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2026-06-25rxrpc: Fix leak of released call in recvmsg(MSG_PEEK)David Howells1-2/+1
Fix rxrpc_recvmsg() to also drop the ref it holds on an already-released call if MSG_PEEK is in force (the function holds a ref on the call irrespective of whether MSG_PEEK is specified or not). Fixes: 962fb1f651c2 ("rxrpc: Fix recv-recv race of completed call") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-11-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix socket notification raceDavid Howells1-2/+0
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 <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> 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 <kuba@kernel.org>
2026-06-25rxrpc: Fix potential infinite loop in rxrpc_recvmsg()David Howells1-1/+2
Fix the wait in rxrpc_recvmsg() also take check the oob queue. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-9-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix double unlock in rxrpc_recvmsg()David Howells1-1/+1
Fix a double unlock in rxrpc_recvmsg() when dealing with OOB messages. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260609140911.838677-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-12rxrpc: Don't move a peeked OOB message onto the pending queueHyunwoo Kim1-5/+6
rxrpc_recvmsg_oob() takes a received oob message off recvmsg_oobq and, if a response is needed, moves it onto the pending_oobq tree. However, only the unlink from recvmsg_oobq is guarded by MSG_PEEK; the move onto pending_oobq always runs. As a result, reading a challenge with MSG_PEEK leaves the skb on recvmsg_oobq while also adding it to pending_oobq. Since struct sk_buff's rbnode shares storage with its next and prev pointers, rb_insert_color() overwrites the list linkage, and the skb, which holds a single reference, becomes reachable from both queues at once. When the socket is closed both queues are drained in turn. While draining recvmsg_oobq, __skb_unlink() follows the next and prev pointers that rbnode has overwritten and writes to a bad address. Also, as the skb holds a single reference but is freed from each queue, both the skb and the connection reference it holds are released twice. This leads to memory corruption and to a use-after-free caused by the connection refcount underflow. MSG_PEEK does not consume the message from the queue, so only unlink it from recvmsg_oobq and then move it onto pending_oobq or free it when the message is actually consumed. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260609140911.838677-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-12rxrpc: rxrpc_verify_data ensure rx_dec_buffer allocJeffrey Altman1-1/+1
rxrpc_recvmsg_data() calls rxrpc_verify_data() whenever the rxrpc_call.rx_dec_buffer is unallocated and assumes that upon successful return that rx_dec_buffer must be allocated. However, rxrpc_verify_data() does not request an allocation if the rxrpc_skb_priv.len is zero. In addition, failure to allocate rx_dec_buffer will result in a call to skb_copy_bits() with a NULL destination which can trigger a NULL pointer dereference. To prevent these issues rxrpc_verify_data() is modified to always attempt to allocate the rxrpc_call.rx_dec_buffer if it is NULL. This issue was identified with assistance of a private sashiko instance. Fixes: d2bc90cf6c75cb ("rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg") Reported-by: Simon Horman <simon.horman@redhat.com> Signed-off-by: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Jiayuan Chen <jiayuan.chen@linux.dev> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260609140911.838677-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-20rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsgDavid Howells1-13/+55
This improves the fix for CVE-2026-43500. Fix the pagecache corruption from in-place decryption of a DATA packet transmitted locally by splice() by getting rid of the packet sharing in the I/O thread and unconditionally extracting the packet content into a bounce buffer in which the buffer is decrypted. recvmsg() (or the kernel equivalent) then copies the data from the bounce buffer to the destination buffer. The sk_buff then remains unmodified. This has an additional advantage in that the packet is then arranged in the buffer with the correct alignment required for the crypto algorithms to process directly. The performance of the crypto does seem to be a little faster and, surprisingly, the unencrypted performance doesn't seem to change much - possibly due to removing complexity from the I/O thread. Yet another advantage is that the I/O thread doesn't have to copy packets which would slow down packet distribution, ACK generation, etc.. The buffer belongs to the call and is allocated initially at 2K, sufficiently large to hold a whole jumbo subpacket, but the buffer will be increased in size if needed. However, to take this work, MSG_PEEK may cause a later packet to be decrypted into the buffer, in which case the earlier one will need re-decrypting for a subsequent recvmsg(). Note that rx_pkt_offset may legitimately see 0 as a valid offset now, so switch to using USHRT_MAX to indicate an invalid offset. Note also that I would generally prefer to replace the buffers of the current sk_buff with a new kmalloc'd buffer of the right size, ditching the old data and frags as this makes the handling of MSG_PEEK easier and removes the re-decryption issue, but this looks like quite a complicated thing to achieve. skb_morph() looks half way to what I want, but I don't want to have to allocate a new sk_buff. Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()") Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Closes: https://lore.kernel.org/r/afKV2zGR6rrelPC7@v4bel/ Signed-off-by: David Howells <dhowells@redhat.com> cc: Simon Horman <horms@kernel.org> cc: Jiayuan Chen <jiayuan.chen@linux.dev> cc: linux-afs@lists.infradead.org Reviewed-by: Jeffrey Altman <jaltman@auristor.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Link: https://patch.msgid.link/20260515230516.2718212-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-19rxrpc: Fix recvmsg() unconditional requeueDavid Howells1-4/+15
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 <faith@zellic.io> Reported-by: Pumpkin Chang <pumpkin@devco.re> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Marc Dionne <marc.dionne@auristor.com> cc: Nir Ohfeld <niro@wiz.io> cc: Willy Tarreau <w@1wt.eu> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/95163.1768428203@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17rxrpc: Fix notification vs call-release vs recvmsgDavid Howells1-0/+4
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 <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com> cc: LePremierHomme <kwqcheii@proton.me> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250717074350.3767366-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17rxrpc: Fix recv-recv race of completed callDavid Howells1-2/+17
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 <zhuque@tencent.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeffrey Altman <jaltman@auristor.com> cc: LePremierHomme <kwqcheii@proton.me> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250717074350.3767366-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSEDavid Howells1-18/+102
Allow the app to request that CHALLENGEs be passed to it through an out-of-band queue that allows recvmsg() to pick it up so that the app can add data to it with sendmsg(). This will allow the application (AFS or userspace) to interact with the process if it wants to and put values into user-defined fields. This will be used by AFS when talking to a fileserver to supply that fileserver with a crypto key by which callback RPCs can be encrypted (ie. notifications from the fileserver to the client). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250411095303.2316168-5-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14rxrpc: kdoc: Update function descriptions and add link from rxrpc.rstDavid Howells1-6/+6
Update the kerneldoc function descriptions to add "Return:" sections for AF_RXRPC exported functions that have return values to stop the kdoc builder from throwing warnings. Also add links from the rxrpc.rst API doc to add a function API reference at the end. (Note that the API doc really needs updating, but that's beyond this patchset). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250411095303.2316168-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-12-09rxrpc: Use irq-disabling spinlocks between app and I/O threadDavid Howells1-9/+9
Where a spinlock is used by both the application thread and the I/O thread, use irq-disabling locking so that an interrupt taken on the app thread doesn't also slow down the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-20rxrpc: Fix overproduction of wakeups to recvmsg()David Howells1-1/+15
Fix three cases of overproduction of wakeups: (1) rxrpc_input_split_jumbo() conditionally notifies the app that there's data for recvmsg() to collect if it queues some data - and then its only caller, rxrpc_input_data(), goes and wakes up recvmsg() anyway. Fix the rxrpc_input_data() to only do the wakeup in failure cases. (2) If a DATA packet is received for a call by the I/O thread whilst recvmsg() is busy draining the call's rx queue in the app thread, the call will left on the recvmsg() queue for recvmsg() to pick up, even though there isn't any data on it. This can cause an unexpected recvmsg() with a 0 return and no MSG_EOR set after the reply has been posted to a service call. Fix this by discarding pending calls from the recvmsg() queue that don't need servicing yet. (3) Not-yet-completed calls get requeued after having data read from them, even if they have no data to read. Fix this by only requeuing them if they have data waiting on them; if they don't, the I/O thread will requeue them when data arrives or they fail. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/3386149.1676497685@warthog.procyon.org.uk Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-07rxrpc: Reduce unnecessary ack transmissionDavid Howells1-1/+1
rxrpc_recvmsg_data() schedules an ACK to be transmitted every time at least two packets have been consumed and any time it runs out of data and would return -EAGAIN to the caller. Both events may occur within a single loop, however, and if the I/O thread is quick enough it may send duplicate ACKs. The ACKs are sent to inform the peer that more space has been made in the local Rx window, but the I/O thread is going to send an ACK every couple of DATA packets anyway, so we end up sending a lot more ACKs than we really need to. So reduce the rate at which recvmsg() schedules ACKs, such that if the I/O thread sends ACKs at its normal faster rate, recvmsg() won't actually schedule ACKs until the Rx flow stops (call->rx_consumed is cleared any time we transmit an ACK for that call, resetting the counter used by recvmsg). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: De-atomic call->ackr_window and call->ackr_nr_unackedDavid Howells1-3/+3
call->ackr_window doesn't need to be atomic as ACK generation and ACK transmission are now done in the same thread, so drop the atomic64 handling and split it into two separate members. Similarly, call->ackr_nr_unacked doesn't need to be atomic now either. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-31rxrpc: Convert call->recvmsg_lock to a spinlockDavid Howells1-6/+6
Convert call->recvmsg_lock to a spinlock as it's only ever write-locked. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Move call state changes from recvmsg to I/O threadDavid Howells1-106/+62
Move the call state changes that are made in rxrpc_recvmsg() to the I/O thread. This means that, thenceforth, only the I/O thread does this and the call state lock can be removed. This requires the Rx phase to be ended when the last packet is received, not when it is processed. Since this now changes the rxrpc call state to SUCCEEDED before we've consumed all the data from it, rxrpc_kernel_check_life() mustn't say the call is dead until the recvmsg queue is empty (unless the call has failed). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Wrap accesses to get call state to put the barrier in one placeDavid Howells1-6/+6
Wrap accesses to get the state of a call from outside of the I/O thread in a single place so that the barrier needed to order wrt the error code and abort code is in just that place. Also use a barrier when setting the call state and again when reading the call state such that the auxiliary completion info (error code, abort code) can be read without taking a read lock on the call state lock. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Split out the call state changing functions into their own fileDavid Howells1-81/+0
Split out the functions that change the state of an rxrpc call into their own file. The idea being to remove anything to do with changing the state of a call directly from the rxrpc sendmsg() and recvmsg() paths and have all that done in the I/O thread only, with the ultimate aim of removing the state lock entirely. Moving the code out of sendmsg.c and recvmsg.c makes that easier to manage. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Tidy up abort generation infrastructureDavid Howells1-7/+11
Tidy up the abort generation infrastructure in the following ways: (1) Create an enum and string mapping table to list the reasons an abort might be generated in tracing. (2) Replace the 3-char string with the values from (1) in the places that use that to log the abort source. This gets rid of a memcpy() in the tracepoint. (3) Subsume the rxrpc_rx_eproto tracepoint with the rxrpc_abort tracepoint and use values from (1) to indicate the trace reason. (4) Always make a call to an abort function at the point of the abort rather than stashing the values into variables and using goto to get to a place where it reported. The C optimiser will collapse the calls together as appropriate. The abort functions return a value that can be returned directly if appropriate. Note that this extends into afs also at the points where that generates an abort. To aid with this, the afs sources need to #define RXRPC_TRACE_ONLY_DEFINE_ENUMS before including the rxrpc tracing header because they don't have access to the rxrpc internal structures that some of the tracepoints make use of. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Only disconnect calls in the I/O threadDavid Howells1-0/+1
Only perform call disconnection in the I/O thread to reduce the locking requirement. This is the first part of a fix for a race that exists between call connection and call disconnection whereby the data transmission code adds the call to the peer error distribution list after the call has been disconnected (say by the rxrpc socket getting closed). The fix is to complete the process of moving call connection, data transmission and call disconnection into the I/O thread and thus forcibly serialising them. Note that the issue may predate the overhaul to an I/O thread model that were included in the merge window for v6.2, but the timing is very much changed by the change given below. Fixes: cf37b5987508 ("rxrpc: Move DATA transmission into call processor work item") Reported-by: syzbot+c22650d2844392afdcfd@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2023-01-06rxrpc: Only set/transmit aborts in the I/O threadDavid Howells1-0/+2
Only set the abort call completion state in the I/O thread and only transmit ABORT packets from there. rxrpc_abort_call() can then be made to actually send the packet. Further, ABORT packets should only be sent if the call has been exposed to the network (ie. at least one attempted DATA transmission has occurred for it). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-28rxrpc: Fix a couple of potential use-after-freesDavid Howells1-6/+8
At the end of rxrpc_recvmsg(), if a call is found, the call is put and then a trace line is emitted referencing that call in a couple of places - but the call may have been deallocated by the time those traces happen. Fix this by stashing the call debug_id in a variable and passing that to the tracepoint rather than the call pointer. Fixes: 849979051cbc ("rxrpc: Add a tracepoint to follow what recvmsg does") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2022-12-01rxrpc: Transmit ACKs at the point of generationDavid Howells1-3/+0
For ACKs generated inside the I/O thread, transmit the ACK at the point of generation. Where the ACK is generated outside of the I/O thread, it's offloaded to the I/O thread to transmit it. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Remove the _bh annotation from all the spinlocksDavid Howells1-18/+18
None of the spinlocks in rxrpc need a _bh annotation now as the RCU callback routines no longer take spinlocks and the bulk of the packet wrangling code is now run in the I/O thread, not softirq context. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Make the I/O thread take over the call and local processor workDavid Howells1-6/+3
Move the functions from the call->processor and local->processor work items into the domain of the I/O thread. The call event processor, now called from the I/O thread, then takes over the job of cranking the call state machine, processing incoming packets and transmitting DATA, ACK and ABORT packets. In a future patch, rxrpc_send_ACK() will transmit the ACK on the spot rather than queuing it for later transmission. The call event processor becomes purely received-skb driven. It only transmits things in response to events. We use "pokes" to queue a dummy skb to make it do things like start/resume transmitting data. Timer expiry also results in pokes. The connection event processor, becomes similar, though crypto events, such as dealing with CHALLENGE and RESPONSE packets is offloaded to a work item to avoid doing crypto in the I/O thread. The local event processor is removed and VERSION response packets are generated directly from the packet parser. Similarly, ABORTs generated in response to protocol errors will be transmitted immediately rather than being pushed onto a queue for later transmission. Changes: ======== ver #2) - Fix a couple of introduced lock context imbalances. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Copy client call parameters into rxrpc_call earlierDavid Howells1-5/+3
Copy client call parameters into rxrpc_call earlier so that that can be used to convey them to the connection code - which can then be offloaded to the I/O thread. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for sk_buff tracingDavid Howells1-3/+3
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the sk_buff tracepoint. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: trace: Don't use __builtin_return_address for rxrpc_call tracingDavid Howells1-4/+4
In rxrpc tracing, use enums to generate lists of points of interest rather than __builtin_return_address() for the rxrpc_call tracepoint Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-12-01rxrpc: Remove handling of duplicate packets in recvmsg_queueDavid Howells1-18/+0
We should not now see duplicate packets in the recvmsg_queue. At one point, jumbo packets that overlapped with already queued data would be added to the queue and dealt with in recvmsg rather than in the softirq input code, but now jumbo packets are split/cloned before being processed by the input code and the subpackets can be discarded individually. So remove the recvmsg-side code for handling this. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Get rid of the Rx ringDavid Howells1-57/+60
Get rid of the Rx ring and replace it with a pair of queues instead. One queue gets the packets that are in-sequence and are ready for processing by recvmsg(); the other queue gets the out-of-sequence packets for addition to the first queue as the holes get filled. The annotation ring is removed and replaced with a SACK table. The SACK table has the bits set that correspond exactly to the sequence number of the packet being acked. The SACK ring is copied when an ACK packet is being assembled and rotated so that the first ACK is in byte 0. Flow control handling is altered so that packets that are moved to the in-sequence queue are hard-ACK'd even before they're consumed - and then the Rx window size in the ACK packet (rsize) is shrunk down to compensate (even going to 0 if the window is full). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Clone received jumbo subpackets and queue separatelyDavid Howells1-90/+14
Split up received jumbo packets into separate skbuffs by cloning the original skbuff for each subpacket and setting the offset and length of the data in that subpacket in the skbuff's private data. The subpackets are then placed on the recvmsg queue separately. The security class then gets to revise the offset and length to remove its metadata. If we fail to clone a packet, we just drop it and let the peer resend it. The original packet gets used for the final subpacket. This should make it easier to handle parallel decryption of the subpackets. It also simplifies the handling of lost or misordered packets in the queuing/buffering loop as the possibility of overlapping jumbo packets no longer needs to be considered. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Split the rxrpc_recvmsg tracepointDavid Howells1-19/+18
Split the rxrpc_recvmsg tracepoint so that the tracepoints that are about data packet processing (and which have extra pieces of information) are separate from the tracepoint that shows the general flow of recvmsg(). Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Clean up ACK handlingDavid Howells1-8/+6
Clean up the rxrpc_propose_ACK() function. If deferred PING ACK proposal is split out, it's only really needed for deferred DELAY ACKs. All other ACKs, bar terminal IDLE ACK are sent immediately. The deferred IDLE ACK submission can be handled by conversion of a DELAY ACK into an IDLE ACK if there's nothing to be SACK'd. Also, because there's a delay between an ACK being generated and being transmitted, it's possible that other ACKs of the same type will be generated during that interval. Apart from the ACK time and the serial number responded to, most of the ACK body, including window and SACK parameters, are not filled out till the point of transmission - so we can avoid generating a new ACK if there's one pending that will cover the SACK data we need to convey. Therefore, don't propose a new DELAY or IDLE ACK for a call if there's one already pending. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Allocate ACK records at proposal and queue for transmissionDavid Howells1-23/+10
Allocate rxrpc_txbuf records for ACKs and put onto a queue for the transmitter thread to dispatch. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-11-08rxrpc: Remove call->tx_phaseDavid Howells1-1/+0
Remove call->tx_phase as it's only ever set. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org
2022-09-01rxrpc: Remove rxrpc_get_reply_time() which is no longer usedDavid Howells1-43/+0
Remove rxrpc_get_reply_time() as that is no longer used now that the call issue time is used instead of the reply time. Signed-off-by: David Howells <dhowells@redhat.com>
2022-05-22rxrpc: Fix decision on when to generate an IDLE ACKDavid Howells1-5/+3
Fix the decision on when to generate an IDLE ACK by keeping a count of the number of packets we've received, but not yet soft-ACK'd, and the number of packets we've processed, but not yet hard-ACK'd, rather than trying to keep track of which DATA sequence numbers correspond to those points. We then generate an ACK when either counter exceeds 2. The counters are both cleared when we transcribe the information into any sort of ACK packet for transmission. IDLE and DELAY ACKs are skipped if both counters are 0 (ie. no change). Fixes: 805b21b929e2 ("rxrpc: Send an ACK after every few DATA packets we receive") Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-23afs: Don't truncate iter during data fetchDavid Howells1-4/+5
Don't truncate the iterator to correspond to the actual data size when fetching the data from the server - rather, pass the length we want to read to rxrpc. This will allow the clear-after-read code in future to simply clear the remaining iterator capacity rather than having to reinitialise the iterator. Signed-off-by: David Howells <dhowells@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/158861249201.340223.13035445866976590375.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465825061.1377938.14403904452300909320.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588531418.3465195.10712005940763063144.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118148567.1232039.13380313332292947956.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161044610.2537118.17908520793806837792.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340407907.1303470.6501394859511712746.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539551721.286939.14655713136572200716.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653807790.2770958.14034599989374173734.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789090823.6155.15673999934535049102.stgit@warthog.procyon.org.uk/ # v6
2020-12-09net: rxrpc: convert comma to semicolonZheng Yongjun1-1/+1
Replace a comma between expression statements by a semicolon. Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-05rxrpc: Fix accept on a connection that need securingDavid Howells1-35/+1
When a new incoming call arrives at an userspace rxrpc socket on a new connection that has a security class set, the code currently pushes it onto the accept queue to hold a ref on it for the socket. This doesn't work, however, as recvmsg() pops it off, notices that it's in the SERVER_SECURING state and discards the ref. This means that the call runs out of refs too early and the kernel oopses. By contrast, a kernel rxrpc socket manually pre-charges the incoming call pool with calls that already have user call IDs assigned, so they are ref'd by the call tree on the socket. Change the mode of operation for userspace rxrpc server sockets to work like this too. Although this is a UAPI change, server sockets aren't currently functional. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-30rxrpc: Fix race between recvmsg and sendmsg on immediate call failureDavid Howells1-1/+1
There's a race between rxrpc_sendmsg setting up a call, but then failing to send anything on it due to an error, and recvmsg() seeing the call completion occur and trying to return the state to the user. An assertion fails in rxrpc_recvmsg() because the call has already been released from the socket and is about to be released again as recvmsg deals with it. (The recvmsg_q queue on the socket holds a ref, so there's no problem with use-after-free.) We also have to be careful not to end up reporting an error twice, in such a way that both returns indicate to userspace that the user ID supplied with the call is no longer in use - which could cause the client to malfunction if it recycles the user ID fast enough. Fix this by the following means: (1) When sendmsg() creates a call after the point that the call has been successfully added to the socket, don't return any errors through sendmsg(), but rather complete the call and let recvmsg() retrieve them. Make sendmsg() return 0 at this point. Further calls to sendmsg() for that call will fail with ESHUTDOWN. Note that at this point, we haven't send any packets yet, so the server doesn't yet know about the call. (2) If sendmsg() returns an error when it was expected to create a new call, it means that the user ID wasn't used. (3) Mark the call disconnected before marking it completed to prevent an oops in rxrpc_release_call(). (4) recvmsg() will then retrieve the error and set MSG_EOR to indicate that the user ID is no longer known by the kernel. An oops like the following is produced: kernel BUG at net/rxrpc/recvmsg.c:605! ... RIP: 0010:rxrpc_recvmsg+0x256/0x5ae ... Call Trace: ? __init_waitqueue_head+0x2f/0x2f ____sys_recvmsg+0x8a/0x148 ? import_iovec+0x69/0x9c ? copy_msghdr_from_user+0x5c/0x86 ___sys_recvmsg+0x72/0xaa ? __fget_files+0x22/0x57 ? __fget_light+0x46/0x51 ? fdget+0x9/0x1b do_recvmmsg+0x15e/0x232 ? _raw_spin_unlock+0xa/0xb ? vtime_delta+0xf/0x25 __x64_sys_recvmmsg+0x2c/0x2f do_syscall_64+0x4c/0x78 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 357f5ef64628 ("rxrpc: Call rxrpc_release_call() on error in rxrpc_new_client_call()") Reported-by: syzbot+b54969381df354936d96@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-20rxrpc: Fix sendmsg() returning EPIPE due to recvmsg() returning ENODATADavid Howells1-1/+1
rxrpc_sendmsg() returns EPIPE if there's an outstanding error, such as if rxrpc_recvmsg() indicating ENODATA if there's nothing for it to read. Change rxrpc_recvmsg() to return EAGAIN instead if there's nothing to read as this particular error doesn't get stored in ->sk_err by the networking core. Also change rxrpc_sendmsg() so that it doesn't fail with delayed receive errors (there's no way for it to report which call, if any, the error was caused by). Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-05rxrpc: Fix missing notificationDavid Howells1-8/+13
Under some circumstances, rxrpc will fail a transmit a packet through the underlying UDP socket (ie. UDP sendmsg returns an error). This may result in a call getting stuck. In the instance being seen, where AFS tries to send a probe to the Volume Location server, tracepoints show the UDP Tx failure (in this case returing error 99 EADDRNOTAVAIL) and then nothing more: afs_make_vl_call: c=0000015d VL.GetCapabilities rxrpc_call: c=0000015d NWc u=1 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000dd89ee8a rxrpc_call: c=0000015d Gus u=2 sp=rxrpc_new_client_call+0x14f/0x580 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d SEE u=2 sp=rxrpc_activate_one_channel+0x7b/0x1c0 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d CON u=2 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000e20e4b08 rxrpc_tx_fail: c=0000015d r=1 ret=-99 CallDataNofrag The problem is that if the initial packet fails and the retransmission timer hasn't been started, the call is set to completed and an error is returned from rxrpc_send_data_packet() to rxrpc_queue_packet(). Though rxrpc_instant_resend() is called, this does nothing because the call is marked completed. So rxrpc_notify_socket() isn't called and the error is passed back up to rxrpc_send_data(), rxrpc_kernel_send_data() and thence to afs_make_call() and afs_vl_get_capabilities() where it is simply ignored because it is assumed that the result of a probe will be collected asynchronously. Fileserver probing is similarly affected via afs_fs_get_capabilities(). Fix this by always issuing a notification in __rxrpc_set_call_completion() if it shifts a call to the completed state, even if an error is also returned to the caller through the function return value. Also put in a little bit of optimisation to avoid taking the call state_lock and disabling softirqs if the call is already in the completed state and remove some now redundant rxrpc_notify_socket() calls. Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Reported-by: Gerry Seidman <gerry@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
2020-06-05rxrpc: Move the call completion handling out of lineDavid Howells1-0/+74
Move the handling of call completion out of line so that the next patch can add more code in that area. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
2019-10-31rxrpc: Fix handling of last subpacket of jumbo packetDavid Howells1-5/+13
When rxrpc_recvmsg_data() sets the return value to 1 because it's drained all the data for the last packet, it checks the last-packet flag on the whole packet - but this is wrong, since the last-packet flag is only set on the final subpacket of the last jumbo packet. This means that a call that receives its last packet in a jumbo packet won't complete properly. Fix this by having rxrpc_locate_data() determine the last-packet state of the subpacket it's looking at and passing that back to the caller rather than having the caller look in the packet header. The caller then needs to cache this in the rxrpc_call struct as rxrpc_locate_data() isn't then called again for this packet. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Fixes: e2de6c404898 ("rxrpc: Use info in skbuff instead of reparsing a jumbo packet") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-07rxrpc: Fix call crypto state cleanupDavid Howells1-3/+3
Fix the cleanup of the crypto state on a call after the call has been disconnected. As the call has been disconnected, its connection ref has been discarded and so we can't go through that to get to the security ops table. Fix this by caching the security ops pointer in the rxrpc_call struct and using that when freeing the call security state. Also use this in other places we're dealing with call-specific security. The symptoms look like: BUG: KASAN: use-after-free in rxrpc_release_call+0xb2d/0xb60 net/rxrpc/call_object.c:481 Read of size 8 at addr ffff888062ffeb50 by task syz-executor.5/4764 Fixes: 1db88c534371 ("rxrpc: Fix -Wframe-larger-than= warnings from on-stack crypto") Reported-by: syzbot+eed305768ece6682bb7f@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com>
2019-08-27rxrpc: Use the tx-phase skb flag to simplify tracingDavid Howells1-3/+3
Use the previously-added transmit-phase skbuff private flag to simplify the socket buffer tracing a bit. Which phase the skbuff comes from can now be divined from the skb rather than having to be guessed from the call state. We can also reduce the number of rxrpc_skb_trace values by eliminating the difference between Tx and Rx in the symbols. Signed-off-by: David Howells <dhowells@redhat.com>