| 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-2021-47081: habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory |
| |
| Our code analyzer reported a uaf. |
| |
| In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create() |
| with 2 refcount. |
| If hl_cs_allocate_job() failed, the execution runs into release_cb |
| branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed |
| if other thread also drops one ref. Then cb is used by cb->id later, |
| which is a potential uaf. |
| |
| My patch add a variable 'id' to accept the value of cb->id before the |
| hl_cb_put(cb) is called, to avoid the potential uaf. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47081 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.12 with commit 423815bf02e257091d5337be5c63b57fc29e4254 and fixed in 5.12.7 with commit b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7 |
| Issue introduced in 5.12 with commit 423815bf02e257091d5337be5c63b57fc29e4254 and fixed in 5.13 with commit 115726c5d312b462c9d9931ea42becdfa838a076 |
| |
| 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-2021-47081 |
| 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/misc/habanalabs/gaudi/gaudi.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/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7 |
| https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076 |
