kernel/linux.git/include/linux, branch v5.7.4

x86/{mce,mm}: Unmap the entire page if the whole page is affected and poisoned

2020-06-17T14:42:56+00:00

commit 17fae1294ad9d711b2c3dd0edef479d40c76a5e8 upstream. An interesting thing happened when a guest Linux instance took a machine check. The VMM unmapped the bad page from guest physical space and passed the machine check to the guest. Linux took all the normal actions to offline the page from the process that was using it. But then guest Linux crashed because it said there was a second machine check inside the kernel with this stack trace: do_memory_failure set_mce_nospec set_memory_uc _set_memory_uc change_page_attr_set_clr cpa_flush clflush_cache_range_opt This was odd, because a CLFLUSH instruction shouldn't raise a machine check (it isn't consuming the data). Further investigation showed that the VMM had passed in another machine check because is appeared that the guest was accessing the bad page. Fix is to check the scope of the poison by checking the MCi_MISC register. If the entire page is affected, then unmap the page. If only part of the page is affected, then mark the page as uncacheable. This assumes that VMMs will do the logical thing and pass in the "whole page scope" via the MCi_MISC register (since they unmapped the entire page). [ bp: Adjust to x86/entry changes. ] Fixes: 284ce4011ba6 ("x86/memory_failure: Introduce {set, clear}_mce_nospec()") Reported-by: Jue Wang Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Tested-by: Jue Wang Cc: Link: https://lkml.kernel.org/r/20200520163546.GA7977@agluck-desk2.amr.corp.intel.com Signed-off-by: Greg Kroah-Hartman

KVM: x86: Fix APIC page invalidation race

2020-06-17T14:42:50+00:00

commit e649b3f0188f8fd34dd0dde8d43fd3312b902fb2 upstream. Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86: mm: ptdump: calculate effective permissions correctly

2020-06-17T14:42:48+00:00

commit 1494e0c38ee903e83aefb58caf54a9217273d49a upstream. Patch series "Fix W+X debug feature on x86" Jan alerted me[1] that the W+X detection debug feature was broken in x86 by my change[2] to switch x86 to use the generic ptdump infrastructure. Fundamentally the approach of trying to move the calculation of effective permissions into note_page() was broken because note_page() is only called for 'leaf' entries and the effective permissions are passed down via the internal nodes of the page tree. The solution I've taken here is to create a new (optional) callback which is called for all nodes of the page tree and therefore can calculate the effective permissions. Secondly on some configurations (32 bit with PAE) "unsigned long" is not large enough to store the table entries. The fix here is simple - let's just use a u64. [1] https://lore.kernel.org/lkml/d573dc7e-e742-84de-473d-f971142fa319@suse.com/ [2] 2ae27137b2db ("x86: mm: convert dump_pagetables to use walk_page_range") This patch (of 2): By switching the x86 page table dump code to use the generic code the effective permissions are no longer calculated correctly because the note_page() function is only called for *leaf* entries. To calculate the actual effective permissions it is necessary to observe the full hierarchy of the page tree. Introduce a new callback for ptdump which is called for every entry and can therefore update the prot_levels array correctly. note_page() can then simply access the appropriate element in the array. [steven.price@arm.com: make the assignment conditional on val != 0] Link: http://lkml.kernel.org/r/430c8ab4-e7cd-6933-dde6-087fac6db872@arm.com Fixes: 2ae27137b2db ("x86: mm: convert dump_pagetables to use walk_page_range") Reported-by: Jan Beulich Signed-off-by: Steven Price Signed-off-by: Andrew Morton Cc: Qian Cai Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Link: http://lkml.kernel.org/r/20200521152308.33096-1-steven.price@arm.com Link: http://lkml.kernel.org/r/20200521152308.33096-2-steven.price@arm.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

padata: add separate cpuhp node for CPUHP_PADATA_DEAD

2020-06-17T14:42:47+00:00

[ Upstream commit 3c2214b6027ff37945799de717c417212e1a8c54 ] Removing the pcrypt module triggers this: general protection fault, probably for non-canonical address 0xdead000000000122 CPU: 5 PID: 264 Comm: modprobe Not tainted 5.6.0+ #2 Hardware name: QEMU Standard PC RIP: 0010:__cpuhp_state_remove_instance+0xcc/0x120 Call Trace: padata_sysfs_release+0x74/0xce kobject_put+0x81/0xd0 padata_free+0x12/0x20 pcrypt_exit+0x43/0x8ee [pcrypt] padata instances wrongly use the same hlist node for the online and dead states, so __padata_free()'s second cpuhp remove call chokes on the node that the first poisoned. cpuhp multi-instance callbacks only walk forward in cpuhp_step->list and the same node is linked in both the online and dead lists, so the list corruption that results from padata_alloc() adding the node to a second list without removing it from the first doesn't cause problems as long as no instances are freed. Avoid the issue by giving each state its own node. Fixes: 894c9ef9780c ("padata: validate cpumask without removed CPU during offline") Signed-off-by: Daniel Jordan Cc: Herbert Xu Cc: Steffen Klassert Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin

mm: add kvfree_sensitive() for freeing sensitive data objects

2020-06-17T14:42:45+00:00

[ Upstream commit d4eaa2837851db2bfed572898bfc17f9a9f9151e ] For kvmalloc'ed data object that contains sensitive information like cryptographic keys, we need to make sure that the buffer is always cleared before freeing it. Using memset() alone for buffer clearing may not provide certainty as the compiler may compile it away. To be sure, the special memzero_explicit() has to be used. This patch introduces a new kvfree_sensitive() for freeing those sensitive data objects allocated by kvmalloc(). The relevant places where kvfree_sensitive() can be used are modified to use it. Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read") Suggested-by: Linus Torvalds Signed-off-by: Waiman Long Signed-off-by: Andrew Morton Reviewed-by: Eric Biggers Acked-by: David Howells Cc: Jarkko Sakkinen Cc: James Morris Cc: "Serge E. Hallyn" Cc: Joe Perches Cc: Matthew Wilcox Cc: David Rientjes Cc: Uladzislau Rezki Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

elfnote: mark all .note sections SHF_ALLOC

2020-06-17T14:42:44+00:00

commit 51da9dfb7f20911ae4e79e9b412a9c2d4c373d4b upstream. ELFNOTE_START allows callers to specify flags for .pushsection assembler directives. All callsites but ELF_NOTE use "a" for SHF_ALLOC. For vdso's that explicitly use ELF_NOTE_START and BUILD_SALT, the same section is specified twice after preprocessing, once with "a" flag, once without. Example: .pushsection .note.Linux, "a", @note ; .pushsection .note.Linux, "", @note ; While GNU as allows this ordering, it warns for the opposite ordering, making these directives position dependent. We'd prefer not to precisely match this behavior in Clang's integrated assembler. Instead, the non __ASSEMBLY__ definition of ELF_NOTE uses __attribute__((section(".note.Linux"))) which is created with SHF_ALLOC, so let's make the __ASSEMBLY__ definition of ELF_NOTE consistent with C and just always use "a" flag. This allows Clang to assemble a working mainline (5.6) kernel via: $ make CC=clang AS=clang Signed-off-by: Nick Desaulniers Signed-off-by: Andrew Morton Reviewed-by: Nathan Chancellor Reviewed-by: Fangrui Song Cc: Jeremy Fitzhardinge Cc: Thomas Gleixner Cc: Vincenzo Frascino Link: https://github.com/ClangBuiltLinux/linux/issues/913 Link: http://lkml.kernel.org/r/20200325231250.99205-1-ndesaulniers@google.com Debugged-by: Ilie Halip Signed-off-by: Linus Torvalds Cc: Jian Cai Signed-off-by: Greg Kroah-Hartman

x86/cpu: Add a steppings field to struct x86_cpu_id

2020-06-10T18:21:44+00:00

commit e9d7144597b10ff13ff2264c059f7d4a7fbc89ac upstream Intel uses the same family/model for several CPUs. Sometimes the stepping must be checked to tell them apart. On x86 there can be at most 16 steppings. Add a steppings bitmask to x86_cpu_id and a X86_MATCH_VENDOR_FAMILY_MODEL_STEPPING_FEATURE macro and support for matching against family/model/stepping. [ bp: Massage. ] Signed-off-by: Mark Gross Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Tony Luck Reviewed-by: Josh Poimboeuf Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2020-05-31T17:16:53+00:00

Pull networking fixes from David Miller: "Another week, another set of bug fixes: 1) Fix pskb_pull length in __xfrm_transport_prep(), from Xin Long. 2) Fix double xfrm_state put in esp{4,6}_gro_receive(), also from Xin Long. 3) Re-arm discovery timer properly in mac80211 mesh code, from Linus Lüssing. 4) Prevent buffer overflows in nf_conntrack_pptp debug code, from Pablo Neira Ayuso. 5) Fix race in ktls code between tls_sw_recvmsg() and tls_decrypt_done(), from Vinay Kumar Yadav. 6) Fix crashes on TCP fallback in MPTCP code, from Paolo Abeni. 7) More validation is necessary of untrusted GSO packets coming from virtualization devices, from Willem de Bruijn. 8) Fix endianness of bnxt_en firmware message length accesses, from Edwin Peer. 9) Fix infinite loop in sch_fq_pie, from Davide Caratti. 10) Fix lockdep splat in DSA by setting lockless TX in netdev features for slave ports, from Vladimir Oltean. 11) Fix suspend/resume crashes in mlx5, from Mark Bloch. 12) Fix use after free in bpf fmod_ret, from Alexei Starovoitov. 13) ARP retransmit timer guard uses wrong offset, from Hongbin Liu. 14) Fix leak in inetdev_init(), from Yang Yingliang. 15) Don't try to use inet hash and unhash in l2tp code, results in crashes. From Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (77 commits) l2tp: add sk_family checks to l2tp_validate_socket l2tp: do not use inet_hash()/inet_unhash() net: qrtr: Allocate workqueue before kernel_bind mptcp: remove msk from the token container at destruction time. mptcp: fix race between MP_JOIN and close mptcp: fix unblocking connect() net/sched: act_ct: add nat mangle action only for NAT-conntrack devinet: fix memleak in inetdev_init() virtio_vsock: Fix race condition in virtio_transport_recv_pkt drivers/net/ibmvnic: Update VNIC protocol version reporting NFC: st21nfca: add missed kfree_skb() in an error path neigh: fix ARP retransmit timer guard bpf, selftests: Add a verifier test for assigning 32bit reg states to 64bit ones bpf, selftests: Verifier bounds tests need to be updated bpf: Fix a verifier issue when assigning 32bit reg states to 64bit ones bpf: Fix use-after-free in fmod_ret check net/mlx5e: replace EINVAL in mlx5e_flower_parse_meta() net/mlx5e: Fix MLX5_TC_CT dependencies net/mlx5e: Properly set default values when disabling adaptive moderation net/mlx5e: Fix arch depending casting issue in FEC ...

net: be more gentle about silly gso requests coming from user

2020-05-28T23:31:30+00:00

Recent change in virtio_net_hdr_to_skb() broke some packetdrill tests. When --mss=XXX option is set, packetdrill always provide gso_type & gso_size for its inbound packets, regardless of packet size. if (packet->tcp && packet->mss) { if (packet->ipv4) gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; else gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; gso.gso_size = packet->mss; } Since many other programs could do the same, relax virtio_net_hdr_to_skb() to no longer return an error, but instead ignore gso settings. This keeps Willem intent to make sure no malicious packet could reach gso stack. Note that TCP stack has a special logic in tcp_set_skb_tso_segs() to clear gso_size for small packets. Fixes: 6dd912f82680 ("net: check untrusted gso_size at kernel entry") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

Merge branch 'akpm' (patches from Andrew)

2020-05-28T20:04:25+00:00

Merge misc fixes from Andrew Morton: "5 fixes" * emailed patches from Andrew Morton : include/asm-generic/topology.h: guard cpumask_of_node() macro argument fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() mm: remove VM_BUG_ON(PageSlab()) from page_mapcount() mm,thp: stop leaking unreleased file pages mm/z3fold: silence kmemleak false positives of slots