From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Bjorn Helgaas <bhelgaas@google.com>,
John Garry <john.garry@huawei.com>, Arnd Bergmann <arnd@arndb.de>
Cc: linux-pci@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-kernel@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] PCI: Fix memory leak in pci_register_io_range()
Date: Tue, 2 Feb 2021 11:03:32 +0100 [thread overview]
Message-ID: <20210202100332.829047-1-geert+renesas@glider.be> (raw)
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.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/pci/pci.c | 4 ++++
lib/logic_pio.c | 3 +++
2 files changed, 7 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 09b03cfba8894955..c651003e304a2b71 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4037,6 +4037,10 @@ 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 f32fe481b4922bc1..07b4b9a1f54b6bf5 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 &&
--
2.25.1
next reply other threads:[~2021-02-02 10:05 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 10:03 Geert Uytterhoeven [this message]
2021-02-17 23:32 ` [PATCH] PCI: Fix memory leak in pci_register_io_range() Bjorn Helgaas
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