- 17 Dec, 2018 40 commits
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Alexei Starovoitov authored
commit af86ca4e upstream. Detect code patterns where malicious 'speculative store bypass' can be used and sanitize such patterns. 39: (bf) r3 = r10 40: (07) r3 += -216 41: (79) r8 = *(u64 *)(r7 +0) // slow read 42: (7a) *(u64 *)(r10 -72) = 0 // verifier inserts this instruction 43: (7b) *(u64 *)(r8 +0) = r3 // this store becomes slow due to r8 44: (79) r1 = *(u64 *)(r6 +0) // cpu speculatively executes this load 45: (71) r2 = *(u8 *)(r1 +0) // speculatively arbitrary 'load byte' // is now sanitized Above code after x86 JIT becomes: e5: mov %rbp,%rdx e8: add $0xffffffffffffff28,%rdx ef: mov 0x0(%r13),%r14 f3: movq $0x0,-0x48(%rbp) fb: mov %rdx,0x0(%r14) ff: mov 0x0(%rbx),%rdi 103: movzbq 0x0(%rdi),%rsi Signed-off-by:
Alexei Starovoitov <ast@kernel.org> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 4.4: - Add verifier_env parameter to check_stack_write() - Look up stack slot_types with state->stack_slot_type[] rather than state->stack[].slot_type[] - Drop bpf_verifier_env argument to verbose() - Adjust filename, context] Signed-off-by:
Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ben Hutchings authored
Extracted from commit 31fd8581 "bpf: permits narrower load from bpf program context fields". Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by:
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Ben Hutchings authored
Extracted from commit dc503a8a "bpf/verifier: track liveness for pruning". Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by:
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Alexei Starovoitov authored
commit cedaf52693f02372010548c63b2e63228b959099 upstream. The verifier supported only 4-byte metafields in struct __sk_buff and struct xdp_md. The metafields in upcoming struct bpf_perf_event are 8-byte to match register width in struct pt_regs. Teach verifier to recognize 8-byte metafield access. The patch doesn't affect safety of sockets and xdp programs. They check for 4-byte only ctx access before these conditions are hit. Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Tom Lendacky authored
commit bc226f07 upstream. Expose the new virtualized architectural mechanism, VIRT_SSBD, for using speculative store bypass disable (SSBD) under SVM. This will allow guests to use SSBD on hardware that uses non-architectural mechanisms for enabling SSBD. [ tglx: Folded the migration fixup from Paolo Bonzini ] Signed-off-by:
Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by:
David Woodhouse <dwmw@amazon.co.uk> Signed-off-by:
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Borislav Petkov authored
commit e7c587da upstream. Intel and AMD have different CPUID bits hence for those use synthetic bits which get set on the respective vendor's in init_speculation_control(). So that debacles like what the commit message of c65732e4 ("x86/cpu: Restore CPUID_8000_0008_EBX reload") talks about don't happen anymore. Signed-off-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tested-by:
Jörg Otte <jrg.otte@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnicSigned-off-by:
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Thomas Gleixner authored
commit ccbcd267 upstream. AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care about the bit position of the SSBD bit and thus facilitate migration. Also, the sibling coordination on Family 17H CPUs can only be done on the host. Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an extra argument for the VIRT_SPEC_CTRL MSR. Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU data structure which is going to be used in later patches for the actual implementation. Signed-off-by:
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Thomas Gleixner authored
commit 15e6c22f upstream. svm_vcpu_run() invokes x86_spec_ctrl_restore_host() after VMEXIT, but before the host GS is restored. x86_spec_ctrl_restore_host() uses 'current' to determine the host SSBD state of the thread. 'current' is GS based, but host GS is not yet restored and the access causes a triple fault. Move the call after the host GS restore. Fixes: 885f82bf x86/process: Allow runtime control of Speculative Store Bypass Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
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Konrad Rzeszutek Wilk authored
commit da39556f upstream. Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various combinations of SPEC_CTRL MSR values. The handling of the MSR (to take into account the host value of SPEC_CTRL Bit(2)) is taken care of in patch: KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS Signed-off-by:
Ingo Molnar <mingo@kernel.org> [dwmw2: Handle 4.9 guest CPUID differences, rename guest_cpu_has_ibrs() → guest_cpu_has_spec_ctrl()] Signed-off-by:
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Konrad Rzeszutek Wilk authored
commit 5cf68754 upstream. A guest may modify the SPEC_CTRL MSR from the value used by the kernel. Since the kernel doesn't use IBRS, this means a value of zero is what is needed in the host. But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to the other bits as reserved so the kernel should respect the boot time SPEC_CTRL value and use that. This allows to deal with future extensions to the SPEC_CTRL interface if any at all. Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any difference as paravirt will over-write the callq *0xfff.. with the wrmsrl assembler code. Signed-off-by:
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Dan Williams authored
commit 304ec1b0 upstream. Quoting Linus: I do think that it would be a good idea to very expressly document the fact that it's not that the user access itself is unsafe. I do agree that things like "get_user()" want to be protected, but not because of any direct bugs or problems with get_user() and friends, but simply because get_user() is an excellent source of a pointer that is obviously controlled from a potentially attacking user space. So it's a prime candidate for then finding _subsequent_ accesses that can then be used to perturb the cache. __uaccess_begin_nospec() covers __get_user() and copy_from_iter() where the limit check is far away from the user pointer de-reference. In those cases a barrier_nospec() prevents speculation with a potential pointer to privileged memory. uaccess_try_nospec covers get_user_try. Suggested-by:
Linus Torvalds <torvalds@linux-foundation.org> Suggested-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
Dan Williams <dan.j.williams@intel.com> Signed-off-by:
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Dan Williams authored
commit b5c4ae4f upstream. In preparation for converting some __uaccess_begin() instances to __uacess_begin_nospec(), make sure all 'from user' uaccess paths are using the _begin(), _end() helpers rather than open-coded stac() and clac(). No functional changes. Suggested-by:
Ingo Molnar <mingo@redhat.com> Signed-off-by:
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Dan Williams authored
commit b3bbfb3f upstream. For __get_user() paths, do not allow the kernel to speculate on the value of a user controlled pointer. In addition to the 'stac' instruction for Supervisor Mode Access Protection (SMAP), a barrier_nospec() causes the access_ok() result to resolve in the pipeline before the CPU might take any speculative action on the pointer value. Given the cost of 'stac' the speculation barrier is placed after 'stac' to hopefully overlap the cost of disabling SMAP with the cost of flushing the instruction pipeline. Since __get_user is a major kernel interface that deals with user controlled pointers, the __uaccess_begin_nospec() mechanism will prevent speculative execution past an access_ok() permission check. While speculative execution past access_ok() is not enough to lead to a kernel memory leak, it is a necessary precondition. To be clear, __uaccess_begin_nospec() is addressing a class of potential problems near __get_user() usages. Note, that while the barrier_nospec() in __uaccess_begin_nospec() is used to protect __get_user(), pointer masking similar to array_index_nospec() will be used for get_user() since it incorporates a bounds check near the usage. uaccess_try_nospec provides the same mechanism for get_user_try. No functional changes. Suggested-by:
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Linus Torvalds authored
commit de9e478b upstream. In commit 11f1a4b9 ("x86: reorganize SMAP handling in user space accesses") I changed how the stac/clac instructions were generated around the user space accesses, which then made it possible to do batched accesses efficiently for user string copies etc. However, in doing so, I completely spaced out, and didn't even think about the 32-bit case. And nobody really even seemed to notice, because SMAP doesn't even exist until modern Skylake processors, and you'd have to be crazy to run 32-bit kernels on a modern CPU. Which brings us to Andy Lutomirski. He actually tested the 32-bit kernel on new hardware, and noticed that it doesn't work. My bad. The trivial fix is to add the required uaccess begin/end markers around the raw accesses in <asm/uaccess_32.h>. I feel a bit bad about this patch, just because that header file really should be cleaned up to avoid all the duplicated code in it, and this commit just expands on the problem. But this just fixes the bug without any bigger cleanup surgery. Reported-and-tested-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
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Linus Torvalds authored
commit 11f1a4b9 upstream. This reorganizes how we do the stac/clac instructions in the user access code. Instead of adding the instructions directly to the same inline asm that does the actual user level access and exception handling, add them at a higher level. This is mainly preparation for the next step, where we will expose an interface to allow users to mark several accesses together as being user space accesses, but it does already clean up some code: - the inlined trivial cases of copy_in_user() now do stac/clac just once over the accesses: they used to do one pair around the user space read, and another pair around the write-back. - the {get,put}_user_ex() macros that are used with the catch/try handling don't do any stac/clac at all, because that happens in the try/catch surrounding them. Other than those two cleanups that happened naturally from the re-organization, this should not make any difference. Yet. Signed-off-by:
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Paolo Bonzini authored
commit ecb586bd upstream. Having a paravirt indirect call in the IBRS restore path is not a good idea, since we are trying to protect from speculative execution of bogus indirect branch targets. It is also slower, so use native_wrmsrl() on the vmentry path too. Signed-off-by:
Jim Mattson <jmattson@google.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: KarimAllah Ahmed <karahmed@amazon.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Fixes: d28b387f Link: http://lkml.kernel.org/r/20180222154318.20361-2-pbonzini@redhat.comSigned-off-by:
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KarimAllah Ahmed authored
commit b2ac58f9 upstream. [ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ] ... basically doing exactly what we do for VMX: - Passthrough SPEC_CTRL to guests (if enabled in guest CPUID) - Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest actually used it. Signed-off-by:
KarimAllah Ahmed <karahmed@amazon.de> Signed-off-by:
Darren Kenny <darren.kenny@oracle.com> Reviewed-by:
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KarimAllah Ahmed authored
commit d28b387f upstream. [ Based on a patch from Ashok Raj <ashok.raj@intel.com> ] Add direct access to MSR_IA32_SPEC_CTRL for guests. This is needed for guests that will only mitigate Spectre V2 through IBRS+IBPB and will not be using a retpoline+IBPB based approach. To avoid the overhead of saving and restoring the MSR_IA32_SPEC_CTRL for guests that do not actually use the MSR, only start saving and restoring when a non-zero is written to it. No attempt is made to handle STIBP here, intentionally. Filtering STIBP may be added in a future patch, which may require trapping all writes if we don't want to pass it through directly to the guest. [dwmw2: Clean up CPUID bits, save/restore manually, handle reset] Signed-off-by:
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KarimAllah Ahmed authored
commit 28c1c9fa upstream. Intel processors use MSR_IA32_ARCH_CAPABILITIES MSR to indicate RDCL_NO (bit 0) and IBRS_ALL (bit 1). This is a read-only MSR. By default the contents will come directly from the hardware, but user-space can still override it. [dwmw2: The bit in kvm_cpuid_7_0_edx_x86_features can be unconditional] Signed-off-by:
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Ashok Raj authored
commit 15d45071 upstream. The Indirect Branch Predictor Barrier (IBPB) is an indirect branch control mechanism. It keeps earlier branches from influencing later ones. Unlike IBRS and STIBP, IBPB does not define a new mode of operation. It's a command that ensures predicted branch targets aren't used after the barrier. Although IBRS and IBPB are enumerated by the same CPUID enumeration, IBPB is very different. IBPB helps mitigate against three potential attacks: * Mitigate guests from being attacked by other guests. - This is addressed by issing IBPB when we do a guest switch. * Mitigate attacks from guest/ring3->host/ring3. These would require a IBPB during context switch in host, or after VMEXIT. The host process has two ways to mitigate - Either it can be compiled with retpoline - If its going through context switch, and has set !dumpable then there is a IBPB in that path. (Tim's patch: https://patchwork.kernel.org/patch/10192871) - The case where after a VMEXIT you return back to Qemu might make Qemu attackable from guest when Qemu isn't compiled with retpoline. There are issues reported when doing IBPB on every VMEXIT that resulted in some tsc calibration woes in guest. * Mitigate guest/ring0->host/ring0 attacks. When host kernel is using retpoline it is safe against these attacks. If host kernel isn't using retpoline we might need to do a IBPB flush on every VMEXIT. Even when using retpoline for indirect calls, in certain conditions 'ret' can use the BTB on Skylake-era CPUs. There are other mitigations available like RSB stuffing/clearing. * IBPB is issued only for SVM during svm_free_vcpu(). VMX has a vmclear and SVM doesn't. Follow discussion here: https://lkml.org/lkml/2018/1/15/146 Please refer to the following spec for more details on the enumeration and control. Refer here to get documentation about mitigations. https://software.intel.com/en-us/side-channel-security-support [peterz: rebase and changelog rewrite] [karahmed: - rebase - vmx: expose PRED_CMD if guest has it in CPUID - svm: only pass through IBPB if guest has it in CPUID - vmx: support !cpu_has_vmx_msr_bitmap()] - vmx: support nested] [dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS) PRED_CMD is a write-only MSR] Signed-off-by:
Ashok Raj <ashok.raj@intel.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Paolo Bonzini authored
commit 904e14fb upstream. Place the MSR bitmap in struct loaded_vmcs, and update it in place every time the x2apic or APICv state can change. This is rare and the loop can handle 64 MSRs per iteration, in a similar fashion as nested_vmx_prepare_msr_bitmap. This prepares for choosing, on a per-VM basis, whether to intercept the SPEC_CTRL and PRED_CMD MSRs. Suggested-by:
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Paolo Bonzini authored
commit f21f165e upstream. Group together the calls to alloc_vmcs and loaded_vmcs_init. Soon we'll also allocate an MSR bitmap there. Signed-off-by:
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Jim Mattson authored
commit de3a0021 upstream. The potential performance advantages of a vmcs02 pool have never been realized. To simplify the code, eliminate the pool. Instead, a single vmcs02 is allocated per VCPU when the VCPU enters VMX operation. Signed-off-by:
Mark Kanda <mark.kanda@oracle.com> Reviewed-by:
Ameya More <ameya.more@oracle.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:
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David Matlack authored
commit c9f04407 upstream. The host physical addresses of L1's Virtual APIC Page and Posted Interrupt descriptor are loaded into the VMCS02. The CPU may write to these pages via their host physical address while L2 is running, bypassing address-translation-based dirty tracking (e.g. EPT write protection). Mark them dirty on every exit from L2 to prevent them from getting out of sync with dirty tracking. Also mark the virtual APIC page and the posted interrupt descriptor dirty when KVM is virtualizing posted interrupt processing. Signed-off-by:
David Matlack <dmatlack@google.com> Reviewed-by:
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Radim Krčmář authored
commit d048c098 upstream. msr bitmap can be used to avoid a VM exit (interception) on guest MSR accesses. In some configurations of VMX controls, the guest can even directly access host's x2APIC MSRs. See SDM 29.5 VIRTUALIZING MSR-BASED APIC ACCESSES. L2 could read all L0's x2APIC MSRs and write TPR, EOI, and SELF_IPI. To do so, L1 would first trick KVM to disable all possible interceptions by enabling APICv features and then would turn those features off; nested_vmx_merge_msr_bitmap() only disabled interceptions, so VMX would not intercept previously enabled MSRs even though they were not safe with the new configuration. Correctly re-enabling interceptions is not enough as a second bug would still allow L1+L2 to access host's MSRs: msr bitmap was shared for all VMCSs, so L1 could trigger a race to get the desired combination of msr bitmap and VMX controls. This fix allocates a msr bitmap for every L1 VCPU, allows only safe x2APIC MSRs from L1's msr bitmap, and disables msr bitmaps if they would have to intercept everything anyway. Fixes: 3af18d9c ("KVM: nVMX: Prepare for using hardware MSR bitmap") Reported-by:
Wincy Van <fanwenyi0529@gmail.com> Reviewed-by:
Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by:
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Takashi Sakamoto authored
commit e11f0f90 upstream. Drivers can implement 'struct snd_pcm_ops.ioctl' to handle some requests from ALSA PCM core. These requests are internal purpose in kernel land. Usually common set of operations are used for it. SNDRV_PCM_IOCTL1_INFO is one of the requests. According to code comment, it has been obsoleted in the old days. We can see old releases in ftp.alsa-project.org. The command was firstly introduced in v0.5.0 release as SND_PCM_IOCTL1_INFO, to allow drivers to fill data of 'struct snd_pcm_channel_info' type. In v0.9.0 release, this was obsoleted by the other commands for ioctl(2) such as SNDRV_PCM_IOCTL_CHANNEL_INFO. This commit removes the long-abandoned command, bye. Signed-off-by:
Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Namhyung Kim authored
[ Upstream commit 70ad35db ] Maybe I'm missing something, but I don't know why it needs to copy the input buffer to psinfo->buf and then write. Instead we can write the input buffer directly. The only implementation that supports console message (i.e. ramoops) already does it for ftrace messages. For the upcoming virtio backend driver, it needs to protect psinfo->buf overwritten from console messages. If it could use ->write_buf method instead of ->write, the problem will be solved easily. Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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Pan Bian authored
[ Upstream commit 164f7e58 ] ocfs2_get_dentry() calls iput(inode) to drop the reference count of inode, and if the reference count hits 0, inode is freed. However, in this function, it then reads inode->i_generation, which may result in a use after free bug. Move the put operation later. Link: http://lkml.kernel.org/r/1543109237-110227-1-git-send-email-bianpan2016@163.com Fixes: 781f200c("ocfs2: Remove masklog ML_EXPORT.") Signed-off-by:
Pan Bian <bianpan2016@163.com> Reviewed-by:
Andrew Morton <akpm@linux-foundation.org> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <ge.changwei@h3c.com> Signed-off-by:
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Qian Cai authored
[ Upstream commit 8de456cf ] CONFIG_DEBUG_OBJECTS_RCU_HEAD does not play well with kmemleak due to recursive calls. fill_pool kmemleak_ignore make_black_object put_object __call_rcu (kernel/rcu/tree.c) debug_rcu_head_queue debug_object_activate debug_object_init fill_pool kmemleak_ignore make_black_object ... So add SLAB_NOLEAKTRACE to kmem_cache_create() to not register newly allocated debug objects at all. Link: http://lkml.kernel.org/r/20181126165343.2339-1-cai@gmx.usSigned-off-by:
Qian Cai <cai@gmx.us> Suggested-by:
Catalin Marinas <catalin.marinas@arm.com> Acked-by:
Waiman Long <longman@redhat.com> Acked-by:
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Pan Bian authored
[ Upstream commit c7d7d620 ] hfs_bmap_free() frees node via hfs_bnode_put(node). However it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees node only when it is never used. Link: http://lkml.kernel.org/r/1543053441-66942-1-git-send-email-bianpan2016@163.comSigned-off-by:
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Pan Bian authored
[ Upstream commit ce96a407 ] hfs_bmap_free() frees the node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees the node only when it is never again used. Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by:
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Larry Chen authored
[ Upstream commit e21e5744 ] ocfs2_defrag_extent may fall into deadlock. ocfs2_ioctl_move_extents ocfs2_ioctl_move_extents ocfs2_move_extents ocfs2_defrag_extent ocfs2_lock_allocators_move_extents ocfs2_reserve_clusters inode_lock GLOBAL_BITMAP_SYSTEM_INODE __ocfs2_flush_truncate_log inode_lock GLOBAL_BITMAP_SYSTEM_INODE As backtrace shows above, ocfs2_reserve_clusters() will call inode_lock against the global bitmap if local allocator has not sufficient cluters. Once global bitmap could meet the demand, ocfs2_reserve_cluster will return success with global bitmap locked. After ocfs2_reserve_cluster(), if truncate log is full, __ocfs2_flush_truncate_log() will definitely fall into deadlock because it needs to inode_lock global bitmap, which has already been locked. To fix this bug, we could remove from ocfs2_lock_allocators_move_extents() the code which intends to lock global allocator, and put the removed code after __ocfs2_flush_truncate_log(). ocfs2_lock_allocators_move_extents() is referred by 2 places, one is here, the other does not need the data allocator context, which means this patch does not affect the caller so far. Link: http://lkml.kernel.org/r/20181101071422.14470-1-lchen@suse.comSigned-off-by:
Larry Chen <lchen@suse.com> Reviewed-by:
Changwei Ge <ge.changwei@h3c.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by:
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Colin Ian King authored
[ Upstream commit 31ffa563 ] Variable 'cache' is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: warning: variable 'cache' set but not used [-Wunused-but-set-variable] Signed-off-by:
Colin Ian King <colin.king@canonical.com> Signed-off-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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NeilBrown authored
[ Upstream commit c5a94f43 ] It was observed that a process blocked indefintely in __fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP to be cleared via fscache_wait_for_deferred_lookup(). At this time, ->backing_objects was empty, which would normaly prevent __fscache_read_or_alloc_page() from getting to the point of waiting. This implies that ->backing_objects was cleared *after* __fscache_read_or_alloc_page was was entered. When an object is "killed" and then "dropped", FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is ->backing_objects cleared. This leaves a window where something else can set FSCACHE_COOKIE_LOOKING_UP and __fscache_read_or_alloc_page() can start waiting, before ->backing_objects is cleared There is some uncertainty in this analysis, but it seems to be fit the observations. Adding the wake in this patch will be handled correctly by __fscache_read_or_alloc_page(), as it checks if ->backing_objects is empty again, after waiting. Customer which reported the hang, also report that the hang cannot be reproduced with this fix. The backtrace for the blocked process looked like: PID: 29360 TASK: ffff881ff2ac0f80 CPU: 3 COMMAND: "zsh" #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache] #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache] #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs] #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs] #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs] #10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756 #11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa #12 [ffff881ff43eff18] sys_read at ffffffff811fda62 #13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e Signed-off-by:
NeilBrown <neilb@suse.com> Signed-off-by:
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Srikanth Boddepalli authored
[ Upstream commit 72791ac8 ] Add a missing header otherwise compiler warns about missed prototype: drivers/xen/xlate_mmu.c:183:5: warning: no previous prototype for 'xen_xlate_unmap_gfn_range?' [-Wmissing-prototypes] int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma, ^~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by:
Srikanth Boddepalli <boddepalli.srikanth@gmail.com> Reviewed-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by:
Joey Pabalinas <joeypabalinas@gmail.com> Signed-off-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
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Y.C. Chen authored
[ Upstream commit 30062562 ] v1: over-sample data to increase the stability with some specific monitors v2: refine to avoid infinite loop v3: remove un-necessary "volatile" declaration [airlied: fix two checkpatch warnings] Signed-off-by:
Y.C. Chen <yc_chen@aspeedtech.com> Signed-off-by:
Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/1542858988-1127-1-git-send-email-yc_chen@aspeedtech.comSigned-off-by:
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Pan Bian authored
[ Upstream commit c7589401 ] The net device ndev is freed via free_netdev when failing to register the device. The control flow then jumps to the error handling code block. ndev is used and freed again. Resulting in a use-after-free bug. Signed-off-by:
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Josh Elsasser authored
[ Upstream commit a8bf879a ] Add the two 1000BaseLX enum values to the X550's check for 1Gbps modules, allowing the core driver code to establish a link over this SFP type. This is done by the out-of-tree driver but the fix wasn't in mainline. Fixes: e23f3336 ("ixgbe: Fix 1G and 10G link stability for X550EM_x SFP+”) Fixes: 6a14ee0c ("ixgbe: Add X550 support function pointers") Signed-off-by:
Josh Elsasser <jelsasser@appneta.com> Tested-by:
Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by:
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Lorenzo Bianconi authored
[ Upstream commit 24a6d2dd ] Fix a possible NULL pointer dereference in nic_remove routine removing the nicpf module if nic_probe fails. The issue can be triggered with the following reproducer: $rmmod nicvf $rmmod nicpf [ 521.412008] Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000014 [ 521.422777] Mem abort info: [ 521.425561] ESR = 0x96000004 [ 521.428624] Exception class = DABT (current EL), IL = 32 bits [ 521.434535] SET = 0, FnV = 0 [ 521.437579] EA = 0, S1PTW = 0 [ 521.440730] Data abort info: [ 521.443603] ISV = 0, ISS = 0x00000004 [ 521.447431] CM = 0, WnR = 0 [ 521.450417] user pgtable: 4k pages, 48-bit VAs, pgdp = 0000000072a3da42 [ 521.457022] [0000000000000014] pgd=0000000000000000 [ 521.461916] Internal error: Oops: 96000004 [#1] SMP [ 521.511801] Hardware name: GIGABYTE H270-T70/MT70-HD0, BIOS T49 02/02/2018 [ 521.518664] pstate: 80400005 (Nzcv daif +PAN -UAO) [ 521.523451] pc : nic_remove+0x24/0x88 [nicpf] [ 521.527808] lr : pci_device_remove+0x48/0xd8 [ 521.532066] sp : ffff000013433cc0 [ 521.535370] x29: ffff000013433cc0 x28: ffff810f6ac50000 [ 521.540672] x27: 0000000000000000 x26: 0000000000000000 [ 521.545974] x25: 0000000056000000 x24: 0000000000000015 [ 521.551274] x23: ffff8007ff89a110 x22: ffff000001667070 [ 521.556576] x21: ffff8007ffb170b0 x20: ffff8007ffb17000 [ 521.561877] x19: 0000000000000000 x18: 0000000000000025 [ 521.567178] x17: 0000000000000000 x16: 000000000000010ffc33ff98 x8 : 0000000000000000 [ 521.593683] x7 : 0000000000000000 x6 : 0000000000000001 [ 521.598983] x5 : 0000000000000002 x4 : 0000000000000003 [ 521.604284] x3 : ffff8007ffb17184 x2 : ffff8007ffb17184 [ 521.609585] x1 : ffff000001662118 x0 : ffff000008557be0 [ 521.614887] Process rmmod (pid: 1897, stack limit = 0x00000000859535c3) [ 521.621490] Call trace: [ 521.623928] nic_remove+0x24/0x88 [nicpf] [ 521.627927] pci_device_remove+0x48/0xd8 [ 521.631847] device_release_driver_internal+0x1b0/0x248 [ 521.637062] driver_detach+0x50/0xc0 [ 521.640628] bus_remove_driver+0x60/0x100 [ 521.644627] driver_unregister+0x34/0x60 [ 521.648538] pci_unregister_driver+0x24/0xd8 [ 521.652798] nic_cleanup_module+0x14/0x111c [nicpf] [ 521.657672] __arm64_sys_delete_module+0x150/0x218 [ 521.662460] el0_svc_handler+0x94/0x110 [ 521.666287] el0_svc+0x8/0xc [ 521.669160] Code: aa1e03e0 9102c295 d503201f f9404eb3 (b9401660) Fixes: 4863dea3 ("net: Adding support for Cavium ThunderX network controller") Signed-off-by:
Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by:
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Yi Wang authored
[ Upstream commit 354cb410 ] We get the following warnings about empty statements when building with 'W=1': arch/x86/kvm/lapic.c:632:53: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] arch/x86/kvm/lapic.c:1907:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] arch/x86/kvm/lapic.c:1936:65: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] arch/x86/kvm/lapic.c:1975:44: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] Rework the debug helper macro to get rid of these warnings. Signed-off-by:
Yi Wang <wang.yi59@zte.com.cn> Signed-off-by:
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