Bug 2173973 (CVE-2023-1095) - CVE-2023-1095 kernel: netfilter: NULL pointer dereference in nf_tables due to zeroed list head
Summary: CVE-2023-1095 kernel: netfilter: NULL pointer dereference in nf_tables due to...
Keywords:
Status: NEW
Alias: CVE-2023-1095
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
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Depends On: Red Hat2072549 Red Hat2121393 Red Hat2173999 Red Hat2174000 Red Hat2174001 Red Hat2174002
Blocks: Embargoed2154244
TreeView+ depends on / blocked
 
Reported: 2023-02-28 14:55 UTC by Mauro Matteo Cascella
Modified: 2023-04-01 08:44 UTC (History)
36 users (show)

Fixed In Version: kernel 6.0-rc1
Doc Type: If docs needed, set a value
Doc Text:
A NULL pointer dereference flaw was found in the Linux kernel’s netfilter subsystem. The issue could occur due to an error in nf_tables_updtable while freeing a transaction object not placed on the list head. This flaw allows a local, unprivileged user to crash the system, resulting in a denial of service.
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Description Mauro Matteo Cascella 2023-02-28 14:55:06 UTC 
In nf_tables_updtable, if nf_tables_table_enable returns an error, nft_trans_destroy is called to free the transaction object. nft_trans_destroy() calls list_del(), but the transaction was never placed on a list -- the list head is all zeroes, this results in a NULL pointer dereference.

Upstream patch & commit:
https://lore.kernel.org/netfilter-devel/20220809163402.20227-1-fw@strlen.de/
https://github.com/torvalds/linux/commit/580077855a40741cf511766129702d97ff02f4d9
Comment 4 Mauro Matteo Cascella 2023-02-28 16:36:29 UTC 
This issue was fixed upstream in version 6.0. The kernel packages as shipped in Red Hat Enterprise Linux 9 were previously updated to a version that contains the fix via the following errata:

kernel in Red Hat Enterprise Linux 9
https://access.redhat.com/errata/RHSA-2022:8267

kernel-rt in Red Hat Enterprise Linux 9
https://access.redhat.com/errata/RHSA-2022:7933
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