CVE-2021-47482
Last modified
CVE-2021-47482 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. EPSS estimates a 0.74% chance of exploitation in the next 30 days.
Description
In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.
Metrics
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions | Update |
|---|---|---|---|
| Linux | Linux Kernel | >= 2.6.38, < 4.4.293 | — |
| Linux | Linux Kernel | >= 4.5, < 4.9.289 | — |
| Linux | Linux Kernel | >= 4.10, < 4.14.254 | — |
| Linux | Linux Kernel | >= 4.15, < 4.19.215 | — |
| Linux | Linux Kernel | >= 4.20, < 5.4.157 | — |
| Linux | Linux Kernel | >= 5.5, < 5.10.77 | — |
| Linux | Linux Kernel | >= 5.11, < 5.14.16 | — |
| Linux | Linux Kernel | 5.15 | Rc1 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
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- CVE-2021-47487Rejected reason: This CVE ID has been rejected or withdrawn …
- CVE-2021-47488Rejected reason: This CVE ID has been rejected or withdrawn …
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