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2019-04-02x86/speculation: Move arch_smt_update() call to after mitigation decisionsJosh Poimboeuf1-3/+2
arch_smt_update() now has a dependency on both Spectre v2 and MDS mitigations. Move its initial call to after all the mitigation decisions have been made. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz>
2019-04-02x86/speculation/mds: Add mds=full,nosmt cmdline optionJosh Poimboeuf3-2/+17
Add the mds=full,nosmt cmdline option. This is like mds=full, but with SMT disabled if the CPU is vulnerable. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz>
2019-03-06Documentation: Add MDS vulnerability documentationThomas Gleixner5-2/+312
Add the initial MDS vulnerability documentation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jon Masters <jcm@redhat.com>
2019-03-06Documentation: Move L1TF to separate directoryThomas Gleixner7-9/+19
Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add mitigation mode VMWERVThomas Gleixner3-6/+40
In virtualized environments it can happen that the host has the microcode update which utilizes the VERW instruction to clear CPU buffers, but the hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit to guests. Introduce an internal mitigation mode VMWERV which enables the invocation of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the system has no updated microcode this results in a pointless execution of the VERW instruction wasting a few CPU cycles. If the microcode is updated, but not exposed to a guest then the CPU buffers will be cleared. That said: Virtual Machines Will Eventually Receive Vaccine Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add sysfs reporting for MDSThomas Gleixner4-0/+36
Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add mitigation control for MDSThomas Gleixner3-0/+97
Now that the mitigations are in place, add a command line parameter to control the mitigation, a mitigation selector function and a SMT update mechanism. This is the minimal straight forward initial implementation which just provides an always on/off mode. The command line parameter is: mds=[full|off] This is consistent with the existing mitigations for other speculative hardware vulnerabilities. The idle invocation is dynamically updated according to the SMT state of the system similar to the dynamic update of the STIBP mitigation. The idle mitigation is limited to CPUs which are only affected by MSBDS and not any other variant, because the other variants cannot be mitigated on SMT enabled systems. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Conditionally clear CPU buffers on idle entryThomas Gleixner5-0/+68
Add a static key which controls the invocation of the CPU buffer clear mechanism on idle entry. This is independent of other MDS mitigations because the idle entry invocation to mitigate the potential leakage due to store buffer repartitioning is only necessary on SMT systems. Add the actual invocations to the different halt/mwait variants which covers all usage sites. mwaitx is not patched as it's not available on Intel CPUs. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU is spilled to the Hyper-Thread sibling after the Store buffer got repartitioned and all entries are available to the non idle sibling. When coming out of idle the store buffer is partitioned again so each sibling has half of it available. Now CPU which returned from idle could be speculatively exposed to contents of the sibling, but the buffers are flushed either on exit to user space or on VMENTER. When later on conditional buffer clearing is implemented on top of this, then there is no action required either because before returning to user space the context switch will set the condition flag which causes a flush on the return to user path. Note, that the buffer clearing on idle is only sensible on CPUs which are solely affected by MSBDS and not any other variant of MDS because the other MDS variants cannot be mitigated when SMT is enabled, so the buffer clearing on idle would be a window dressing exercise. This intentionally does not handle the case in the acpi/processor_idle driver which uses the legacy IO port interface for C-State transitions for two reasons: - The acpi/processor_idle driver was replaced by the intel_idle driver almost a decade ago. Anything Nehalem upwards supports it and defaults to that new driver. - The legacy IO port interface is likely to be used on older and therefore unaffected CPUs or on systems which do not receive microcode updates anymore, so there is no point in adding that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/kvm/vmx: Add MDS protection when L1D Flush is not activeThomas Gleixner2-0/+4
CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on VMENTER when updated microcode is installed. If a CPU is not affected by L1TF or if the L1D Flush is not in use, then MDS mitigation needs to be invoked explicitly. For these cases, follow the host mitigation state and invoke the MDS mitigation before VMENTER. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Clear CPU buffers on exit to userThomas Gleixner6-0/+83
Add a static key which controls the invocation of the CPU buffer clear mechanism on exit to user space and add the call into prepare_exit_to_usermode() and do_nmi() right before actually returning. Add documentation which kernel to user space transition this covers and explain why some corner cases are not mitigated. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add mds_clear_cpu_buffers()Thomas Gleixner5-0/+143
The Microarchitectural Data Sampling (MDS) vulernabilities are mitigated by clearing the affected CPU buffers. The mechanism for clearing the buffers uses the unused and obsolete VERW instruction in combination with a microcode update which triggers a CPU buffer clear when VERW is executed. Provide a inline function with the assembly magic. The argument of the VERW instruction must be a memory operand as documented: "MD_CLEAR enumerates that the memory-operand variant of VERW (for example, VERW m16) has been extended to also overwrite buffers affected by MDS. This buffer overwriting functionality is not guaranteed for the register operand variant of VERW." Documentation also recommends to use a writable data segment selector: "The buffer overwriting occurs regardless of the result of the VERW permission check, as well as when the selector is null or causes a descriptor load segment violation. However, for lowest latency we recommend using a selector that indicates a valid writable data segment." Add x86 specific documentation about MDS and the internal workings of the mitigation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/kvm: Expose X86_FEATURE_MD_CLEAR to guestsAndi Kleen1-1/+2
X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode provides the mechanism to invoke a flush of various exploitable CPU buffers by invoking the VERW instruction. Hand it through to guests so they can adjust their mitigations. This also requires corresponding qemu changes, which are available separately. [ tglx: Massaged changelog ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add BUG_MSBDS_ONLYThomas Gleixner2-8/+13
This bug bit is set on CPUs which are only affected by Microarchitectural Store Buffer Data Sampling (MSBDS) and not by any other MDS variant. This is important because the Store Buffers are partitioned between Hyper-Threads so cross thread forwarding is not possible. But if a thread enters or exits a sleep state the store buffer is repartitioned which can expose data from one thread to the other. This transition can be mitigated. That means that for CPUs which are only affected by MSBDS SMT can be enabled, if the CPU is not affected by other SMT sensitive vulnerabilities, e.g. L1TF. The XEON PHI variants fall into that category. Also the Silvermont/Airmont ATOMs, but for them it's not really relevant as they do not support SMT, but mark them for completeness sake. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation/mds: Add basic bug infrastructure for MDSAndi Kleen3-9/+23
Microarchitectural Data Sampling (MDS), is a class of side channel attacks on internal buffers in Intel CPUs. The variants are: - Microarchitectural Store Buffer Data Sampling (MSBDS) (CVE-2018-12126) - Microarchitectural Fill Buffer Data Sampling (MFBDS) (CVE-2018-12130) - Microarchitectural Load Port Data Sampling (MLPDS) (CVE-2018-12127) MSBDS leaks Store Buffer Entries which can be speculatively forwarded to a dependent load (store-to-load forwarding) as an optimization. The forward can also happen to a faulting or assisting load operation for a different memory address, which can be exploited under certain conditions. Store buffers are partitioned between Hyper-Threads so cross thread forwarding is not possible. But if a thread enters or exits a sleep state the store buffer is repartitioned which can expose data from one thread to the other. MFBDS leaks Fill Buffer Entries. Fill buffers are used internally to manage L1 miss situations and to hold data which is returned or sent in response to a memory or I/O operation. Fill buffers can forward data to a load operation and also write data to the cache. When the fill buffer is deallocated it can retain the stale data of the preceding operations which can then be forwarded to a faulting or assisting load operation, which can be exploited under certain conditions. Fill buffers are shared between Hyper-Threads so cross thread leakage is possible. MLDPS leaks Load Port Data. Load ports are used to perform load operations from memory or I/O. The received data is then forwarded to the register file or a subsequent operation. In some implementations the Load Port can contain stale data from a previous operation which can be forwarded to faulting or assisting loads under certain conditions, which again can be exploited eventually. Load ports are shared between Hyper-Threads so cross thread leakage is possible. All variants have the same mitigation for single CPU thread case (SMT off), so the kernel can treat them as one MDS issue. Add the basic infrastructure to detect if the current CPU is affected by MDS. [ tglx: Rewrote changelog ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/speculation: Consolidate CPU whitelistsThomas Gleixner1-50/+60
The CPU vulnerability whitelists have some overlap and there are more whitelists coming along. Use the driver_data field in the x86_cpu_id struct to denote the whitelisted vulnerabilities and combine all whitelists into one. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06x86/msr-index: Cleanup bit definesThomas Gleixner3-18/+20
Greg pointed out that speculation related bit defines are using (1 << N) format instead of BIT(N). Aside of that (1 << N) is wrong as it should use 1UL at least. Clean it up. [ Josh Poimboeuf: Fix tools build ] Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-03-03Linux 5.0v5.0Linus Torvalds1-1/+1
2019-03-02Merge tag 'armsoc-fixes' of ↵Linus Torvalds3-3/+5
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC fixes from Arnd Bergmann: "One more set of simple ARM platform fixes: - A boot regression on qualcomm msm8998 - Gemini display controllers got turned off by accident - incorrect reference counting in optee" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: tee: optee: add missing of_node_put after of_device_is_available arm64: dts: qcom: msm8998: Extend TZ reserved memory area ARM: dts: gemini: Re-enable display controller
2019-03-02Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2-3/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Two last minute fixes: - Prevent value evaluation via functions happening in the user access enabled region of __put_user() (put another way: make sure to evaluate the value to be stored in user space _before_ enabling user space accesses) - Correct the definition of a Hyper-V hypercall constant" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/hyper-v: Fix definition of HV_MAX_FLUSH_REP_COUNT x86/uaccess: Don't leak the AC flag into __put_user() value evaluation
2019-03-02Merge tag 'scsi-fixes' of ↵Linus Torvalds10-35/+70
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "Nine small fixes. The resume fix is a cosmetic removal of a warning with an incorrect condition causing it to alarm people wrongly. The other eight patches correct a thinko in Christoph Hellwig's DMA conversion series. Without it all these drivers end up with 32 bit DMA masks meaning they bounce any page over 4GB before sending it to the controller. Nowadays, even laptops mostly have memory above 4GB, so this can lead to significant performance degradation with all the bouncing" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: core: Avoid that system resume triggers a kernel warning scsi: hptiop: fix calls to dma_set_mask() scsi: hisi_sas: fix calls to dma_set_mask_and_coherent() scsi: csiostor: fix calls to dma_set_mask_and_coherent() scsi: bfa: fix calls to dma_set_mask_and_coherent() scsi: aic94xx: fix calls to dma_set_mask_and_coherent() scsi: 3w-sas: fix calls to dma_set_mask_and_coherent() scsi: 3w-9xxx: fix calls to dma_set_mask_and_coherent() scsi: lpfc: fix calls to dma_set_mask_and_coherent()
2019-03-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds51-106/+408
Pull networking fixes from David Miller: 1) Fix refcount leak in act_ipt during replace, from Davide Caratti. 2) Set task state properly in tun during blocking reads, from Timur Celik. 3) Leaked reference in DSA, from Wen Yang. 4) NULL deref in act_tunnel_key, from Vlad Buslov. 5) cipso_v4_erro can reference the skb IPCB in inappropriate contexts thus referencing garbage, from Nazarov Sergey. 6) Don't accept RTA_VIA and RTA_GATEWAY in contexts where those attributes make no sense. 7) Fix hung sendto in tipc, from Tung Nguyen. 8) Out-of-bounds access in netlabel, from Paul Moore. 9) Grant reference leak in xen-netback, from Igor Druzhinin. 10) Fix tx stalls with lan743x, from Bryan Whitehead. 11) Fix interrupt storm with mv88e6xxx, from Hein Kallweit. 12) Memory leak in sit on device registry failure, from Mao Wenan. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits) net: sit: fix memory leak in sit_init_net() net: dsa: mv88e6xxx: Fix statistics on mv88e6161 geneve: correctly handle ipv6.disable module parameter net: dsa: mv88e6xxx: prevent interrupt storm caused by mv88e6390x_port_set_cmode bpf: fix sanitation rewrite in case of non-pointers ipv4: Add ICMPv6 support when parse route ipproto MIPS: eBPF: Fix icache flush end address lan743x: Fix TX Stall Issue net: phy: phylink: fix uninitialized variable in phylink_get_mac_state net: aquantia: regression on cpus with high cores: set mode with 8 queues selftests: fixes for UDP GRO bpf: drop refcount if bpf_map_new_fd() fails in map_create() net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390X net: dsa: mv88e6xxx: Fix u64 statistics xen-netback: don't populate the hash cache on XenBus disconnect xen-netback: fix occasional leak of grant ref mappings under memory pressure sctp: chunk.c: correct format string for size_t in printk net: netem: fix skb length BUG_ON in __skb_to_sgvec netlabel: fix out-of-bounds memory accesses ipv4: Pass original device to ip_rcv_finish_core ...
2019-03-02Merge branch 'linus' of ↵Linus Torvalds1-2/+18
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull more crypto fixes from Herbert Xu: "This fixes a couple of issues in arm64/chacha that was introduced in 5.0" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: arm64/chacha - fix hchacha_block_neon() for big endian crypto: arm64/chacha - fix chacha_4block_xor_neon() for big endian
2019-03-02net: sit: fix memory leak in sit_init_net()Mao Wenan1-0/+1
If register_netdev() is failed to register sitn->fb_tunnel_dev, it will go to err_reg_dev and forget to free netdev(sitn->fb_tunnel_dev). BUG: memory leak unreferenced object 0xffff888378daad00 (size 512): comm "syz-executor.1", pid 4006, jiffies 4295121142 (age 16.115s) hex dump (first 32 bytes): 00 e6 ed c0 83 88 ff ff 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d6dcb63e>] kvmalloc include/linux/mm.h:577 [inline] [<00000000d6dcb63e>] kvzalloc include/linux/mm.h:585 [inline] [<00000000d6dcb63e>] netif_alloc_netdev_queues net/core/dev.c:8380 [inline] [<00000000d6dcb63e>] alloc_netdev_mqs+0x600/0xcc0 net/core/dev.c:8970 [<00000000867e172f>] sit_init_net+0x295/0xa40 net/ipv6/sit.c:1848 [<00000000871019fa>] ops_init+0xad/0x3e0 net/core/net_namespace.c:129 [<00000000319507f6>] setup_net+0x2ba/0x690 net/core/net_namespace.c:314 [<0000000087db4f96>] copy_net_ns+0x1dc/0x330 net/core/net_namespace.c:437 [<0000000057efc651>] create_new_namespaces+0x382/0x730 kernel/nsproxy.c:107 [<00000000676f83de>] copy_namespaces+0x2ed/0x3d0 kernel/nsproxy.c:165 [<0000000030b74bac>] copy_process.part.27+0x231e/0x6db0 kernel/fork.c:1919 [<00000000fff78746>] copy_process kernel/fork.c:1713 [inline] [<00000000fff78746>] _do_fork+0x1bc/0xe90 kernel/fork.c:2224 [<000000001c2e0d1c>] do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290 [<00000000ec48bd44>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<0000000039acff8a>] 0xffffffffffffffff Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-02net: dsa: mv88e6xxx: Fix statistics on mv88e6161Andrew Lunn1-1/+1
Despite what the datesheet says, the silicon implements the older way of snapshoting the statistics. Change the op. Reported-by: Chris.Healy@zii.aero Tested-by: Chris.Healy@zii.aero Fixes: 0ac64c394900 ("net: dsa: mv88e6xxx: mv88e6161 uses mv88e6320 stats snapshot") Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01geneve: correctly handle ipv6.disable module parameterJiri Benc1-3/+8
When IPv6 is compiled but disabled at runtime, geneve_sock_add returns -EAFNOSUPPORT. For metadata based tunnels, this causes failure of the whole operation of bringing up the tunnel. Ignore failure of IPv6 socket creation for metadata based tunnels caused by IPv6 not being available. This is the same fix as what commit d074bf960044 ("vxlan: correctly handle ipv6.disable module parameter") is doing for vxlan. Note there's also commit c0a47e44c098 ("geneve: should not call rt6_lookup() when ipv6 was disabled") which fixes a similar issue but for regular tunnels, while this patch is needed for metadata based tunnels. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller3-5/+6
Alexei Starovoitov says: ==================== pull-request: bpf 2019-03-01 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) fix sanitation rewrite, from Daniel. 2) fix error path on map_new_fd, from Peng. 3) fix icache flush address, from Paul. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01net: dsa: mv88e6xxx: prevent interrupt storm caused by mv88e6390x_port_set_cmodeHeiner Kallweit3-0/+15
When debugging another issue I faced an interrupt storm in this driver (88E6390, port 9 in SGMII mode), consisting of alternating link-up / link-down interrupts. Analysis showed that the driver wanted to set a cmode that was set already. But so far mv88e6390x_port_set_cmode() doesn't check this and powers down SERDES, what causes the link to break, and eventually results in the described interrupt storm. Fix this by checking whether the cmode actually changes. We want that the very first call to mv88e6390x_port_set_cmode() always configures the registers, therefore initialize port.cmode with a value that is different from any supported cmode value. We have to take care that we only init the ports cmode once chip->info->num_ports is set. v2: - add small helper and init the number of actual ports only Fixes: 364e9d7776a3 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change") Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01bpf: fix sanitation rewrite in case of non-pointersDaniel Borkmann1-1/+2
Marek reported that he saw an issue with the below snippet in that timing measurements where off when loaded as unpriv while results were reasonable when loaded as privileged: [...] uint64_t a = bpf_ktime_get_ns(); uint64_t b = bpf_ktime_get_ns(); uint64_t delta = b - a; if ((int64_t)delta > 0) { [...] Turns out there is a bug where a corner case is missing in the fix d3bd7413e0ca ("bpf: fix sanitation of alu op with pointer / scalar type from different paths"), namely fixup_bpf_calls() only checks whether aux has a non-zero alu_state, but it also needs to test for the case of BPF_ALU_NON_POINTER since in both occasions we need to skip the masking rewrite (as there is nothing to mask). Fixes: d3bd7413e0ca ("bpf: fix sanitation of alu op with pointer / scalar type from different paths") Reported-by: Marek Majkowski <marek@cloudflare.com> Reported-by: Arthur Fabre <afabre@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/netdev/CAJPywTJqP34cK20iLM5YmUMz9KXQOdu1-+BZrGMAGgLuBWz7fg@mail.gmail.com/T/ Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-01ipv4: Add ICMPv6 support when parse route ipprotoHangbin Liu4-7/+17
For ip rules, we need to use 'ipproto ipv6-icmp' to match ICMPv6 headers. But for ip -6 route, currently we only support tcp, udp and icmp. Add ICMPv6 support so we can match ipv6-icmp rules for route lookup. v2: As David Ahern and Sabrina Dubroca suggested, Add an argument to rtm_getroute_parse_ip_proto() to handle ICMP/ICMPv6 with different family. Reported-by: Jianlin Shi <jishi@redhat.com> Fixes: eacb9384a3fe ("ipv6: support sport, dport and ip_proto in RTM_GETROUTE") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-02MIPS: eBPF: Fix icache flush end addressPaul Burton1-1/+1
The MIPS eBPF JIT calls flush_icache_range() in order to ensure the icache observes the code that we just wrote. Unfortunately it gets the end address calculation wrong due to some bad pointer arithmetic. The struct jit_ctx target field is of type pointer to u32, and as such adding one to it will increment the address being pointed to by 4 bytes. Therefore in order to find the address of the end of the code we simply need to add the number of 4 byte instructions emitted, but we mistakenly add the number of instructions multiplied by 4. This results in the call to flush_icache_range() operating on a memory region 4x larger than intended, which is always wasteful and can cause crashes if we overrun into an unmapped page. Fix this by correcting the pointer arithmetic to remove the bogus multiplication, and use braces to remove the need for a set of brackets whilst also making it obvious that the target field is a pointer. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.") Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: netdev@vger.kernel.org Cc: bpf@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-01lan743x: Fix TX Stall IssueBryan Whitehead1-4/+12
It has been observed that tx queue stalls while downloading from certain web sites (example www.speedtest.net) The cause has been tracked down to a corner case where dma descriptors where not setup properly. And there for a tx completion interrupt was not signaled. This fix corrects the problem by properly marking the end of a multi descriptor transmission. Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver") Signed-off-by: Bryan Whitehead <Bryan.Whitehead@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01net: phy: phylink: fix uninitialized variable in phylink_get_mac_stateHeiner Kallweit1-0/+4
When debugging an issue I found implausible values in state->pause. Reason in that state->pause isn't initialized and later only single bits are changed. Also the struct itself isn't initialized in phylink_resolve(). So better initialize state->pause and other not yet initialized fields. v2: - use right function name in subject v3: - initialize additional fields Fixes: 9525ae83959b ("phylink: add phylink infrastructure") Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01net: aquantia: regression on cpus with high cores: set mode with 8 queuesDmitry Bogdanov4-0/+29
Recently the maximum number of queues was increased up to 8, but NIC was not fully configured for 8 queues. In setups with more than 4 CPU cores parts of TX traffic gets lost if the kernel routes it to queues 4th-8th. This patch sets a tx hw traffic mode with 8 queues. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202651 Fixes: 71a963cfc50b ("net: aquantia: increase max number of hw queues") Reported-by: Nicholas Johnson <nicholas.johnson@outlook.com.au> Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com> Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01selftests: fixes for UDP GROPaolo Abeni2-17/+33
The current implementation for UDP GRO tests is racy: the receiver may flush the RX queue while the sending is still transmitting and incorrectly report RX errors, with a wrong number of packet received. Add explicit timeouts to the receiver for both connection activation (first packet received for UDP) and reception completion, so that in the above critical scenario the receiver will wait for the transfer completion. Fixes: 3327a9c46352 ("selftests: add functionals test for UDP GRO") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-01Merge tag 'iommu-fix-v5.0-rc8' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU fix from Joerg Roedel: "One important fix for a memory corruption issue in the Intel VT-d driver that triggers on hardware with deep PCI hierarchies" * tag 'iommu-fix-v5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/dmar: Fix buffer overflow during PCI bus notification
2019-03-01Merge branch 'akpm' (patches from Andrew)Linus Torvalds5-4/+59
Merge misc fixes from Andrew Morton: "2 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: hugetlbfs: fix races and page leaks during migration kasan: turn off asan-stack for clang-8 and earlier
2019-03-01hugetlbfs: fix races and page leaks during migrationMike Kravetz3-3/+36
hugetlb pages should only be migrated if they are 'active'. The routines set/clear_page_huge_active() modify the active state of hugetlb pages. When a new hugetlb page is allocated at fault time, set_page_huge_active is called before the page is locked. Therefore, another thread could race and migrate the page while it is being added to page table by the fault code. This race is somewhat hard to trigger, but can be seen by strategically adding udelay to simulate worst case scheduling behavior. Depending on 'how' the code races, various BUG()s could be triggered. To address this issue, simply delay the set_page_huge_active call until after the page is successfully added to the page table. Hugetlb pages can also be leaked at migration time if the pages are associated with a file in an explicitly mounted hugetlbfs filesystem. For example, consider a two node system with 4GB worth of huge pages available. A program mmaps a 2G file in a hugetlbfs filesystem. It then migrates the pages associated with the file from one node to another. When the program exits, huge page counts are as follows: node0 1024 free_hugepages 1024 nr_hugepages node1 0 free_hugepages 1024 nr_hugepages Filesystem Size Used Avail Use% Mounted on nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepool That is as expected. 2G of huge pages are taken from the free_hugepages counts, and 2G is the size of the file in the explicitly mounted filesystem. If the file is then removed, the counts become: node0 1024 free_hugepages 1024 nr_hugepages node1 1024 free_hugepages 1024 nr_hugepages Filesystem Size Used Avail Use% Mounted on nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepool Note that the filesystem still shows 2G of pages used, while there actually are no huge pages in use. The only way to 'fix' the filesystem accounting is to unmount the filesystem If a hugetlb page is associated with an explicitly mounted filesystem, this information in contained in the page_private field. At migration time, this information is not preserved. To fix, simply transfer page_private from old to new page at migration time if necessary. There is a related race with removing a huge page from a file and migration. When a huge page is removed from the pagecache, the page_mapping() field is cleared, yet page_private remains set until the page is actually freed by free_huge_page(). A page could be migrated while in this state. However, since page_mapping() is not set the hugetlbfs specific routine to transfer page_private is not called and we leak the page count in the filesystem. To fix that, check for this condition before migrating a huge page. If the condition is detected, return EBUSY for the page. Link: http://lkml.kernel.org/r/74510272-7319-7372-9ea6-ec914734c179@oracle.com Link: http://lkml.kernel.org/r/20190212221400.3512-1-mike.kravetz@oracle.com Fixes: bcc54222309c ("mm: hugetlb: introduce page_huge_active") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: <stable@vger.kernel.org> [mike.kravetz@oracle.com: v2] Link: http://lkml.kernel.org/r/7534d322-d782-8ac6-1c8d-a8dc380eb3ab@oracle.com [mike.kravetz@oracle.com: update comment and changelog] Link: http://lkml.kernel.org/r/420bcfd6-158b-38e4-98da-26d0cd85bd01@oracle.com Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-01kasan: turn off asan-stack for clang-8 and earlierArnd Bergmann2-1/+23
Building an arm64 allmodconfig kernel with clang results in over 140 warnings about overly large stack frames, the worst ones being: drivers/gpu/drm/panel/panel-sitronix-st7789v.c:196:12: error: stack frame size of 20224 bytes in function 'st7789v_prepare' drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td028ttec1.c:196:12: error: stack frame size of 13120 bytes in function 'td028ttec1_panel_enable' drivers/usb/host/max3421-hcd.c:1395:1: error: stack frame size of 10048 bytes in function 'max3421_spi_thread' drivers/net/wan/slic_ds26522.c:209:12: error: stack frame size of 9664 bytes in function 'slic_ds26522_probe' drivers/crypto/ccp/ccp-ops.c:2434:5: error: stack frame size of 8832 bytes in function 'ccp_run_cmd' drivers/media/dvb-frontends/stv0367.c:1005:12: error: stack frame size of 7840 bytes in function 'stv0367ter_algo' None of these happen with gcc today, and almost all of these are the result of a single known issue in llvm. Hopefully it will eventually get fixed with the clang-9 release. In the meantime, the best idea I have is to turn off asan-stack for clang-8 and earlier, so we can produce a kernel that is safe to run. I have posted three patches that address the frame overflow warnings that are not addressed by turning off asan-stack, so in combination with this change, we get much closer to a clean allmodconfig build, which in turn is necessary to do meaningful build regression testing. It is still possible to turn on the CONFIG_ASAN_STACK option on all versions of clang, and it's always enabled for gcc, but when CONFIG_COMPILE_TEST is set, the option remains invisible, so allmodconfig and randconfig builds (which are normally done with a forced CONFIG_COMPILE_TEST) will still result in a mostly clean build. Link: http://lkml.kernel.org/r/20190222222950.3997333-1-arnd@arndb.de Link: https://bugs.llvm.org/show_bug.cgi?id=38809 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Qian Cai <cai@lca.pw> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-01Merge tag 'drm-fixes-2019-03-01' of git://anongit.freedesktop.org/drm/drmLinus Torvalds4-4/+37
Pull drm fixes from Dave Airlie: "Three final fixes, one for a feature that is new in this kernel, one bochs fix for qemu riscv and one atomic modesetting fix. I've left a few of the other late fixes until next as I didn't want to throw in anything that wasn't really necessary" * tag 'drm-fixes-2019-03-01' of git://anongit.freedesktop.org/drm/drm: drm/bochs: Fix the ID mismatch error drm: Block fb changes for async plane updates drm/amd/display: Use vrr friendly pageflip throttling in DC.
2019-03-01bpf: drop refcount if bpf_map_new_fd() fails in map_create()Peng Sun1-2/+2
In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun <sironhide0null@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-01Merge tag 'qcom-fixes-for-5.0-rc8' of ↵Arnd Bergmann1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux into arm/fixes Qualcomm ARM64 Fixes for 5.0-rc8 * Fix TZ memory area size to avoid crashes during boot * tag 'qcom-fixes-for-5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux: arm64: dts: qcom: msm8998: Extend TZ reserved memory area
2019-03-01Merge tag 'tee-fix-for-v5.0' of ↵Arnd Bergmann1-1/+3
https://git.linaro.org/people/jens.wiklander/linux-tee into arm/fixes OP-TEE driver - add missing of_node_put after of_device_is_available * tag 'tee-fix-for-v5.0' of https://git.linaro.org/people/jens.wiklander/linux-tee: tee: optee: add missing of_node_put after of_device_is_available
2019-02-28Merge tag 'mips_fixes_5.0_4' of ↵Linus Torvalds4-5/+13
git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS fixes from Paul Burton: "A few more MIPS fixes: - Fix 16b cmpxchg() operations which could erroneously fail if bits 15:8 of the old value are non-zero. In practice I'm not aware of any actual users of 16b cmpxchg() on MIPS, but this fixes the support for it was was introduced in v4.13. - Provide a struct device to dma_alloc_coherent for Lantiq XWAY systems with a "Voice MIPS Macro Core" (VMMC) device. - Provide DMA masks for BCM63xx ethernet devices, fixing a regression introduced in v4.19. - Fix memblock reservation for the kernel when the system has a non-zero PHYS_OFFSET, correcting the memblock conversion performed in v4.20" * tag 'mips_fixes_5.0_4' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: MIPS: fix memory setup for platforms with PHYS_OFFSET != 0 MIPS: BCM63XX: provide DMA masks for ethernet devices MIPS: lantiq: pass struct device to DMA API functions MIPS: fix truncation in __cmpxchg_small for short values
2019-02-28Merge tag 'for-linus-5.0-ofs1' of ↵Linus Torvalds1-4/+0
git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux Pull orangefs fixlet from Mike Marshall: "Remove two un-needed BUG_ONs" * tag 'for-linus-5.0-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux: orangefs: remove two un-needed BUG_ONs...
2019-02-28net: dsa: mv88e6xxx: power serdes on/off for 10G interfaces on 6390XMaxime Chevallier1-2/+2
Upon setting the cmode on 6390 and 6390X, the associated serdes interfaces must be powered off/on. Both 6390X and 6390 share code to do so, but it currently uses the 6390 specific helper mv88e6390_serdes_power() to disable and enable the serdes interface. This call will fail silently on 6390X when trying so set a 10G interface such as XAUI or RXAUI, since mv88e6390_serdes_power() internally grabs the lane number based on modes supported by the 6390, and returns 0 when getting -ENODEV as a lane number. Using mv88e6390x_serdes_power() should be safe here, since we explicitly rule-out all ports but the 9 and 10, and because modes supported by 6390 ports 9 and 10 are a subset of those supported on 6390X. This was tested on 6390X using RXAUI mode. Fixes: 364e9d7776a3 ("net: dsa: mv88e6xxx: Power on/off SERDES on cmode change") Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28net: dsa: mv88e6xxx: Fix u64 statisticsAndrew Lunn1-1/+1
The switch maintains u64 counters for the number of octets sent and received. These are kept as two u32's which need to be combined. Fix the combing, which wrongly worked on u16's. Fixes: 80c4627b2719 ("dsa: mv88x6xxx: Refactor getting a single statistic") Reported-by: Chris Healy <Chris.Healy@zii.aero> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28xen-netback: don't populate the hash cache on XenBus disconnectIgor Druzhinin2-0/+9
Occasionally, during the disconnection procedure on XenBus which includes hash cache deinitialization there might be some packets still in-flight on other processors. Handling of these packets includes hashing and hash cache population that finally results in hash cache data structure corruption. In order to avoid this we prevent hashing of those packets if there are no queues initialized. In that case RCU protection of queues guards the hash cache as well. Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28xen-netback: fix occasional leak of grant ref mappings under memory pressureIgor Druzhinin1-5/+5
Zero-copy callback flag is not yet set on frag list skb at the moment xenvif_handle_frag_list() returns -ENOMEM. This eventually results in leaking grant ref mappings since xenvif_zerocopy_callback() is never called for these fragments. Those eventually build up and cause Xen to kill Dom0 as the slots get reused for new mappings: "d0v0 Attempt to implicitly unmap a granted PTE c010000329fce005" That behavior is observed under certain workloads where sudden spikes of page cache writes coexist with active atomic skb allocations from network traffic. Additionally, rework the logic to deal with frag_list deallocation in a single place. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28sctp: chunk.c: correct format string for size_t in printkMatthias Maennich1-1/+1
According to Documentation/core-api/printk-formats.rst, size_t should be printed with %zu, rather than %Zu. In addition, using %Zu triggers a warning on clang (-Wformat-extra-args): net/sctp/chunk.c:196:25: warning: data argument not used by format string [-Wformat-extra-args] __func__, asoc, max_data); ~~~~~~~~~~~~~~~~^~~~~~~~~ ./include/linux/printk.h:440:49: note: expanded from macro 'pr_warn_ratelimited' printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~ ./include/linux/printk.h:424:17: note: expanded from macro 'printk_ratelimited' printk(fmt, ##__VA_ARGS__); \ ~~~ ^ Fixes: 5b5e0928f742 ("lib/vsprintf.c: remove %Z support") Link: https://github.com/ClangBuiltLinux/linux/issues/378 Signed-off-by: Matthias Maennich <maennich@google.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-28net: netem: fix skb length BUG_ON in __skb_to_sgvecSheng Lan1-3/+7
It can be reproduced by following steps: 1. virtio_net NIC is configured with gso/tso on 2. configure nginx as http server with an index file bigger than 1M bytes 3. use tc netem to produce duplicate packets and delay: tc qdisc add dev eth0 root netem delay 100ms 10ms 30% duplicate 90% 4. continually curl the nginx http server to get index file on client 5. BUG_ON is seen quickly [10258690.371129] kernel BUG at net/core/skbuff.c:4028! [10258690.371748] invalid opcode: 0000 [#1] SMP PTI [10258690.372094] CPU: 5 PID: 0 Comm: swapper/5 Tainted: G W 5.0.0-rc6 #2 [10258690.372094] RSP: 0018:ffffa05797b43da0 EFLAGS: 00010202 [10258690.372094] RBP: 00000000000005ea R08: 0000000000000000 R09: 00000000000005ea [10258690.372094] R10: ffffa0579334d800 R11: 00000000000002c0 R12: 0000000000000002 [10258690.372094] R13: 0000000000000000 R14: ffffa05793122900 R15: ffffa0578f7cb028 [10258690.372094] FS: 0000000000000000(0000) GS:ffffa05797b40000(0000) knlGS:0000000000000000 [10258690.372094] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [10258690.372094] CR2: 00007f1a6dc00868 CR3: 000000001000e000 CR4: 00000000000006e0 [10258690.372094] Call Trace: [10258690.372094] <IRQ> [10258690.372094] skb_to_sgvec+0x11/0x40 [10258690.372094] start_xmit+0x38c/0x520 [virtio_net] [10258690.372094] dev_hard_start_xmit+0x9b/0x200 [10258690.372094] sch_direct_xmit+0xff/0x260 [10258690.372094] __qdisc_run+0x15e/0x4e0 [10258690.372094] net_tx_action+0x137/0x210 [10258690.372094] __do_softirq+0xd6/0x2a9 [10258690.372094] irq_exit+0xde/0xf0 [10258690.372094] smp_apic_timer_interrupt+0x74/0x140 [10258690.372094] apic_timer_interrupt+0xf/0x20 [10258690.372094] </IRQ> In __skb_to_sgvec(), the skb->len is not equal to the sum of the skb's linear data size and nonlinear data size, thus BUG_ON triggered. Because the skb is cloned and a part of nonlinear data is split off. Duplicate packet is cloned in netem_enqueue() and may be delayed some time in qdisc. When qdisc len reached the limit and returns NET_XMIT_DROP, the skb will be retransmit later in write queue. the skb will be fragmented by tso_fragment(), the limit size that depends on cwnd and mss decrease, the skb's nonlinear data will be split off. The length of the skb cloned by netem will not be updated. When we use virtio_net NIC and invoke skb_to_sgvec(), the BUG_ON trigger. To fix it, netem returns NET_XMIT_SUCCESS to upper stack when it clones a duplicate packet. Fixes: 35d889d1 ("sch_netem: fix skb leak in netem_enqueue()") Signed-off-by: Sheng Lan <lansheng@huawei.com> Reported-by: Qin Ji <jiqin.ji@huawei.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>