| 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-2021-47124: io_uring: fix link timeout refs |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| io_uring: fix link timeout refs |
| |
| WARNING: CPU: 0 PID: 10242 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 |
| RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 |
| Call Trace: |
| __refcount_sub_and_test include/linux/refcount.h:283 [inline] |
| __refcount_dec_and_test include/linux/refcount.h:315 [inline] |
| refcount_dec_and_test include/linux/refcount.h:333 [inline] |
| io_put_req fs/io_uring.c:2140 [inline] |
| io_queue_linked_timeout fs/io_uring.c:6300 [inline] |
| __io_queue_sqe+0xbef/0xec0 fs/io_uring.c:6354 |
| io_submit_sqe fs/io_uring.c:6534 [inline] |
| io_submit_sqes+0x2bbd/0x7c50 fs/io_uring.c:6660 |
| __do_sys_io_uring_enter fs/io_uring.c:9240 [inline] |
| __se_sys_io_uring_enter+0x256/0x1d60 fs/io_uring.c:9182 |
| |
| io_link_timeout_fn() should put only one reference of the linked timeout |
| request, however in case of racing with the master request's completion |
| first io_req_complete() puts one and then io_put_req_deferred() is |
| called. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47124 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10.26 with commit 1c20e9040f49687ba2ccc2ffd4411351a6c2ebff and fixed in 5.10.43 with commit 0b2a990e5d2f76d020cb840c456e6ec5f0c27530 |
| Issue introduced in 5.10.26 with commit 1c20e9040f49687ba2ccc2ffd4411351a6c2ebff and fixed in 5.10.55 with commit 6f5d7a45f58d3abe3a936de1441b8d6318f978ff |
| Issue introduced in 5.12 with commit 9ae1f8dd372e0e4c020b345cf9e09f519265e981 and fixed in 5.12.10 with commit 876808dba2ff7509bdd7f230c4f374a0caf4f410 |
| Issue introduced in 5.12 with commit 9ae1f8dd372e0e4c020b345cf9e09f519265e981 and fixed in 5.12.19 with commit ff4a96ba5c8f9b266706280ff8021d2ef3f17e86 |
| Issue introduced in 5.12 with commit 9ae1f8dd372e0e4c020b345cf9e09f519265e981 and fixed in 5.13 with commit a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 |
| Issue introduced in 5.11.6 with commit 567c81912cec641db75ac6cb64c63f8367c97d19 |
| |
| 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-2021-47124 |
| 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: |
| fs/io_uring.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/0b2a990e5d2f76d020cb840c456e6ec5f0c27530 |
| https://git.kernel.org/stable/c/6f5d7a45f58d3abe3a936de1441b8d6318f978ff |
| https://git.kernel.org/stable/c/876808dba2ff7509bdd7f230c4f374a0caf4f410 |
| https://git.kernel.org/stable/c/ff4a96ba5c8f9b266706280ff8021d2ef3f17e86 |
| https://git.kernel.org/stable/c/a298232ee6b9a1d5d732aa497ff8be0d45b5bd82 |
