user/sven/linux.git/include, branch v6.8.1

x86/rfds: Mitigate Register File Data Sampling (RFDS)

2024-03-15T14:48:13Z

commit 8076fcde016c9c0e0660543e67bff86cb48a7c9c upstream. RFDS is a CPU vulnerability that may allow userspace to infer kernel stale data previously used in floating point registers, vector registers and integer registers. RFDS only affects certain Intel Atom processors. Intel released a microcode update that uses VERW instruction to clear the affected CPU buffers. Unlike MDS, none of the affected cores support SMT. Add RFDS bug infrastructure and enable the VERW based mitigation by default, that clears the affected buffers just before exiting to userspace. Also add sysfs reporting and cmdline parameter "reg_file_data_sampling" to control the mitigation. For details see: Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst Signed-off-by: Pawan Gupta Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Acked-by: Josh Poimboeuf Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2024-03-10T18:53:21Z

Pull tracing fixes from Steven Rostedt: - Do not allow large strings (> 4096) as single write to trace_marker The size of a string written into trace_marker was determined by the size of the sub-buffer in the ring buffer. That size is dependent on the PAGE_SIZE of the architecture as it can be mapped into user space. But on PowerPC, where PAGE_SIZE is 64K, that made the limit of the string of writing into trace_marker 64K. One of the selftests looks at the size of the ring buffer sub-buffers and writes that plus more into the trace_marker. The write will take what it can and report back what it consumed so that the user space application (like echo) will write the rest of the string. The string is stored in the ring buffer and can be read via the "trace" or "trace_pipe" files. The reading of the ring buffer uses vsnprintf(), which uses a precision "%.*s" to make sure it only reads what is stored in the buffer, as a bug could cause the string to be non terminated. With the combination of the precision change and the PAGE_SIZE of 64K allowing huge strings to be added into the ring buffer, plus the test that would actually stress that limit, a bug was reported that the precision used was too big for "%.*s" as the string was close to 64K in size and the max precision of vsnprintf is 32K. Linus suggested not to have that precision as it could hide a bug if the string was again stored without a nul byte. Another issue that was brought up is that the trace_seq buffer is also based on PAGE_SIZE even though it is not tied to the architecture limit like the ring buffer sub-buffer is. Having it be 64K * 2 is simply just too big and wasting memory on systems with 64K page sizes. It is now hardcoded to 8K which is what all other architectures with 4K PAGE_SIZE has. Finally, the write to trace_marker is now limited to 4K as there is no reason to write larger strings into trace_marker. - ring_buffer_wait() should not loop. The ring_buffer_wait() does not have the full context (yet) on if it should loop or not. Just exit the loop as soon as its woken up and let the callers decide to loop or not (they already do, so it's a bit redundant). - Fix shortest_full field to be the smallest amount in the ring buffer that a waiter is waiting for. The "shortest_full" field is updated when a new waiter comes in and wants to wait for a smaller amount of data in the ring buffer than other waiters. But after all waiters are woken up, it's not reset, so if another waiter comes in wanting to wait for more data, it will be woken up when the ring buffer has a smaller amount from what the previous waiters were waiting for. - The wake up all waiters on close is incorrectly called frome .release() and not from .flush() so it will never wake up any waiters as the .release() will not get called until all .read() calls are finished. And the wakeup is for the waiters in those .read() calls. * tag 'trace-ring-buffer-v6.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use .flush() call to wake up readers ring-buffer: Fix resetting of shortest_full ring-buffer: Fix waking up ring buffer readers tracing: Limit trace_marker writes to just 4K tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE tracing: Remove precision vsnprintf() check from print event

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2024-03-10T16:27:39Z

Pull kvm fixes from Paolo Bonzini: "KVM GUEST_MEMFD fixes for 6.8: - Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY to avoid creating an inconsistent ABI (KVM_MEM_GUEST_MEMFD is not writable from userspace, so there would be no way to write to a read-only guest_memfd). - Update documentation for KVM_SW_PROTECTED_VM to make it abundantly clear that such VMs are purely for development and testing. - Limit KVM_SW_PROTECTED_VM guests to the TDP MMU, as the long term plan is to support confidential VMs with deterministic private memory (SNP and TDX) only in the TDP MMU. - Fix a bug in a GUEST_MEMFD dirty logging test that caused false passes. x86 fixes: - Fix missing marking of a guest page as dirty when emulating an atomic access. - Check for mmu_notifier invalidation events before faulting in the pfn, and before acquiring mmu_lock, to avoid unnecessary work and lock contention with preemptible kernels (including CONFIG_PREEMPT_DYNAMIC in non-preemptible mode). - Disable AMD DebugSwap by default, it breaks VMSA signing and will be re-enabled with a better VM creation API in 6.10. - Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock, to avoid a race with unregistering of the same region and the consequent use-after-free issue" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: SEV: disable SEV-ES DebugSwap by default KVM: x86/mmu: Retry fault before acquiring mmu_lock if mapping is changing KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() KVM: selftests: Add a testcase to verify GUEST_MEMFD and READONLY are exclusive KVM: selftests: Create GUEST_MEMFD for relevant invalid flags testcases KVM: x86/mmu: Restrict KVM_SW_PROTECTED_VM to the TDP MMU KVM: x86: Update KVM_SW_PROTECTED_VM docs to make it clear they're a WIP KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY KVM: x86: Mark target gfn of emulated atomic instruction as dirty

Merge tag 'mm-hotfixes-stable-2024-03-07-16-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-03-08T01:16:38Z

Pull misc fixes from Andrew Morton: "6 hotfixes. 4 are cc:stable and the remainder pertain to post-6.7 issues or aren't considered to be needed in earlier kernel versions" * tag 'mm-hotfixes-stable-2024-03-07-16-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: scripts/gdb/symbols: fix invalid escape sequence warning mailmap: fix Kishon's email init/Kconfig: lower GCC version check for -Warray-bounds mm, mmap: fix vma_merge() case 7 with vma_ops->close mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations

Merge tag 'net-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-03-07T17:23:33Z

Pull networking fixes from Paolo Abeni: "Including fixes from bpf, ipsec and netfilter. No solution yet for the stmmac issue mentioned in the last PR, but it proved to be a lockdep false positive, not a blocker. Current release - regressions: - dpll: move all dpll<>netdev helpers to dpll code, fix build regression with old compilers Current release - new code bugs: - page_pool: fix netlink dump stop/resume Previous releases - regressions: - bpf: fix verifier to check bpf_func_state->callback_depth when pruning states as otherwise unsafe programs could get accepted - ipv6: avoid possible UAF in ip6_route_mpath_notify() - ice: reconfig host after changing MSI-X on VF - mlx5: - e-switch, change flow rule destination checking - add a memory barrier to prevent a possible null-ptr-deref - switch to using _bh variant of of spinlock where needed Previous releases - always broken: - netfilter: nf_conntrack_h323: add protection for bmp length out of range - bpf: fix to zero-initialise xdp_rxq_info struct before running XDP program in CPU map which led to random xdp_md fields - xfrm: fix UDP encapsulation in TX packet offload - netrom: fix data-races around sysctls - ice: - fix potential NULL pointer dereference in ice_bridge_setlink() - fix uninitialized dplls mutex usage - igc: avoid returning frame twice in XDP_REDIRECT - i40e: disable NAPI right after disabling irqs when handling xsk_pool - geneve: make sure to pull inner header in geneve_rx() - sparx5: fix use after free inside sparx5_del_mact_entry - dsa: microchip: fix register write order in ksz8_ind_write8() Misc: - selftests: mptcp: fixes for diag.sh" * tag 'net-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (63 commits) net: pds_core: Fix possible double free in error handling path netrom: Fix data-races around sysctl_net_busy_read netrom: Fix a data-race around sysctl_netrom_link_fails_count netrom: Fix a data-race around sysctl_netrom_routing_control netrom: Fix a data-race around sysctl_netrom_transport_no_activity_timeout netrom: Fix a data-race around sysctl_netrom_transport_requested_window_size netrom: Fix a data-race around sysctl_netrom_transport_busy_delay netrom: Fix a data-race around sysctl_netrom_transport_acknowledge_delay netrom: Fix a data-race around sysctl_netrom_transport_maximum_tries netrom: Fix a data-race around sysctl_netrom_transport_timeout netrom: Fix data-races around sysctl_netrom_network_ttl_initialiser netrom: Fix a data-race around sysctl_netrom_obsolescence_count_initialiser netrom: Fix a data-race around sysctl_netrom_default_path_quality netfilter: nf_conntrack_h323: Add protection for bmp length out of range netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout netfilter: nft_ct: fix l3num expectations with inet pseudo family netfilter: nf_tables: reject constant set with timeout netfilter: nf_tables: disallow anonymous set with timeout flag net/rds: fix WARNING in rds_conn_connect_if_down net: dsa: microchip: fix register write order in ksz8_ind_write8() ...

tracing: Limit trace_seq size to just 8K and not depend on architecture PAGE_SIZE

2024-03-06T18:27:00Z

The trace_seq buffer is used to print out entire events. It's typically set to PAGE_SIZE * 2 as there's some events that can be quite large. As a side effect, writes to trace_marker is limited by both the size of the trace_seq buffer as well as the ring buffer's sub-buffer size (which is a power of PAGE_SIZE). By limiting the trace_seq size, it also limits the size of the largest string written to trace_marker. trace_seq does not need to be dependent on PAGE_SIZE like the ring buffer sub-buffers need to be. Hard code it to 8K which is PAGE_SIZE * 2 on most architectures. This will also limit the size of trace_marker on those architectures with greater than 4K PAGE_SIZE. Link: https://lore.kernel.org/all/20240302111244.3a1674be@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20240304191342.56fb1087@gandalf.local.home Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Linus Torvalds Cc: Sachin Sant Signed-off-by: Steven Rostedt (Google)

Merge tag 'vfs-6.8-release.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-03-06T16:12:27Z

Pull vfs fixes from Christian Brauner: - Get rid of copy_mc flag in iov_iter which really only makes sense for the core dumping code so move it out of the generic iov iter code and make it coredump's problem. See the detailed commit description. - Revert fs/aio: Make io_cancel() generate completions again The initial fix here was predicated on the assumption that calling ki_cancel() didn't complete aio requests. However, that turned out to be wrong since the two drivers that actually make use of this set a cancellation function that performs the cancellation correctly. So revert this change. - Ensure that the test for IOCB_AIO_RW always happens before the read from ki_ctx. * tag 'vfs-6.8-release.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: iov_iter: get rid of 'copy_mc' flag fs/aio: Check IOCB_AIO_RW before the struct aio_kiocb conversion Revert "fs/aio: Make io_cancel() generate completions again"

iov_iter: get rid of 'copy_mc' flag

2024-03-06T09:52:12Z

This flag is only set by one single user: the magical core dumping code that looks up user pages one by one, and then writes them out using their kernel addresses (by using a BVEC_ITER). That actually ends up being a huge problem, because while we do use copy_mc_to_kernel() for this case and it is able to handle the possible machine checks involved, nothing else is really ready to handle the failures caused by the machine check. In particular, as reported by Tong Tiangen, we don't actually support fault_in_iov_iter_readable() on a machine check area. As a result, the usual logic for writing things to a file under a filesystem lock, which involves doing a copy with page faults disabled and then if that fails trying to fault pages in without holding the locks with fault_in_iov_iter_readable() does not work at all. We could decide to always just make the MC copy "succeed" (and filling the destination with zeroes), and that would then create a core dump file that just ignores any machine checks. But honestly, this single special case has been problematic before, and means that all the normal iov_iter code ends up slightly more complex and slower. See for example commit c9eec08bac96 ("iov_iter: Don't deal with iter->copy_mc in memcpy_from_iter_mc()") where David Howells re-organized the code just to avoid having to check the 'copy_mc' flags inside the inner iov_iter loops. So considering that we have exactly one user, and that one user is a non-critical special case that doesn't actually ever trigger in real life (Tong found this with manual error injection), the sane solution is to just decide that the onus on handling the machine check lines on that user instead. Ergo, do the copy_mc_to_kernel() in the core dump logic itself, copying the user data to a stable kernel page before writing it out. Fixes: f1982740f5e7 ("iov_iter: Convert iterate*() to inline funcs") Signed-off-by: Linus Torvalds Signed-off-by: Tong Tiangen Link: https://lore.kernel.org/r/20240305133336.3804360-1-tongtiangen@huawei.com Link: https://lore.kernel.org/all/4e80924d-9c85-f13a-722a-6a5d2b1c225a@huawei.com/ Tested-by: David Howells Reviewed-by: David Howells Reviewed-by: Jens Axboe Reported-by: Tong Tiangen Signed-off-by: Christian Brauner

dpll: move all dpll<>netdev helpers to dpll code

2024-03-06T02:36:42Z

Older versions of GCC really want to know the full definition of the type involved in rcu_assign_pointer(). struct dpll_pin is defined in a local header, net/core can't reach it. Move all the netdev <> dpll code into dpll, where the type is known. Otherwise we'd need multiple function calls to jump between the compilation units. This is the same problem the commit under fixes was trying to address, but with rcu_assign_pointer() not rcu_dereference(). Some of the exports are not needed, networking core can't be a module, we only need exports for the helpers used by drivers. Reported-by: Geert Uytterhoeven Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/ Fixes: 640f41ed33b5 ("dpll: fix build failure due to rcu_dereference_check() on unknown type") Reviewed-by: Jiri Pirko Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

Merge tag 'hyperv-fixes-signed-20240303' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2024-03-05T20:38:50Z

Pull hyperv fixes from Wei Liu: - Multiple fixes, cleanups and documentations for Hyper-V core code and drivers * tag 'hyperv-fixes-signed-20240303' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: make hv_bus const x86/hyperv: Allow 15-bit APIC IDs for VTL platforms x86/hyperv: Make encrypted/decrypted changes safe for load_unaligned_zeropad() x86/mm: Regularize set_memory_p() parameters and make non-static x86/hyperv: Use slow_virt_to_phys() in page transition hypervisor callback Documentation: hyperv: Add overview of PCI pass-thru device support Drivers: hv: vmbus: Update indentation in create_gpadl_header() Drivers: hv: vmbus: Remove duplication and cleanup code in create_gpadl_header() fbdev/hyperv_fb: Fix logic error for Gen2 VMs in hvfb_getmem() Drivers: hv: vmbus: Calculate ring buffer size for more efficient use of memory hv_utils: Allow implicit ICTIMESYNCFLAG_SYNC