CVE-2021-47482
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().
Does this matter?
Lower severity and a low EPSS score (0.74%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.74% probability · 53th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-544
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20Patch
- https://git.kernel.org/stable/c/0c6b199f09be489c48622537a550787fc80aea73Patch
- https://git.kernel.org/stable/c/6422e8471890273994fe8cc6d452b0dcd2c9483ePatch
- https://git.kernel.org/stable/c/6f68cd634856f8ca93bafd623ba5357e0f648c68Patch
- https://git.kernel.org/stable/c/a8f7359259dd5923adc6129284fdad12fc5db347Patch
- https://git.kernel.org/stable/c/b0a2cd38553c77928ef1646ed1518486b1e70ae8Patch
- https://git.kernel.org/stable/c/e50f957652190b5a88a8ebce7e5ab14ebd0d3f00Patch
- https://git.kernel.org/stable/c/fbf150b16a3635634b7dfb7f229d8fcd643c6c51Patch
- https://git.kernel.org/stable/c/07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20Patch
- https://git.kernel.org/stable/c/0c6b199f09be489c48622537a550787fc80aea73Patch
- https://git.kernel.org/stable/c/6422e8471890273994fe8cc6d452b0dcd2c9483ePatch
- https://git.kernel.org/stable/c/6f68cd634856f8ca93bafd623ba5357e0f648c68Patch
- https://git.kernel.org/stable/c/a8f7359259dd5923adc6129284fdad12fc5db347Patch
- https://git.kernel.org/stable/c/b0a2cd38553c77928ef1646ed1518486b1e70ae8Patch
- https://git.kernel.org/stable/c/e50f957652190b5a88a8ebce7e5ab14ebd0d3f00Patch
- https://git.kernel.org/stable/c/fbf150b16a3635634b7dfb7f229d8fcd643c6c51Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.