Bug 2492388 (CVE-2026-52974)

Summary: CVE-2026-52974 kernel: net: tls: fix strparser anchor skb leak on offload RX setup failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's network Transport Layer Security (TLS) module. Specifically, a memory leak occurs during the setup of receive offload when a particular function fails. This issue can lead to the gradual consumption of system memory. If exploited repeatedly, this could result in a Denial of Service (DoS), making the system unavailable to legitimate users.
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Description OSIDB Bzimport 2026-06-24 18:09:21 UTC
In the Linux kernel, the following vulnerability has been resolved:

net: tls: fix strparser anchor skb leak on offload RX setup failure

When tls_set_device_offload_rx() fails at tls_dev_add(), the error path
calls tls_sw_free_resources_rx() to clean up the SW context that was
initialized by tls_set_sw_offload(). This function calls
tls_sw_release_resources_rx() (which stops the strparser via
tls_strp_stop()) and tls_sw_free_ctx_rx() (which kfrees the context),
but never frees the anchor skb that was allocated by alloc_skb(0) in
tls_strp_init().

Note that tls_sw_free_resources_rx() is exclusively used for this
"failed to start offload" code path, there's no other caller.

The leak did not exist before commit 84c61fe1a75b ("tls: rx: do not use
the standard strparser"), because the standard strparser doesn't try
to pre-allocate an skb.

The normal close path in tls_sk_proto_close() handles cleanup by calling
tls_sw_strparser_done() (which calls tls_strp_done()) after dropping
the socket lock, because tls_strp_done() does cancel_work_sync() and
the strparser work handler takes the socket lock.

Comment 1 Mauro Matteo Cascella 2026-06-26 15:27:22 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062440-CVE-2026-52974-f4e7@gregkh/T