kernel/linux.git/drivers/net/xen-netback, branch v6.12.80

xen-netback: reject zero-queue configuration from guest

2026-03-04T12:20:37+00:00

[ Upstream commit 6d1dc8014334c7fb25719999bca84d811e60a559 ] A malicious or buggy Xen guest can write "0" to the xenbus key "multi-queue-num-queues". The connect() function in the backend only validates the upper bound (requested_num_queues > xenvif_max_queues) but not zero, allowing requested_num_queues=0 to reach vzalloc(array_size(0, sizeof(struct xenvif_queue))), which triggers WARN_ON_ONCE(!size) in __vmalloc_node_range(). On systems with panic_on_warn=1, this allows a guest-to-host denial of service. The Xen network interface specification requires the queue count to be "greater than zero". Add a zero check to match the validation already present in xen-blkback, which has included this guard since its multi-queue support was added. Fixes: 8d3d53b3e433 ("xen-netback: Add support for multiple queues") Signed-off-by: Ziyi Guo Reviewed-by: Juergen Gross Link: https://patch.msgid.link/20260212224040.86674-1-n7l8m4@u.northwestern.edu Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/xen-netback: prevent UAF in xenvif_flush_hash()

2024-08-29T00:07:42+00:00

During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe. Signed-off-by: Jeongjun Park Link: https://patch.msgid.link/20240822181109.2577354-1-aha310510@gmail.com Signed-off-by: Jakub Kicinski

net: annotate writes on dev->mtu from ndo_change_mtu()

2024-05-07T23:19:14+00:00

Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller Reviewed-by: Sabrina Dubroca Reviewed-by: Simon Horman Acked-by: Shannon Nelson Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski

Merge branch 'for-uring-ubufops' into HEAD

2024-04-23T00:15:39+00:00

Pavel Begunkov says: ==================== implement io_uring notification (ubuf_info) stacking (net part) To have per request buffer notifications each zerocopy io_uring send request allocates a new ubuf_info. However, as an skb can carry only one uarg, it may force the stack to create many small skbs hurting performance in many ways. The patchset implements notification, i.e. an io_uring's ubuf_info extension, stacking. It attempts to link ubuf_info's into a list, allowing to have multiple of them per skb. liburing/examples/send-zerocopy shows up 6 times performance improvement for TCP with 4KB bytes per send, and levels it with MSG_ZEROCOPY. Without the patchset it requires much larger sends to utilise all potential. bytes | before | after (Kqps) 1200 | 195 | 1023 4000 | 193 | 1386 8000 | 154 | 1058 ==================== Link: https://lore.kernel.org/all/cover.1713369317.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski

net: extend ubuf_info callback to ops structure

2024-04-22T23:21:35+00:00

We'll need to associate additional callbacks with ubuf_info, introduce a structure holding ubuf_info callbacks. Apart from a more smarter io_uring notification management introduced in next patches, it can be used to generalise msg_zerocopy_put_abort() and also store ->sg_from_iter, which is currently passed in struct msghdr. Reviewed-by: Jens Axboe Reviewed-by: David Ahern Signed-off-by: Pavel Begunkov Reviewed-by: Willem de Bruijn Link: https://lore.kernel.org/all/a62015541de49c0e2a8a0377a1d5d0a5aeb07016.1713369317.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski

net: move skb ref helpers to new header

2024-04-12T02:29:22+00:00

Add a new header, linux/skbuff_ref.h, which contains all the skb_*_ref() helpers. Many of the consumers of skbuff.h do not actually use any of the skb ref helpers, and we can speed up compilation a bit by minimizing this header file. Additionally in the later patch in the series we add page_pool support to skb_frag_ref(), which requires some page_pool dependencies. We can now add these dependencies to skbuff_ref.h instead of a very ubiquitous skbuff.h Signed-off-by: Mina Almasry Link: https://lore.kernel.org/r/20240410190505.1225848-2-almasrymina@google.com Signed-off-by: Jakub Kicinski

net: fill in MODULE_DESCRIPTION()s for xen-netback

2024-02-15T16:03:45+00:00

W=1 builds now warn if module is built without a MODULE_DESCRIPTION(). Add descriptions to the Xen backend network module. Signed-off-by: Breno Leitao Acked-by: Paul Durrant Link: https://lore.kernel.org/r/20240214152741.670178-2-leitao@debian.org Signed-off-by: Jakub Kicinski

xen-netback: properly sync TX responses

2024-02-01T16:29:36+00:00

Invoking the make_tx_response() / push_tx_responses() pair with no lock held would be acceptable only if all such invocations happened from the same context (NAPI instance or dealloc thread). Since this isn't the case, and since the interface "spec" also doesn't demand that multicast operations may only be performed with no in-flight transmits, MCAST_{ADD,DEL} processing also needs to acquire the response lock around the invocations. To prevent similar mistakes going forward, "downgrade" the present functions to private helpers of just the two remaining ones using them directly, with no forward declarations anymore. This involves renaming what so far was make_tx_response(), for the new function of that name to serve the new (wrapper) purpose. While there, - constify the txp parameters, - correct xenvif_idx_release()'s status parameter's type, - rename {,_}make_tx_response()'s status parameters for consistency with xenvif_idx_release()'s. Fixes: 210c34dcd8d9 ("xen-netback: add support for multicast control") Cc: stable@vger.kernel.org Signed-off-by: Jan Beulich Reviewed-by: Paul Durrant Link: https://lore.kernel.org/r/980c6c3d-e10e-4459-8565-e8fbde122f00@suse.com Signed-off-by: Jakub Kicinski

xen-netback: don't produce zero-size SKB frags

2024-01-08T06:41:39+00:00

While frontends may submit zero-size requests (wasting a precious slot), core networking code as of at least 3ece782693c4b ("sock: skb_copy_ubufs support for compound pages") can't deal with SKBs when they have all zero-size fragments. Respond to empty requests right when populating fragments; all further processing is fragment based and hence won't encounter these empty requests anymore. In a way this should have been that way from the beginning: When no data is to be transferred for a particular request, there's not even a point in validating the respective grant ref. That's no different from e.g. passing NULL into memcpy() when at the same time the size is 0. This is XSA-448 / CVE-2023-46838. Cc: stable@vger.kernel.org Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Reviewed-by: Paul Durrant

Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-11-03T06:53:31+00:00

Pull non-MM updates from Andrew Morton: "As usual, lots of singleton and doubleton patches all over the tree and there's little I can say which isn't in the individual changelogs. The lengthier patch series are - 'kdump: use generic functions to simplify crashkernel reservation in arch', from Baoquan He. This is mainly cleanups and consolidation of the 'crashkernel=' kernel parameter handling - After much discussion, David Laight's 'minmax: Relax type checks in min() and max()' is here. Hopefully reduces some typecasting and the use of min_t() and max_t() - A group of patches from Oleg Nesterov which clean up and slightly fix our handling of reads from /proc/PID/task/... and which remove task_struct.thread_group" * tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits) scripts/gdb/vmalloc: disable on no-MMU scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n .mailmap: add address mapping for Tomeu Vizoso mailmap: update email address for Claudiu Beznea tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions .mailmap: map Benjamin Poirier's address scripts/gdb: add lx_current support for riscv ocfs2: fix a spelling typo in comment proc: test ProtectionKey in proc-empty-vm test proc: fix proc-empty-vm test with vsyscall fs/proc/base.c: remove unneeded semicolon do_io_accounting: use sig->stats_lock do_io_accounting: use __for_each_thread() ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error() ocfs2: fix a typo in a comment scripts/show_delta: add __main__ judgement before main code treewide: mark stuff as __ro_after_init fs: ocfs2: check status values proc: test /proc/${pid}/statm compiler.h: move __is_constexpr() to compiler.h ...