ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock 漏洞信息(CVE-2022-49272)

一、漏洞 CVE-2022-49272 基础信息

AIGC 神龙大模型
美国国家漏洞数据库 NVD

漏洞标题

ALSA: pcm: 修复与 buffer_mutex 和 mmap_lock 的潜在 AB/BA 锁定问题

来源：AIGC 神龙大模型

漏洞描述信息

N/A

来源：AIGC 神龙大模型

CVSS信息

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

来源：AIGC 神龙大模型

漏洞类别

加锁机制不恰当

来源：AIGC 神龙大模型

漏洞标题

ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock

来源：美国国家漏洞数据库 NVD

漏洞描述信息

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock syzbot caught a potential deadlock between the PCM runtime->buffer_mutex and the mm->mmap_lock. It was brought by the recent fix to cover the racy read/write and other ioctls, and in that commit, I overlooked a (hopefully only) corner case that may take the revert lock, namely, the OSS mmap. The OSS mmap operation exceptionally allows to re-configure the parameters inside the OSS mmap syscall, where mm->mmap_mutex is already held. Meanwhile, the copy_from/to_user calls at read/write operations also take the mm->mmap_lock internally, hence it may lead to a AB/BA deadlock. A similar problem was already seen in the past and we fixed it with a refcount (in commit b248371628aa). The former fix covered only the call paths with OSS read/write and OSS ioctls, while we need to cover the concurrent access via both ALSA and OSS APIs now. This patch addresses the problem above by replacing the buffer_mutex lock in the read/write operations with a refcount similar as we've used for OSS. The new field, runtime->buffer_accessing, keeps the number of concurrent read/write operations. Unlike the former buffer_mutex protection, this protects only around the copy_from/to_user() calls; the other codes are basically protected by the PCM stream lock. The refcount can be a negative, meaning blocked by the ioctls. If a negative value is seen, the read/write aborts with -EBUSY. In the ioctl side, OTOH, they check this refcount, too, and set to a negative value for blocking unless it's already being accessed.

来源：美国国家漏洞数据库 NVD

CVSS信息

N/A

来源：美国国家漏洞数据库 NVD

漏洞类别

N/A

来源：美国国家漏洞数据库 NVD

二、漏洞 CVE-2022-49272 的公开POC

#	POC 描述	源链接	神龙链接

三、漏洞 CVE-2022-49272 的情报信息

标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
https://nvd.nist.gov/vuln/detail/CVE-2022-49272