Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_tunnel: fix use-after-free on object destroy nft_tunnel_obj_destroy() calls metadata_dst_free() which directly kfree()s the metadata_dst, ignoring the dst_entry refcount. Packets that took a reference via dst_hold() in nft_tunnel_obj_eval() and are still queued (e.g. in a netem qdisc) are left with a dangling pointer. When these packets are eventually dequeued, dst_release() operates on freed memory. Replace metadata_dst_free() with dst_release() so the metadata_dst is freed only after all references are dropped. The dst subsystem already handles metadata_dst cleanup in dst_destroy() when DST_METADATA is set.
CVSS breakdown
CVSS 3.1
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected products
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – 349df61526d2e39decc685d246202e3e284cfe05
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – 55b79b1ae42372012413ce0413181d26679b17ef
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – 5e9ee18b27fde88cb6148202b33916c66693fe82
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – 8767fe4079affa74314d7eb3220e700150289842
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – fda6573a46ad24f35348e024905ee5bdf729797e
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – 941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – f9a0e4b61054cde89a2a77845293c726cc07cc43
- Linux / Linuxaf308b94a2a4a5a27bec9028354c4df444a7c8ba – c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a
- Linux / Linux4.19 – 4.19
- Linux / Linux0 – 4.19
- Linux / Linux5.10.259 – 5.10.*
- Linux / Linux5.15.210 – 5.15.*
- Linux / Linux6.1.176 – 6.1.*
- Linux / Linux6.6.143 – 6.6.*
- Linux / Linux6.12.94 – 6.12.*
- Linux / Linux6.18.36 – 6.18.*
- Linux / Linux7.0.13 – 7.0.*
- Linux / Linux7.1 – *
References
- MISChttps://git.kernel.org/stable/c/349df61526d2e39decc685d246202e3e284cfe05
- MISChttps://git.kernel.org/stable/c/55b79b1ae42372012413ce0413181d26679b17ef
- MISChttps://git.kernel.org/stable/c/5e9ee18b27fde88cb6148202b33916c66693fe82
- MISChttps://git.kernel.org/stable/c/8767fe4079affa74314d7eb3220e700150289842
- MISChttps://git.kernel.org/stable/c/fda6573a46ad24f35348e024905ee5bdf729797e
- MISChttps://git.kernel.org/stable/c/941d7394efda5e054e2d6f3e0dd0f6a9ba19aaa3
- MISChttps://git.kernel.org/stable/c/f9a0e4b61054cde89a2a77845293c726cc07cc43
- MISChttps://git.kernel.org/stable/c/c32b26aaa2f9216520a38b3f4bfeec846eb3eb8a