Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: usb: f_fs: Fix use-after-free for epfile Consider a case where ffs_func_eps_disable is called from ffs_func_disable as part of composition switch and at the same time ffs_epfile_release get called from userspace. ffs_epfile_release will free up the read buffer and call ffs_data_closed which in turn destroys ffs->epfiles and mark it as NULL. While this was happening the driver has already initialized the local epfile in ffs_func_eps_disable which is now freed and waiting to acquire the spinlock. Once spinlock is acquired the driver proceeds with the stale value of epfile and tries to free the already freed read buffer causing use-after-free. Following is the illustration of the race: CPU1 CPU2 ffs_func_eps_disable epfiles (local copy) ffs_epfile_release ffs_data_closed if (last file closed) ffs_data_reset ffs_data_clear ffs_epfiles_destroy spin_lock dereference epfiles Fix this races by taking epfiles local copy & assigning it under spinlock and if epfiles(local) is null then update it in ffs->epfiles then finally destroy it. Extending the scope further from the race, protecting the ep related structures, and concurrent accesses.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 4.9, < 4.14.267 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/0042178a69eb77a979e36a50dcce9794a3140ef8Patch
- https://git.kernel.org/stable/c/32048f4be071f9a6966744243f1786f45bb22dc2Patch
- https://git.kernel.org/stable/c/3e078b18753669615301d946297bafd69294ad2cPatch
- https://git.kernel.org/stable/c/72a8aee863af099d4434314c4536d6c9a61dcf3cPatch
- https://git.kernel.org/stable/c/c9fc422c9a43e3d58d246334a71f3390401781dcPatch
- https://git.kernel.org/stable/c/cfe5f6fd335d882bcc829a1c8a7d462a455c626ePatch
- https://git.kernel.org/stable/c/ebe2b1add1055b903e2acd86b290a85297edc0b3Patch
- https://git.kernel.org/stable/c/0042178a69eb77a979e36a50dcce9794a3140ef8Patch
- https://git.kernel.org/stable/c/32048f4be071f9a6966744243f1786f45bb22dc2Patch
- https://git.kernel.org/stable/c/3e078b18753669615301d946297bafd69294ad2cPatch
- https://git.kernel.org/stable/c/72a8aee863af099d4434314c4536d6c9a61dcf3cPatch
- https://git.kernel.org/stable/c/c9fc422c9a43e3d58d246334a71f3390401781dcPatch
- https://git.kernel.org/stable/c/cfe5f6fd335d882bcc829a1c8a7d462a455c626ePatch
- https://git.kernel.org/stable/c/ebe2b1add1055b903e2acd86b290a85297edc0b3Patch
FAQ
What is CVE-2022-48822?
CVE-2022-48822 is a vulnerability with a CVSS score of 7.8 (HIGH). In the Linux kernel, the following vulnerability has been resolved: usb: f_fs: Fix use-after-free for epfile Consider a case where ffs_func_eps_disable is called from ffs_func_disable as part of com...
How severe is CVE-2022-48822?
CVE-2022-48822 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2022-48822?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.