| Summary: |
VUL-0: CVE-2022-48822: kernel: usb: f_fs: fix use-after-free for epfile |
| Product: |
[Novell Products] SUSE Security Incidents
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Reporter: |
SMASH SMASH <smash_bz> |
| Component: |
Incidents | Assignee: |
Oliver Neukum <oneukum> |
| Status: |
NEW
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QA Contact: |
Security Team bot <security-team> |
| Severity: |
Major
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| Priority: |
P2 - High
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CC: |
camila.matos, meissner, miroslav.franc, oneukum
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| Version: |
unspecified | |
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| Target Milestone: |
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| Hardware: |
Other | |
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| OS: |
Other | |
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| URL: |
https://smash.suse.de/issue/414245/
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| Whiteboard: |
CVSSv3.1:SUSE:CVE-2022-48822:7.0:(AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) |
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Found By:
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Security Response Team
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Services Priority:
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Business Priority:
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Blocker:
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Marketing QA Status:
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IT Deployment:
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| Bug Depends on: |
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| Bug Blocks: |
1228136
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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. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2022-48822 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2022/CVE-2022-48822.mbox https://git.kernel.org/stable/c/32048f4be071f9a6966744243f1786f45bb22dc2 https://git.kernel.org/stable/c/cfe5f6fd335d882bcc829a1c8a7d462a455c626e https://git.kernel.org/stable/c/c9fc422c9a43e3d58d246334a71f3390401781dc https://git.kernel.org/stable/c/0042178a69eb77a979e36a50dcce9794a3140ef8 https://git.kernel.org/stable/c/72a8aee863af099d4434314c4536d6c9a61dcf3c https://git.kernel.org/stable/c/3e078b18753669615301d946297bafd69294ad2c https://git.kernel.org/stable/c/ebe2b1add1055b903e2acd86b290a85297edc0b3 https://www.cve.org/CVERecord?id=CVE-2022-48822 https://bugzilla.redhat.com/show_bug.cgi?id=2298161