| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47005: PCI: endpoint: Fix NULL pointer dereference for ->get_features() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| PCI: endpoint: Fix NULL pointer dereference for ->get_features() |
| |
| get_features ops of pci_epc_ops may return NULL, causing NULL pointer |
| dereference in pci_epf_test_alloc_space function. Let us add a check for |
| pci_epc_feature pointer in pci_epf_test_bind before we access it to avoid |
| any such NULL pointer dereference and return -ENOTSUPP in case |
| pci_epc_feature is not found. |
| |
| When the patch is not applied and EPC features is not implemented in the |
| platform driver, we see the following dump due to kernel NULL pointer |
| dereference. |
| |
| Call trace: |
| pci_epf_test_bind+0xf4/0x388 |
| pci_epf_bind+0x3c/0x80 |
| pci_epc_epf_link+0xa8/0xcc |
| configfs_symlink+0x1a4/0x48c |
| vfs_symlink+0x104/0x184 |
| do_symlinkat+0x80/0xd4 |
| __arm64_sys_symlinkat+0x1c/0x24 |
| el0_svc_common.constprop.3+0xb8/0x170 |
| el0_svc_handler+0x70/0x88 |
| el0_svc+0x8/0x640 |
| Code: d2800581 b9403ab9 f9404ebb 8b394f60 (f9400400) |
| ---[ end trace a438e3c5a24f9df0 ]--- |
| |
| The Linux kernel CVE team has assigned CVE-2021-47005 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.1 with commit 2c04c5b8eef797dca99699cfb55ff42dd3c12c23 and fixed in 5.10.38 with commit bbed83d7060e07a5d309104d25a00f0a24441428 |
| Issue introduced in 5.1 with commit 2c04c5b8eef797dca99699cfb55ff42dd3c12c23 and fixed in 5.11.22 with commit 679ebad058b8168f10e63876d63b0877fd2fe784 |
| Issue introduced in 5.1 with commit 2c04c5b8eef797dca99699cfb55ff42dd3c12c23 and fixed in 5.12.5 with commit 0169d4f0bee44fdfef908c13ed21fcb326c38695 |
| Issue introduced in 5.1 with commit 2c04c5b8eef797dca99699cfb55ff42dd3c12c23 and fixed in 5.13 with commit 6613bc2301ba291a1c5a90e1dc24cf3edf223c03 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47005 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/pci/endpoint/functions/pci-epf-test.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/bbed83d7060e07a5d309104d25a00f0a24441428 |
| https://git.kernel.org/stable/c/679ebad058b8168f10e63876d63b0877fd2fe784 |
| https://git.kernel.org/stable/c/0169d4f0bee44fdfef908c13ed21fcb326c38695 |
| https://git.kernel.org/stable/c/6613bc2301ba291a1c5a90e1dc24cf3edf223c03 |
