| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49902: block: Fix possible memory leak for rq_wb on add_disk failure |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| block: Fix possible memory leak for rq_wb on add_disk failure |
| |
| kmemleak reported memory leaks in device_add_disk(): |
| |
| kmemleak: 3 new suspected memory leaks |
| |
| unreferenced object 0xffff88800f420800 (size 512): |
| comm "modprobe", pid 4275, jiffies 4295639067 (age 223.512s) |
| hex dump (first 32 bytes): |
| 04 00 00 00 08 00 00 00 01 00 00 00 00 00 00 00 ................ |
| 00 e1 f5 05 00 00 00 00 00 00 00 00 00 00 00 00 ................ |
| backtrace: |
| [<00000000d3662699>] kmalloc_trace+0x26/0x60 |
| [<00000000edc7aadc>] wbt_init+0x50/0x6f0 |
| [<0000000069601d16>] wbt_enable_default+0x157/0x1c0 |
| [<0000000028fc393f>] blk_register_queue+0x2a4/0x420 |
| [<000000007345a042>] device_add_disk+0x6fd/0xe40 |
| [<0000000060e6aab0>] nbd_dev_add+0x828/0xbf0 [nbd] |
| ... |
| |
| It is because the memory allocated in wbt_enable_default() is not |
| released in device_add_disk() error path. |
| Normally, these memory are freed in: |
| |
| del_gendisk() |
| rq_qos_exit() |
| rqos->ops->exit(rqos); |
| wbt_exit() |
| |
| So rq_qos_exit() is called to free the rq_wb memory for wbt_init(). |
| However in the error path of device_add_disk(), only |
| blk_unregister_queue() is called and make rq_wb memory leaked. |
| |
| Add rq_qos_exit() to the error path to fix it. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49902 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 5.15.78 with commit 4e68c5da60cd79950bd56287ae80b39d6261f995 |
| Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 6.0.8 with commit 528677d3b4af985445bd4ac667485ded1ed11220 |
| Issue introduced in 5.15 with commit 83cbce9574462c6b4eed6797bdaf18fae6859ab3 and fixed in 6.1 with commit fa81cbafbf5764ad5053512152345fab37a1fe18 |
| |
| 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-2022-49902 |
| 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: |
| block/genhd.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/4e68c5da60cd79950bd56287ae80b39d6261f995 |
| https://git.kernel.org/stable/c/528677d3b4af985445bd4ac667485ded1ed11220 |
| https://git.kernel.org/stable/c/fa81cbafbf5764ad5053512152345fab37a1fe18 |
