commit | 7e24eddac7f102d1cee2bba0ca8c939afda7288d | [log] [tgz] |
---|---|---|
author | Dan Williams <[email protected]> | Thu May 30 18:04:35 2024 -0700 |
committer | Arnav Kansal <[email protected]> | Thu Oct 03 00:17:09 2024 +0000 |
tree | 2c25b2132325c3f6a90502602b7b248854e7422b | |
parent | 23e832f04b41d047cd19f1397363e06f704f3635 [diff] |
PCI: Add missing bridge lock to pci_bus_lock() [ Upstream commit a4e772898f8bf2e7e1cf661a12c60a5612c4afab ] One of the true positives that the cfg_access_lock lockdep effort identified is this sequence: WARNING: CPU: 14 PID: 1 at drivers/pci/pci.c:4886 pci_bridge_secondary_bus_reset+0x5d/0x70 RIP: 0010:pci_bridge_secondary_bus_reset+0x5d/0x70 Call Trace: <TASK> ? __warn+0x8c/0x190 ? pci_bridge_secondary_bus_reset+0x5d/0x70 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? pci_bridge_secondary_bus_reset+0x5d/0x70 pci_reset_bus+0x1d8/0x270 vmd_probe+0x778/0xa10 pci_device_probe+0x95/0x120 Where pci_reset_bus() users are triggering unlocked secondary bus resets. Ironically pci_bus_reset(), several calls down from pci_reset_bus(), uses pci_bus_lock() before issuing the reset which locks everything *but* the bridge itself. For the same motivation as adding: bridge = pci_upstream_bridge(dev); if (bridge) pci_dev_lock(bridge); to pci_reset_function() for the "bus" and "cxl_bus" reset cases, add pci_dev_lock() for @bus->self to pci_bus_lock(). BUG=b/370702700 TEST=presubmit RELEASE_NOTE=Fixed CVE-2024-46750 in the Linux kernel. cos-patch: security-moderate Link: https://lore.kernel.org/r/171711747501.1628941.15217746952476635316.stgit@dwillia2-xfh.jf.intel.com Reported-by: Imre Deak <[email protected]> Closes: http://lore.kernel.org/r/[email protected] Change-Id: I03b30d0fd70f2b4f30e5eff12d4ae28b9fe26c0a Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Keith Busch <[email protected]> [bhelgaas: squash in recursive locking deadlock fix from Keith Busch: https: //lore.kernel.org/r/[email protected]] Signed-off-by: Bjorn Helgaas <[email protected]> Tested-by: Hans de Goede <[email protected]> Tested-by: Kalle Valo <[email protected]> Reviewed-by: Dave Jiang <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Kernel CVE Triage Automation <[email protected]> Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/82522 Reviewed-by: Oleksandr Tymoshenko <[email protected]> Reviewed-by: Arnav Kansal <[email protected]> Tested-by: Cusky Presubmit Bot <[email protected]>