kernel/linux.git/drivers/net/xen-netback, branch v6.6.141

xen-netback: reject zero-queue configuration from guest

2026-03-04T12:20:18+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()

2024-10-10T09:57:22+00:00

[ Upstream commit 0fa5e94a1811d68fbffa0725efe6d4ca62c03d12 ] 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 Signed-off-by: Sasha Levin

kthread: add kthread_stop_put

2024-06-12T09:12:52+00:00

[ Upstream commit 6309727ef27162deabd5c095c11af24970fba5a2 ] Add a kthread_stop_put() helper that stops a thread and puts its task struct. Use it to replace the various instances of kthread_stop() followed by put_task_struct(). Remove the kthread_stop_put() macro in usbip that is similar but doesn't return the result of kthread_stop(). [agruenba@redhat.com: fix kerneldoc comment] Link: https://lkml.kernel.org/r/20230911111730.2565537-1-agruenba@redhat.com [akpm@linux-foundation.org: document kthread_stop_put()'s argument] Link: https://lkml.kernel.org/r/20230907234048.2499820-1-agruenba@redhat.com Signed-off-by: Andreas Gruenbacher Signed-off-by: Andrew Morton Stable-dep-of: bb9025f4432f ("dma-mapping: benchmark: fix up kthread-related error handling") Signed-off-by: Sasha Levin

xen-netback: properly sync TX responses

2024-02-23T08:25:03+00:00

commit 7b55984c96ffe9e236eb9c82a2196e0b1f84990d upstream. 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 Signed-off-by: Greg Kroah-Hartman

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

2024-01-25T23:35:41+00:00

commit c7ec4f2d684e17d69bbdd7c4324db0ef5daac26a upstream. 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 Signed-off-by: Greg Kroah-Hartman

xen-netback: use default TX queue size for vifs

2023-10-08T12:53:10+00:00

Do not set netback interfaces (vifs) default TX queue size to the ring size. The TX queue size is not related to the ring size, and using the ring size (32) as the queue size can lead to packet drops. Note the TX side of the vif interface in the netback domain is the one receiving packets to be injected to the guest. Do not explicitly set the TX queue length to any value when creating the interface, and instead use the system default. Note that the queue length can also be adjusted at runtime. Fixes: f942dc2552b8 ('xen network backend driver') Signed-off-by: Roger Pau Monné Reviewed-by: Ross Lagerwall Acked-by: Wei Liu Signed-off-by: David S. Miller

xen/netback: Fix buffer overrun triggered by unusual packet

2023-08-03T07:04:08+00:00

It is possible that a guest can send a packet that contains a head + 18 slots and yet has a len <= XEN_NETBACK_TX_COPY_LEN. This causes nr_slots to underflow in xenvif_get_requests() which then causes the subsequent loop's termination condition to be wrong, causing a buffer overrun of queue->tx_map_ops. Rework the code to account for the extra frag_overflow slots. This is CVE-2023-34319 / XSA-432. Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area") Signed-off-by: Ross Lagerwall Reviewed-by: Paul Durrant Reviewed-by: Wei Liu Signed-off-by: Juergen Gross

Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2023-07-06T17:06:04+00:00

Pull asm-generic updates from Arnd Bergmann: "These are cleanups for architecture specific header files: - the comments in include/linux/syscalls.h have gone out of sync and are really pointless, so these get removed - The asm/bitsperlong.h header no longer needs to be architecture specific on modern compilers, so use a generic version for newer architectures that use new enough userspace compilers - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking, forcing the use of pointers" * tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: syscalls: Remove file path comments from headers tools arch: Remove uapi bitsperlong.h of hexagon and microblaze asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch m68k/mm: Make pfn accessors static inlines arm64: memory: Make virt_to_pfn() a static inline ARM: mm: Make virt_to_pfn() a static inline asm-generic/page.h: Make pfn accessors static inlines xen/netback: Pass (void *) to virt_to_page() netfs: Pass a pointer to virt_to_page() cifs: Pass a pointer to virt_to_page() in cifsglob cifs: Pass a pointer to virt_to_page() riscv: mm: init: Pass a pointer to virt_to_page() ARC: init: Pass a pointer to virt_to_pfn() in init m68k: Pass a pointer to virt_to_pfn() virt_to_page() fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

xen/netback: Pass (void *) to virt_to_page()

2023-05-29T09:27:08+00:00

virt_to_page() takes a virtual address as argument but the driver passes an unsigned long, which works because the target platform(s) uses polymorphic macros to calculate the page. Since many architectures implement virt_to_pfn() as a macro, this function becomes polymorphic and accepts both a (unsigned long) and a (void *). Fix this up by an explicit (void *) cast. Cc: Wei Liu Cc: Paul Durrant Cc: xen-devel@lists.xenproject.org Cc: netdev@vger.kernel.org Acked-by: Wei Liu Signed-off-by: Linus Walleij

net: introduce and use skb_frag_fill_page_desc()

2023-05-13T18:47:56+00:00

Most users use __skb_frag_set_page()/skb_frag_off_set()/ skb_frag_size_set() to fill the page desc for a skb frag. Introduce skb_frag_fill_page_desc() to do that. net/bpf/test_run.c does not call skb_frag_off_set() to set the offset, "copy_from_user(page_address(page), ...)" and 'shinfo' being part of the 'data' kzalloced in bpf_test_init() suggest that it is assuming offset to be initialized as zero, so call skb_frag_fill_page_desc() with offset being zero for this case. Also, skb_frag_set_page() is not used anymore, so remove it. Signed-off-by: Yunsheng Lin Reviewed-by: Leon Romanovsky Reviewed-by: Simon Horman Signed-off-by: David S. Miller