user/sven/linux.git/kernel, branch v5.6.11

PM: hibernate: Freeze kernel threads in software_resume()

2020-05-06T06:16:38Z

commit 2351f8d295ed63393190e39c2f7c1fee1a80578f upstream. Currently the kernel threads are not frozen in software_resume(), so between dpm_suspend_start(PMSG_QUIESCE) and resume_target_kernel(), system_freezable_power_efficient_wq can still try to submit SCSI commands and this can cause a panic since the low level SCSI driver (e.g. hv_storvsc) has quiesced the SCSI adapter and can not accept any SCSI commands: https://lkml.org/lkml/2020/4/10/47 At first I posted a fix (https://lkml.org/lkml/2020/4/21/1318) trying to resolve the issue from hv_storvsc, but with the help of Bart Van Assche, I realized it's better to fix software_resume(), since this looks like a generic issue, not only pertaining to SCSI. Cc: All applicable Signed-off-by: Dexuan Cui Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

sched/vtime: Work around an unitialized variable warning

2020-05-02T06:51:02Z

[ Upstream commit e0d648f9d883ec1efab261af158d73aa30e9dd12 ] Work around this warning: kernel/sched/cputime.c: In function ‘kcpustat_field’: kernel/sched/cputime.c:1007:6: warning: ‘val’ may be used uninitialized in this function [-Wmaybe-uninitialized] because GCC can't see that val is used only when err is 0. Acked-by: Peter Zijlstra Signed-off-by: Borislav Petkov Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200327214334.GF8015@zn.tnic Signed-off-by: Sasha Levin

sched/isolation: Allow "isolcpus=" to skip unknown sub-parameters

2020-05-02T06:51:02Z

[ Upstream commit 3662daf023500dc084fa3b96f68a6f46179ddc73 ] The "isolcpus=" parameter allows sub-parameters before the cpulist is specified, and if the parser detects an unknown sub-parameters the whole parameter will be ignored. This design is incompatible with itself when new sub-parameters are added. An older kernel will not recognize the new sub-parameter and will invalidate the whole parameter so the CPU isolation will not take effect. It emits a warning: isolcpus: Error, unknown flag The better and compatible way is to allow "isolcpus=" to skip unknown sub-parameters, so that even if new sub-parameters are added an older kernel will still be able to behave as usual even if with the new sub-parameter specified on the command line. Ideally this should have been there when the first sub-parameter for "isolcpus=" was introduced. Suggested-by: Thomas Gleixner Signed-off-by: Peter Xu Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200403223517.406353-1-peterx@redhat.com Signed-off-by: Sasha Levin

signal: check sig before setting info in kill_pid_usb_asyncio

2020-05-02T06:50:57Z

[ Upstream commit eaec2b0bd30690575c581eebffae64bfb7f684ac ] In kill_pid_usb_asyncio, if signal is not valid, we do not need to set info struct. Signed-off-by: Zhiqiang Liu Acked-by: Christian Brauner Link: https://lore.kernel.org/r/f525fd08-1cf7-fb09-d20c-4359145eb940@huawei.com Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

bpf: Propagate expected_attach_type when verifying freplace programs

2020-05-02T06:50:56Z

commit 03f87c0b45b177ba5f6b4a9bbe9f95e4aba31026 upstream. For some program types, the verifier relies on the expected_attach_type of the program being verified in the verification process. However, for freplace programs, the attach type was not propagated along with the verifier ops, so the expected_attach_type would always be zero for freplace programs. This in turn caused the verifier to sometimes make the wrong call for freplace programs. For all existing uses of expected_attach_type for this purpose, the result of this was only false negatives (i.e., freplace functions would be rejected by the verifier even though they were valid programs for the target they were replacing). However, should a false positive be introduced, this can lead to out-of-bounds accesses and/or crashes. The fix introduced in this patch is to propagate the expected_attach_type to the freplace program during verification, and reset it after that is done. Fixes: be8704ff07d2 ("bpf: Introduce dynamic program extensions") Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/158773526726.293902.13257293296560360508.stgit@toke.dk Signed-off-by: Greg Kroah-Hartman

bpf: Fix handling of XADD on BTF memory

2020-05-02T06:50:54Z

commit 8ff3571f7e1bf3f293cc5e3dc14f2943f4fa7fcf upstream. check_xadd() can cause check_ptr_to_btf_access() to be executed with atype==BPF_READ and value_regno==-1 (meaning "just check whether the access is okay, don't tell me what type it will result in"). Handle that case properly and skip writing type information, instead of indexing into the registers at index -1 and writing into out-of-bounds memory. Note that at least at the moment, you can't actually write through a BTF pointer, so check_xadd() will reject the program after calling check_ptr_to_btf_access with atype==BPF_WRITE; but that's after the verifier has already corrupted memory. This patch assumes that BTF pointers are not available in unprivileged programs. Fixes: 9e15db66136a ("bpf: Implement accurate raw_tp context access via BTF") Signed-off-by: Jann Horn Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200417000007.10734-2-jannh@google.com Signed-off-by: Greg Kroah-Hartman

perf/core: fix parent pid/tid in task exit events

2020-05-02T06:50:53Z

commit f3bed55e850926614b9898fe982f66d2541a36a5 upstream. Current logic yields the child task as the parent. Before: $ perf record bash -c "perf list > /dev/null" $ perf script -D |grep 'FORK\|EXIT' 4387036190981094 0x5a70 [0x30]: PERF_RECORD_FORK(10472:10472):(10470:10470) 4387036606207580 0xf050 [0x30]: PERF_RECORD_EXIT(10472:10472):(10472:10472) 4387036607103839 0x17150 [0x30]: PERF_RECORD_EXIT(10470:10470):(10470:10470) ^ Note the repeated values here -------------------/ After: 383281514043 0x9d8 [0x30]: PERF_RECORD_FORK(2268:2268):(2266:2266) 383442003996 0x2180 [0x30]: PERF_RECORD_EXIT(2268:2268):(2266:2266) 383451297778 0xb70 [0x30]: PERF_RECORD_EXIT(2266:2266):(2265:2265) Fixes: 94d5d1b2d891 ("perf_counter: Report the cloning task as parent on perf_counter_fork()") Reported-by: KP Singh Signed-off-by: Ian Rogers Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200417182842.12522-1-irogers@google.com Signed-off-by: Greg Kroah-Hartman

sched/core: Fix reset-on-fork from RT with uclamp

2020-05-02T06:50:53Z

commit eaf5a92ebde5bca3bb2565616115bd6d579486cd upstream. uclamp_fork() resets the uclamp values to their default when the reset-on-fork flag is set. It also checks whether the task has a RT policy, and sets its uclamp.min to 1024 accordingly. However, during reset-on-fork, the task's policy is lowered to SCHED_NORMAL right after, hence leading to an erroneous uclamp.min setting for the new task if it was forked from RT. Fix this by removing the unnecessary check on rt_task() in uclamp_fork() as this doesn't make sense if the reset-on-fork flag is set. Fixes: 1a00d999971c ("sched/uclamp: Set default clamps for RT tasks") Reported-by: Chitti Babu Theegala Signed-off-by: Quentin Perret Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Patrick Bellasi Reviewed-by: Dietmar Eggemann Link: https://lkml.kernel.org/r/20200416085956.217587-1-qperret@google.com Signed-off-by: Greg Kroah-Hartman

cpumap: Avoid warning when CONFIG_DEBUG_PER_CPU_MAPS is enabled

2020-05-02T06:50:52Z

commit bc23d0e3f717ced21fbfacab3ab887d55e5ba367 upstream. When the kernel is built with CONFIG_DEBUG_PER_CPU_MAPS, the cpumap code can trigger a spurious warning if CONFIG_CPUMASK_OFFSTACK is also set. This happens because in this configuration, NR_CPUS can be larger than nr_cpumask_bits, so the initial check in cpu_map_alloc() is not sufficient to guard against hitting the warning in cpumask_check(). Fix this by explicitly checking the supplied key against the nr_cpumask_bits variable before calling cpu_possible(). Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP") Reported-by: Xiumei Mu Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Alexei Starovoitov Tested-by: Xiumei Mu Acked-by: Jesper Dangaard Brouer Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20200416083120.453718-1-toke@redhat.com Signed-off-by: Greg Kroah-Hartman

bpf: Forbid XADD on spilled pointers for unprivileged users

2020-05-02T06:50:46Z

commit 6e7e63cbb023976d828cdb22422606bf77baa8a9 upstream. When check_xadd() verifies an XADD operation on a pointer to a stack slot containing a spilled pointer, check_stack_read() verifies that the read, which is part of XADD, is valid. However, since the placeholder value -1 is passed as `value_regno`, check_stack_read() can only return a binary decision and can't return the type of the value that was read. The intent here is to verify whether the value read from the stack slot may be used as a SCALAR_VALUE; but since check_stack_read() doesn't check the type, and the type information is lost when check_stack_read() returns, this is not enforced, and a malicious user can abuse XADD to leak spilled kernel pointers. Fix it by letting check_stack_read() verify that the value is usable as a SCALAR_VALUE if no type information is passed to the caller. To be able to use __is_pointer_value() in check_stack_read(), move it up. Fix up the expected unprivileged error message for a BPF selftest that, until now, assumed that unprivileged users can use XADD on stack-spilled pointers. This also gives us a test for the behavior introduced in this patch for free. In theory, this could also be fixed by forbidding XADD on stack spills entirely, since XADD is a locked operation (for operations on memory with concurrency) and there can't be any concurrency on the BPF stack; but Alexei has said that he wants to keep XADD on stack slots working to avoid changes to the test suite [1]. The following BPF program demonstrates how to leak a BPF map pointer as an unprivileged user using this bug: // r7 = map_pointer BPF_LD_MAP_FD(BPF_REG_7, small_map), // r8 = launder(map_pointer) BPF_STX_MEM(BPF_DW, BPF_REG_FP, BPF_REG_7, -8), BPF_MOV64_IMM(BPF_REG_1, 0), ((struct bpf_insn) { .code = BPF_STX | BPF_DW | BPF_XADD, .dst_reg = BPF_REG_FP, .src_reg = BPF_REG_1, .off = -8 }), BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_FP, -8), // store r8 into map BPF_MOV64_REG(BPF_REG_ARG1, BPF_REG_7), BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP), BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -4), BPF_ST_MEM(BPF_W, BPF_REG_ARG2, 0, 0), BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), BPF_EXIT_INSN(), BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN() [1] https://lore.kernel.org/bpf/20200416211116.qxqcza5vo2ddnkdq@ast-mbp.dhcp.thefacebook.com/ Fixes: 17a5267067f3 ("bpf: verifier (add verifier core)") Signed-off-by: Jann Horn Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200417000007.10734-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman