| 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-2021-47292: io_uring: fix memleak in io_init_wq_offload() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| io_uring: fix memleak in io_init_wq_offload() |
| |
| I got memory leak report when doing fuzz test: |
| |
| BUG: memory leak |
| unreferenced object 0xffff888107310a80 (size 96): |
| comm "syz-executor.6", pid 4610, jiffies 4295140240 (age 20.135s) |
| hex dump (first 32 bytes): |
| 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ |
| 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... |
| backtrace: |
| [<000000001974933b>] kmalloc include/linux/slab.h:591 [inline] |
| [<000000001974933b>] kzalloc include/linux/slab.h:721 [inline] |
| [<000000001974933b>] io_init_wq_offload fs/io_uring.c:7920 [inline] |
| [<000000001974933b>] io_uring_alloc_task_context+0x466/0x640 fs/io_uring.c:7955 |
| [<0000000039d0800d>] __io_uring_add_tctx_node+0x256/0x360 fs/io_uring.c:9016 |
| [<000000008482e78c>] io_uring_add_tctx_node fs/io_uring.c:9052 [inline] |
| [<000000008482e78c>] __do_sys_io_uring_enter fs/io_uring.c:9354 [inline] |
| [<000000008482e78c>] __se_sys_io_uring_enter fs/io_uring.c:9301 [inline] |
| [<000000008482e78c>] __x64_sys_io_uring_enter+0xabc/0xc20 fs/io_uring.c:9301 |
| [<00000000b875f18f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] |
| [<00000000b875f18f>] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 |
| [<000000006b0a8484>] entry_SYSCALL_64_after_hwframe+0x44/0xae |
| |
| CPU0 CPU1 |
| io_uring_enter io_uring_enter |
| io_uring_add_tctx_node io_uring_add_tctx_node |
| __io_uring_add_tctx_node __io_uring_add_tctx_node |
| io_uring_alloc_task_context io_uring_alloc_task_context |
| io_init_wq_offload io_init_wq_offload |
| hash = kzalloc hash = kzalloc |
| ctx->hash_map = hash ctx->hash_map = hash <- one of the hash is leaked |
| |
| When calling io_uring_enter() in parallel, the 'hash_map' will be leaked, |
| add uring_lock to protect 'hash_map'. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47292 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.12 with commit e941894eae31b52f0fd9bdb3ce20620afa152f45 and fixed in 5.13.6 with commit 502731a03f27cba1513fbbff77e508185ffce5bb |
| Issue introduced in 5.12 with commit e941894eae31b52f0fd9bdb3ce20620afa152f45 and fixed in 5.14 with commit 362a9e65289284f36403058eea2462d0330c1f24 |
| |
| 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-2021-47292 |
| 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/502731a03f27cba1513fbbff77e508185ffce5bb |
| https://git.kernel.org/stable/c/362a9e65289284f36403058eea2462d0330c1f24 |
