kernel/linux.git/net/rxrpc, branch v5.10.268

rxrpc: Fix socket notification race

2026-08-23T12:16:19+00:00

[ Upstream commit e66f8f32f50116670dbbee5bc9e692cd2cd0c8f8 ] There's a race between rxrpc_recvmsg() and rxrpc_notify_socket(), whereby the latter's attempt to avoid disabling interrupts and taking the socket's recvmsg_lock if the call is already queued may happen simultaneously with the former's discarding of a call that has nothing queued. Fix this by removing the shortcut. Note that this only affects userspace's use of AF_RXRPC; the AFS filesystem driver doesn't use the socket queue. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix notification vs call-release vs recvmsg

2026-08-23T12:16:19+00:00

[ Upstream commit 2fd895842d49c23137ae48252dd211e5d6d8a3ed ] When a call is released, rxrpc takes the spinlock and removes it from ->recvmsg_q in an effort to prevent racing recvmsg() invocations from seeing the same call. Now, rxrpc_recvmsg() only takes the spinlock when actually removing a call from the queue; it doesn't, however, take it in the lead up to that when it checks to see if the queue is empty. It *does* hold the socket lock, which prevents a recvmsg/recvmsg race - but this doesn't prevent sendmsg from ending the call because sendmsg() drops the socket lock and relies on the call->user_mutex. Fix this by firstly removing the bit in rxrpc_release_call() that dequeues the released call and, instead, rely on recvmsg() to simply discard released calls (done in a preceding fix). Secondly, rxrpc_notify_socket() is abandoned if the call is already marked as released rather than trying to be clever by setting both pointers in call->recvmsg_link to NULL to trick list_empty(). This isn't perfect and can still race, resulting in a released call on the queue, but recvmsg() will now clean that up. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Marc Dionne cc: Junvyyang, Tencent Zhuque Lab cc: LePremierHomme cc: Simon Horman cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250717074350.3767366-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski Stable-dep-of: e66f8f32f501 ("rxrpc: Fix socket notification race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix recv-recv race of completed call

2026-08-23T12:16:19+00:00

[ Upstream commit 962fb1f651c2cf2083e0c3ef53ba69e3b96d3fbc ] If a call receives an event (such as incoming data), the call gets placed on the socket's queue and a thread in recvmsg can be awakened to go and process it. Once the thread has picked up the call off of the queue, further events will cause it to be requeued, and once the socket lock is dropped (recvmsg uses call->user_mutex to allow the socket to be used in parallel), a second thread can come in and its recvmsg can pop the call off the socket queue again. In such a case, the first thread will be receiving stuff from the call and the second thread will be blocked on call->user_mutex. The first thread can, at this point, process both the event that it picked call for and the event that the second thread picked the call for and may see the call terminate - in which case the call will be "released", decoupling the call from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control message). The first thread will return okay, but then the second thread will wake up holding the user_mutex and, if it sees that the call has been released by the first thread, it will BUG thusly: kernel BUG at net/rxrpc/recvmsg.c:474! Fix this by just dequeuing the call and ignoring it if it is seen to be already released. We can't tell userspace about it anyway as the user call ID has become stale. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Reported-by: Junvyyang, Tencent Zhuque Lab Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: LePremierHomme cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250717074350.3767366-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski Stable-dep-of: e66f8f32f501 ("rxrpc: Fix socket notification race") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: serialize kernel accept preallocation with socket teardown

2026-08-23T12:16:19+00:00

[ Upstream commit dc175389b18c29a5303ee83169ec653adfae3e17 ] rxrpc_kernel_charge_accept() reads rx->backlog without any socket/backlog synchronization and passes that raw pointer into rxrpc_service_prealloc_one(). A concurrent rxrpc_discard_prealloc() sets rx->backlog = NULL and frees the backlog rings, so a kernel preallocation worker can keep using a freed struct rxrpc_backlog while updating *_backlog_head/tail and array slots. Serialize the state check and backlog lookup with the socket lock, and reject kernel preallocation once teardown has disabled listening or discarded the service backlog. Fixes: 00e907127e6f ("rxrpc: Preallocate peers, conns and calls for incoming service requests") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Li Daming Signed-off-by: Ren Wei Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260609140911.838677-6-dhowells@redhat.com Signed-off-by: Jakub Kicinski [ kept 6.1's extra user_attach_call argument in the rxrpc_service_prealloc_one() call ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix missing validation of ticket length in non-XDR key preparsing

2026-06-01T15:29:17+00:00

commit ac33733b10b484d666f97688561670afd5861383 upstream. In rxrpc_preparse(), there are two paths for parsing key payloads: the XDR path (for large payloads) and the non-XDR path (for payloads <= 28 bytes). While the XDR path (rxrpc_preparse_xdr_rxkad()) correctly validates the ticket length against AFSTOKEN_RK_TIX_MAX, the non-XDR path fails to do so. This allows an unprivileged user to provide a very large ticket length. When this key is later read via rxrpc_read(), the total token size (toksize) calculation results in a value that exceeds AFSTOKEN_LENGTH_MAX, triggering a WARN_ON(). [ 2001.302904] WARNING: CPU: 2 PID: 2108 at net/rxrpc/key.c:778 rxrpc_read+0x109/0x5c0 [rxrpc] Fix this by adding a check in the non-XDR parsing path of rxrpc_preparse() to ensure the ticket length does not exceed AFSTOKEN_RK_TIX_MAX, bringing it into parity with the XDR parsing logic. Fixes: 8a7a3eb4ddbe ("KEYS: RxRPC: Use key preparsing") Fixes: 84924aac08a4 ("rxrpc: Fix checker warning") Reported-by: Anderson Nascimento Signed-off-by: Anderson Nascimento Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260422161438.2593376-7-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix anonymous key handling

2026-06-01T15:29:16+00:00

[ Upstream commit 6a59d84b4fc2f27f7b40e348506cc686712e260b ] In rxrpc_new_client_call_for_sendmsg(), a key with no payload is meant to be substituted for a NULL key pointer, but the variable this is done with is subsequently not used. Fix this by using "key" rather than "rx->key" when filling in the connection parameters. Note that this only affects direct use of AF_RXRPC; the kAFS filesystem doesn't use sendmsg() directly and so bypasses the issue. Further, AF_RXRPC passes a NULL key in if no key is set, so using an anonymous key in that manner works. Since this hasn't been noticed to this point, it might be better just to remove the "key" variable and the code that sets it - and, arguably, rxrpc_init_client_call_security() would be a better place to handle it. Fixes: 19ffa01c9c45 ("rxrpc: Use structs to hold connection params and protocol info") Closes: https://sashiko.dev/#/patchset/20260319150150.4189381-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: only handle RESPONSE during service challenge

2026-06-01T15:29:16+00:00

[ Upstream commit c43ffdcfdbb5567b1f143556df8a04b4eeea041c ] Only process RESPONSE packets while the service connection is still in RXRPC_CONN_SERVICE_CHALLENGING. Check that state under state_lock before running response verification and security initialization, then use a local secured flag to decide whether to queue the secured-connection work after the state transition. This keeps duplicate or late RESPONSE packets from re-running the setup path and removes the unlocked post-transition state test. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Jie Wang Signed-off-by: Yang Yang Signed-off-by: David Howells cc: Marc Dionne cc: Jeffrey Altman cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-21-dhowells@redhat.com Signed-off-by: Jakub Kicinski [ adapted to spin_lock_bh usage, 3-arg verify_response(), and direct rxrpc_call_is_secure() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: Fix recvmsg() unconditional requeue

2026-06-01T15:29:16+00:00

[ Upstream commit 2c28769a51deb6022d7fbd499987e237a01dd63a ] If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at the front of the recvmsg queue already has its mutex locked, it requeues the call - whether or not the call is already queued. The call may be on the queue because MSG_PEEK was also passed and so the call was not dequeued or because the I/O thread requeued it. The unconditional requeue may then corrupt the recvmsg queue, leading to things like UAFs or refcount underruns. Fix this by only requeuing the call if it isn't already on the queue - and moving it to the front if it is already queued. If we don't queue it, we have to put the ref we obtained by dequeuing it. Also, MSG_PEEK doesn't dequeue the call so shouldn't call rxrpc_notify_socket() for the call if we didn't use up all the data on the queue, so fix that also. Fixes: 540b1c48c37a ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg") Reported-by: Faith Reported-by: Pumpkin Chang Signed-off-by: David Howells Acked-by: Marc Dionne Signed-off-by: Jakub Kicinski Cc: stable@vger.kernel.org [Adapted to 5.10: use write_lock_bh/write_unlock_bh, trace_rxrpc_call directly for see-call tracing, 5.10 trace enum naming convention, and added entries to both plain enum and EM() macro list.] Signed-off-by: Jay Wang Signed-off-by: Sasha Levin

rxrpc: reject undecryptable rxkad response tickets

2026-06-01T15:29:15+00:00

[ Upstream commit fe4447cd95623b1cfacc15f280aab73a6d7340b2 ] rxkad_decrypt_ticket() decrypts the RXKAD response ticket and then parses the buffer as plaintext without checking whether crypto_skcipher_decrypt() succeeded. A malformed RESPONSE can therefore use a non-block-aligned ticket length, make the decrypt operation fail, and still drive the ticket parser with attacker-controlled bytes. Check the decrypt result and abort the connection with RXKADBADTICKET when ticket decryption fails. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Ren Wei Signed-off-by: Yuqi Xu Signed-off-by: Ren Wei Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-12-dhowells@redhat.com Signed-off-by: Jakub Kicinski [ adapted `rxrpc_abort_conn()` call to existing `goto other_error` error-handling pattern ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

rxrpc: fix reference count leak in rxrpc_server_keyring()

2026-06-01T15:29:14+00:00

[ Upstream commit f125846ee79fcae537a964ce66494e96fa54a6de ] This patch fixes a reference count leak in rxrpc_server_keyring() by checking if rx->securities is already set. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Ren Wei Signed-off-by: Luxiao Xu Signed-off-by: Ren Wei Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-15-dhowells@redhat.com Signed-off-by: Jakub Kicinski [ applied patch to net/rxrpc/key.c instead of net/rxrpc/server_key.c ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman