| 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-2021-46959: spi: Fix use-after-free with devm_spi_alloc_* |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| spi: Fix use-after-free with devm_spi_alloc_* |
| |
| We can't rely on the contents of the devres list during |
| spi_unregister_controller(), as the list is already torn down at the |
| time we perform devres_find() for devm_spi_release_controller. This |
| causes devices registered with devm_spi_alloc_{master,slave}() to be |
| mistakenly identified as legacy, non-devm managed devices and have their |
| reference counters decremented below 0. |
| |
| ------------[ cut here ]------------ |
| WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174 |
| [<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98) |
| [<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24) |
| r4:b6700140 |
| [<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40) |
| [<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4) |
| r5:b6700180 r4:b6700100 |
| [<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60) |
| r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10 |
| [<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec) |
| r5:b117ad94 r4:b163dc10 |
| [<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0) |
| r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10 |
| [<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8) |
| |
| Instead, determine the devm allocation state as a flag on the |
| controller which is guaranteed to be stable during cleanup. |
| |
| The Linux kernel CVE team has assigned CVE-2021-46959 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.4.248 with commit a4add022c1552b0d51a0b89a4781919d6ebac4f9 and fixed in 4.4.271 with commit 62bb2c7f2411a0045c24831f11ecacfc35610815 |
| Issue introduced in 4.9.248 with commit 0870525cf94bc27907e94ce99afb6d7239ffd2f5 and fixed in 4.9.271 with commit 8bf96425c90f5c1dcf3b7b9df568019a1d4b8a0e |
| Issue introduced in 4.14.212 with commit 8c45a1c6c951bbe7f95db78fcab46f7337364468 and fixed in 4.14.233 with commit 8e029707f50a82c53172359c686b2536ab54e58c |
| Issue introduced in 4.19.163 with commit 234b432c7b6184b2d6c5ba2c55f0dd5023c0edf0 and fixed in 4.19.191 with commit 28a5529068c51cdf0295ab1e11a99a3a909a03e4 |
| Issue introduced in 5.4.80 with commit 3e04a4976addbedcad326f47b0dd4efc570a1fac and fixed in 5.4.119 with commit 001c8e83646ad3b847b18f6ac55a54367d917d74 |
| Issue introduced in 5.10 with commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 and fixed in 5.10.37 with commit c7fabe372a9031acd00498bc718ce27c253abfd1 |
| Issue introduced in 5.10 with commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 and fixed in 5.11.21 with commit cee78aa24578edac8cf00513dca618c0acc17cd7 |
| Issue introduced in 5.10 with commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 and fixed in 5.12.4 with commit 8735248ebb918d25427965f0db07939ed0473ec6 |
| Issue introduced in 5.10 with commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 and fixed in 5.13 with commit 794aaf01444d4e765e2b067cba01cc69c1c68ed9 |
| Issue introduced in 5.9.11 with commit bd1a5b2307279029faaddbecf2f2ac25eaef8dc6 |
| |
| 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-2021-46959 |
| 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/spi/spi.c |
| include/linux/spi/spi.h |
| |
| |
| 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/62bb2c7f2411a0045c24831f11ecacfc35610815 |
| https://git.kernel.org/stable/c/8bf96425c90f5c1dcf3b7b9df568019a1d4b8a0e |
| https://git.kernel.org/stable/c/8e029707f50a82c53172359c686b2536ab54e58c |
| https://git.kernel.org/stable/c/28a5529068c51cdf0295ab1e11a99a3a909a03e4 |
| https://git.kernel.org/stable/c/001c8e83646ad3b847b18f6ac55a54367d917d74 |
| https://git.kernel.org/stable/c/c7fabe372a9031acd00498bc718ce27c253abfd1 |
| https://git.kernel.org/stable/c/cee78aa24578edac8cf00513dca618c0acc17cd7 |
| https://git.kernel.org/stable/c/8735248ebb918d25427965f0db07939ed0473ec6 |
| https://git.kernel.org/stable/c/794aaf01444d4e765e2b067cba01cc69c1c68ed9 |
