Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: PCI: host-generic: Fix NULL pointer dereference on 32-bit CAM systems On 32-bit systems the config space is too large to ioremap in one go, so pci_ecam_create() maps each bus segment separately and relies on the ->add_bus callback (pci_ecam_add_bus) to populate the per-bus mapping in cfg->winp[]. pci_ecam_map_bus() then uses that mapping as the base for every config access. The generic ECAM ops (pci_generic_ecam_ops) already provide the ->add_bus and ->remove_bus callbacks, but the CAM (legacy) ops in pci-host-generic.c do not. As a result, on a 32-bit host using "pci-host-cam-generic" the per-bus mapping is never set up and the first config read dereferences a NULL base, crashing during bus enumeration: Unable to handle kernel NULL pointer dereference at virtual address 00000800 Oops [#1] CPU: 0 PID: 1 Comm: swapper Not tainted 6.9.7+ #43 Hardware name: Digilent Nexys-Video-A7 RV32 (DT) epc : pci_generic_config_read+0x40/0xb0 ra : pci_generic_config_read+0x2c/0xb0 [<c038db9c>] pci_generic_config_read+0x40/0xb0 [<c038da04>] pci_bus_read_config_dword+0x50/0xb0 [<c0391e94>] pci_bus_generic_read_dev_vendor_id+0x3c/0x1ec [<c039245c>] pci_scan_single_device+0xa4/0x11c [<c0392570>] pci_scan_slot+0x9c/0x23c [<c039388c>] pci_scan_child_bus_extend+0x58/0x2f4 [<c0393db0>] pci_scan_root_bus_bridge+0x64/0xe8 [<c0393e54>] pci_host_probe+0x20/0xc8 [<c03bc6f4>] pci_host_common_probe+0x144/0x1e4 Fix this by giving the CAM ops the same ->add_bus/->remove_bus callbacks. Since pci_ecam_add_bus() and pci_ecam_remove_bus() are static to ecam.c, move the CAM ops definition there as pci_generic_cam_ops (mirroring pci_generic_ecam_ops) and export it for pci-host-generic.c to reference. [mani: removed timestamp from log]
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 5e52eb0290f66ba0732956dcb1e365b5ca3c5108; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before baf9b0383ff770fdff123d3a832f3a99641d96dd; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 8d08713ec83a18526d1ed1fd5f0d2b901d103a10; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 74456843f18ba7f3045974d7e8b88ab993152b8c; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 0c55707bd5d0d7670704cfd0dda933809b052f67; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before a199293f3038db8d31d47aa60f1e18272cd82354; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 0916948026f623844acd08888f7cbedbf1c48d6b; affected 8fe55ef23387ce3c7488375b1fd539420d7654bb before 008cb88edb41f3c7c8e0ed763ff9f26719830984; affected 0b5877a1aeacdbf32b3bea91326592004ec7806f; affected a037ebbe72a4f98495b193112e2b2000e5e09eb5; affected 5.12.19 before 5.13; affected 5.13.4 before 5.14 |
| Linux / Linux | affected 5.14; unaffected 0 before 5.14; unaffected 5.15.218 through 5.15.*; unaffected 6.1.185 through 6.1.*; unaffected 6.6.154 through 6.6.*; unaffected 6.12.106 through 6.12.*; unaffected 6.18.47 through 6.18.*; unaffected 7.1.11 through 7.1.*; unaffected 7.2.1 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/5e52eb0290f66ba0732956dcb1e365b5ca3c5108
- https://git.kernel.org/stable/c/baf9b0383ff770fdff123d3a832f3a99641d96dd
- https://git.kernel.org/stable/c/8d08713ec83a18526d1ed1fd5f0d2b901d103a10
- https://git.kernel.org/stable/c/74456843f18ba7f3045974d7e8b88ab993152b8c
- https://git.kernel.org/stable/c/0c55707bd5d0d7670704cfd0dda933809b052f67
- https://git.kernel.org/stable/c/a199293f3038db8d31d47aa60f1e18272cd82354
- https://git.kernel.org/stable/c/0916948026f623844acd08888f7cbedbf1c48d6b
- https://git.kernel.org/stable/c/008cb88edb41f3c7c8e0ed763ff9f26719830984