci_get_host_bridge_resources.constprop.0+0x2ac/0x3ac [<e999753b>] devm_of_pci_bridge_init+0x60/0x1b8 [<a895b229>] devm_pci_alloc_host_bridge+0x54/0x64 [<e451ddb0>] rcar_pcie_probe+0x2c/0x644 In case a PCI host driver's probe is deferred, the same I/O range may be allocated again, and be ignored, causing a memory leak. Fix this by (a) letting logic_pio_register_range() return -EEXIST if the passed range already exists, so pci_register_io_range() will free it, and by (b) making pci_register_io_range() not consider -EEXIST an error condition. Link: https://lore.kernel.org/r/20210202100332.829047-1-geert+renesas@xxxxxxxxx Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5c9345072510..9e971fffeb6a 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4010,6 +4010,10 @@ int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr, ret = logic_pio_register_range(range); if (ret) kfree(range); + + /* Ignore duplicates due to deferred probing */ + if (ret == -EEXIST) + ret = 0; #endif return ret; diff --git a/lib/logic_pio.c b/lib/logic_pio.c index f32fe481b492..07b4b9a1f54b 100644 --- a/lib/logic_pio.c +++ b/lib/logic_pio.c @@ -28,6 +28,8 @@ static DEFINE_MUTEX(io_range_mutex); * @new_range: pointer to the IO range to be registered. * * Returns 0 on success, the error code in case of failure. + * If the range already exists, -EEXIST will be returned, which should be + * considered a success. * * Register a new IO range node in the IO range list. */ @@ -51,6 +53,7 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range) list_for_each_entry(range, &io_range_list, list) { if (range->fwnode == new_range->fwnode) { /* range already there */ + ret = -EEXIST; goto end_register; } if (range->flags == LOGIC_PIO_CPU_MMIO &&