CVE-2022-48822
usb: f_fs: Fix use-after-free for epfile
- Published
- Updated
- Reserved
- Assigned by
- Linux
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < 32048f4be071f9a6966744243f1786f45bb22dc2
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < cfe5f6fd335d882bcc829a1c8a7d462a455c626e
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < c9fc422c9a43e3d58d246334a71f3390401781dc
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < 0042178a69eb77a979e36a50dcce9794a3140ef8
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < 72a8aee863af099d4434314c4536d6c9a61dcf3c
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < 3e078b18753669615301d946297bafd69294ad2c
- affected a9e6f83c2df199187a5248f824f31b6787ae23ae – < ebe2b1add1055b903e2acd86b290a85297edc0b3
- affected 5cd8f6788ff34999dbd4cbec81a6adfc215e1e60
- affected 4.8.10 – < 4.9
- affected 4.9
- unaffected < 4.9
- unaffected 4.14.267 – ≤ 4.14.*
- unaffected 4.19.230 – ≤ 4.19.*
- unaffected 5.4.180 – ≤ 5.4.*
- unaffected 5.10.101 – ≤ 5.10.*
- unaffected 5.15.24 – ≤ 5.15.*
- unaffected 5.16.10 – ≤ 5.16.*
- unaffected 5.17 – ≤ *
References (7)
- https://git.kernel.org/stable/c/32048f4be071f9a6966744243f1786f45bb22dc2 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/cfe5f6fd335d882bcc829a1c8a7d462a455c626e (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/c9fc422c9a43e3d58d246334a71f3390401781dc (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/0042178a69eb77a979e36a50dcce9794a3140ef8 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/72a8aee863af099d4434314c4536d6c9a61dcf3c (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/3e078b18753669615301d946297bafd69294ad2c (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/ebe2b1add1055b903e2acd86b290a85297edc0b3 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2022-48822)Record last updated .