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[PATCH AUTOSEL 5.11 32/38] selftests/vm: fix out-of-tree build

by Sasha Levin

From: Rong Chen <rong.a.chen(a)intel.com> [ Upstream commit 19ec368cbc7ee1915e78c120b7a49c7f14734192 ] When building out-of-tree, attempting to make target from $(OUTPUT) directory: make[1]: *** No rule to make target '$(OUTPUT)/protection_keys.c', needed by '$(OUTPUT)/protection_keys_32'. Link: https://lkml.kernel.org/r/20210315094700.522753-1-rong.a.chen@intel.com Signed-off-by: Rong Chen <rong.a.chen(a)intel.com> Reported-by: kernel test robot <lkp(a)intel.com> Cc: Shuah Khan <shuah(a)kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/vm/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index d42115e4284d..8b0cd421ebd3 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -101,7 +101,7 @@ endef ifeq ($(CAN_BUILD_I386),1) $(BINARIES_32): CFLAGS += -m32 $(BINARIES_32): LDLIBS += -lrt -ldl -lm -$(BINARIES_32): %_32: %.c +$(BINARIES_32): $(OUTPUT)/%_32: %.c $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(notdir $^) $(LDLIBS) -o $@ $(foreach t,$(TARGETS),$(eval $(call gen-target-rule-32,$(t)))) endif @@ -109,7 +109,7 @@ endif ifeq ($(CAN_BUILD_X86_64),1) $(BINARIES_64): CFLAGS += -m64 $(BINARIES_64): LDLIBS += -lrt -ldl -$(BINARIES_64): %_64: %.c +$(BINARIES_64): $(OUTPUT)/%_64: %.c $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(notdir $^) $(LDLIBS) -o $@ $(foreach t,$(TARGETS),$(eval $(call gen-target-rule-64,$(t)))) endif -- 2.30.1

4 years, 5 months

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[PATCH AUTOSEL 5.11 23/38] kselftest/arm64: sve: Do not use non-canonical FFR register value

by Sasha Levin

From: Andre Przywara <andre.przywara(a)arm.com> [ Upstream commit 7011d72588d16a9e5f5d85acbc8b10019809599c ] The "First Fault Register" (FFR) is an SVE register that mimics a predicate register, but clears bits when a load or store fails to handle an element of a vector. The supposed usage scenario is to initialise this register (using SETFFR), then *read* it later on to learn about elements that failed to load or store. Explicit writes to this register using the WRFFR instruction are only supposed to *restore* values previously read from the register (for context-switching only). As the manual describes, this register holds only certain values, it: "... contains a monotonic predicate value, in which starting from bit 0 there are zero or more 1 bits, followed only by 0 bits in any remaining bit positions." Any other value is UNPREDICTABLE and is not supposed to be "restored" into the register. The SVE test currently tries to write a signature pattern into the register, which is *not* a canonical FFR value. Apparently the existing setups treat UNPREDICTABLE as "read-as-written", but a new implementation actually only stores canonical values. As a consequence, the sve-test fails immediately when comparing the FFR value: ----------- # ./sve-test Vector length: 128 bits PID: 207 Mismatch: PID=207, iteration=0, reg=48 Expected [cf00] Got [0f00] Aborted ----------- Fix this by only populating the FFR with proper canonical values. Effectively the requirement described above limits us to 17 unique values over 16 bits worth of FFR, so we condense our signature down to 4 bits (2 bits from the PID, 2 bits from the generation) and generate the canonical pattern from it. Any bits describing elements above the minimum 128 bit are set to 0. This aligns the FFR usage to the architecture and fixes the test on microarchitectures implementing FFR in a more restricted way. Signed-off-by: Andre Przywara <andre.przywara(a)arm.com> Reviwed-by: Mark Brown <broonie(a)kernel.org> Link: https://lore.kernel.org/r/20210319120128.29452-1-andre.przywara@arm.com Signed-off-by: Will Deacon <will(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/selftests/arm64/fp/sve-test.S | 22 ++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S index 9210691aa998..e3e08d9c7020 100644 --- a/tools/testing/selftests/arm64/fp/sve-test.S +++ b/tools/testing/selftests/arm64/fp/sve-test.S @@ -284,16 +284,28 @@ endfunction // Set up test pattern in the FFR // x0: pid // x2: generation +// +// We need to generate a canonical FFR value, which consists of a number of +// low "1" bits, followed by a number of zeros. This gives us 17 unique values +// per 16 bits of FFR, so we create a 4 bit signature out of the PID and +// generation, and use that as the initial number of ones in the pattern. +// We fill the upper lanes of FFR with zeros. // Beware: corrupts P0. function setup_ffr mov x4, x30 - bl pattern + and w0, w0, #0x3 + bfi w0, w2, #2, #2 + mov w1, #1 + lsl w1, w1, w0 + sub w1, w1, #1 + ldr x0, =ffrref - ldr x1, =scratch - rdvl x2, #1 - lsr x2, x2, #3 - bl memcpy + strh w1, [x0], 2 + rdvl x1, #1 + lsr x1, x1, #3 + sub x1, x1, #2 + bl memclr mov x0, #0 ldr x1, =ffrref -- 2.30.1

4 years, 5 months

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[PATCH AUTOSEL 5.11 08/38] kunit: tool: Fix a python tuple typing error

by Sasha Levin

From: David Gow <davidgow(a)google.com> [ Upstream commit 7421b1a4d10c633ca5f14c8236d3e2c1de07e52b ] The first argument to namedtuple() should match the name of the type, which wasn't the case for KconfigEntryBase. Fixing this is enough to make mypy show no python typing errors again. Fixes 97752c39bd ("kunit: kunit_tool: Allow .kunitconfig to disable config items") Signed-off-by: David Gow <davidgow(a)google.com> Reviewed-by: Daniel Latypov <dlatypov(a)google.com> Acked-by: Brendan Higgins <brendanhiggins(a)google.com> Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/testing/kunit/kunit_config.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/kunit/kunit_config.py b/tools/testing/kunit/kunit_config.py index bdd60230764b..27fe086d2d0d 100644 --- a/tools/testing/kunit/kunit_config.py +++ b/tools/testing/kunit/kunit_config.py @@ -13,7 +13,7 @@ from typing import List, Set CONFIG_IS_NOT_SET_PATTERN = r'^# CONFIG_(\w+) is not set$' CONFIG_PATTERN = r'^CONFIG_(\w+)=(\S+|".*")$' -KconfigEntryBase = collections.namedtuple('KconfigEntry', ['name', 'value']) +KconfigEntryBase = collections.namedtuple('KconfigEntryBase', ['name', 'value']) class KconfigEntry(KconfigEntryBase): -- 2.30.1

4 years, 5 months

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[PATCH v7 1/4] lib: vsprintf: scanf: Negative number must have field width > 1

by Richard Fitzgerald

If a signed number field starts with a '-' the field width must be > 1, or unlimited, to allow at least one digit after the '-'. This patch adds a check for this. If a signed field starts with '-' and field_width == 1 the scanf will quit. It is ok for a signed number field to have a field width of 1 if it starts with a digit. In that case the single digit can be converted. Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> Reviewed-by: Petr Mladek <pmladek(a)suse.com> Acked-by: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> --- lib/vsprintf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 41ddc353ebb8..f78651e9b030 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -3466,8 +3466,12 @@ int vsscanf(const char *buf, const char *fmt, va_list args) str = skip_spaces(str); digit = *str; - if (is_sign && digit == '-') + if (is_sign && digit == '-') { + if (field_width == 1) + break; + digit = *(str + 1); + } if (!digit || (base == 16 && !isxdigit(digit)) -- 2.20.1

4 years, 5 months

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[RFC PATCH v5 00/10] KVM: selftests: some improvement and a new test for kvm page table

by Yanan Wang

Hi, This v5 series can mainly include two parts. Based on kvm queue branch: https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=queue In the first part, all the known hugetlb backing src types specified with different hugepage sizes are listed, so that we can specify use of hugetlb source of the exact granularity that we want, instead of the system default ones. And as all the known hugetlb page sizes are listed, it's appropriate for all architectures. Besides, a helper that can get granularity of different backing src types(anonumous/thp/hugetlb) is added, so that we can use the accurate backing src granularity for kinds of alignment or guest memory accessing of vcpus. In the second part, a new test is added: This test is added to serve as a performance tester and a bug reproducer for kvm page table code (GPA->HPA mappings), it gives guidance for the people trying to make some improvement for kvm. And the following explains what we can exactly do through this test. The function guest_code() can cover the conditions where a single vcpu or multiple vcpus access guest pages within the same memory region, in three VM stages(before dirty logging, during dirty logging, after dirty logging). Besides, the backing src memory type(ANONYMOUS/THP/HUGETLB) of the tested memory region can be specified by users, which means normal page mappings or block mappings can be chosen by users to be created in the test. If ANONYMOUS memory is specified, kvm will create normal page mappings for the tested memory region before dirty logging, and update attributes of the page mappings from RO to RW during dirty logging. If THP/HUGETLB memory is specified, kvm will create block mappings for the tested memory region before dirty logging, and split the blcok mappings into normal page mappings during dirty logging, and coalesce the page mappings back into block mappings after dirty logging is stopped. So in summary, as a performance tester, this test can present the performance of kvm creating/updating normal page mappings, or the performance of kvm creating/splitting/recovering block mappings, through execution time. When we need to coalesce the page mappings back to block mappings after dirty logging is stopped, we have to firstly invalidate *all* the TLB entries for the page mappings right before installation of the block entry, because a TLB conflict abort error could occur if we can't invalidate the TLB entries fully. We have hit this TLB conflict twice on aarch64 software implementation and fixed it. As this test can imulate process from dirty logging enabled to dirty logging stopped of a VM with block mappings, so it can also reproduce this TLB conflict abort due to inadequate TLB invalidation when coalescing tables. Links about the TLB conflict abort: https://lore.kernel.org/lkml/20201201201034.116760-3-wangyanan55@huawei.com/ --- Change logs: v4->v5: - Use synchronization(sem_wait) for time measurement - Add a new patch about TEST_ASSERT(patch 4) - Address Andrew Jones's comments for v4 series - Add Andrew Jones's R-b tags in some patches - v4: https://lore.kernel.org/lkml/20210302125751.19080-1-wangyanan55@huawei.com/ v3->v4: - Add a helper to get system default hugetlb page size - Add tags of Reviewed-by of Ben in the patches - v3: https://lore.kernel.org/lkml/20210301065916.11484-1-wangyanan55@huawei.com/ v2->v3: - Add tags of Suggested-by, Reviewed-by in the patches - Add a generic micro to get hugetlb page sizes - Some changes for suggestions about v2 series - v2: https://lore.kernel.org/lkml/20210225055940.18748-1-wangyanan55@huawei.com/ v1->v2: - Add a patch to sync header files - Add helpers to get granularity of different backing src types - Some changes for suggestions about v1 series - v1: https://lore.kernel.org/lkml/20210208090841.333724-1-wangyanan55@huawei.com/ --- Yanan Wang (10): tools headers: sync headers of asm-generic/hugetlb_encode.h tools headers: Add a macro to get HUGETLB page sizes for mmap KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing KVM: selftests: Print the errno besides error-string in TEST_ASSERT KVM: selftests: Make a generic helper to get vm guest mode strings KVM: selftests: Add a helper to get system configured THP page size KVM: selftests: Add a helper to get system default hugetlb page size KVM: selftests: List all hugetlb src types specified with page sizes KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers KVM: selftests: Add a test for kvm page table code include/uapi/linux/mman.h | 2 + tools/include/asm-generic/hugetlb_encode.h | 3 + tools/include/uapi/linux/mman.h | 2 + tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 3 + .../selftests/kvm/demand_paging_test.c | 8 +- .../selftests/kvm/dirty_log_perf_test.c | 14 +- .../testing/selftests/kvm/include/kvm_util.h | 4 +- .../testing/selftests/kvm/include/test_util.h | 21 +- .../selftests/kvm/kvm_page_table_test.c | 512 ++++++++++++++++++ tools/testing/selftests/kvm/lib/assert.c | 4 +- tools/testing/selftests/kvm/lib/kvm_util.c | 59 +- tools/testing/selftests/kvm/lib/test_util.c | 163 +++++- tools/testing/selftests/kvm/steal_time.c | 4 +- 14 files changed, 739 insertions(+), 61 deletions(-) create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c -- 2.23.0

4 years, 5 months

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[PATCH] userfaultfd/shmem: fix MCOPY_ATOMIC_CONTNUE error handling + accounting

by Axel Rasmussen

Previously, in the error path, we unconditionally removed the page from the page cache. But in the continue case, we didn't add it - it was already there because the page is used by a second (non-UFFD-registered) mapping. So, in that case, it's incorrect to remove it as the other mapping may still use it normally. For this error handling failure, trivially exercise it in the userfaultfd selftest, to detect this kind of bug in the future. Also, we previously were unconditionally calling shmem_inode_acct_block. In the continue case, however, this is incorrect, because we would have already accounted for the RAM usage when the page was originally allocated (since at this point it's already in the page cache). So, doing it in the continue case causes us to double-count. Fixes: 00da60b9d0a0 ("userfaultfd: support minor fault handling for shmem") Signed-off-by: Axel Rasmussen <axelrasmussen(a)google.com> --- mm/shmem.c | 15 ++++++++++----- tools/testing/selftests/vm/userfaultfd.c | 12 ++++++++++++ 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index d2e0e81b7d2e..5ac8ea737004 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2379,9 +2379,11 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, int ret; pgoff_t offset, max_off; - ret = -ENOMEM; - if (!shmem_inode_acct_block(inode, 1)) - goto out; + if (!is_continue) { + ret = -ENOMEM; + if (!shmem_inode_acct_block(inode, 1)) + goto out; + } if (is_continue) { ret = -EFAULT; @@ -2389,6 +2391,7 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, if (!page) goto out_unacct_blocks; } else if (!*pagep) { + ret = -ENOMEM; page = shmem_alloc_page(gfp, info, pgoff); if (!page) goto out_unacct_blocks; @@ -2486,12 +2489,14 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, out_release_unlock: pte_unmap_unlock(dst_pte, ptl); ClearPageDirty(page); - delete_from_page_cache(page); + if (!is_continue) + delete_from_page_cache(page); out_release: unlock_page(page); put_page(page); out_unacct_blocks: - shmem_inode_unacct_blocks(inode, 1); + if (!is_continue) + shmem_inode_unacct_blocks(inode, 1); goto out; } #endif /* CONFIG_USERFAULTFD */ diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index f6c86b036d0f..d8541a59dae5 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -485,6 +485,7 @@ static void wp_range(int ufd, __u64 start, __u64 len, bool wp) static void continue_range(int ufd, __u64 start, __u64 len) { struct uffdio_continue req; + int ret; req.range.start = start; req.range.len = len; @@ -493,6 +494,17 @@ static void continue_range(int ufd, __u64 start, __u64 len) if (ioctl(ufd, UFFDIO_CONTINUE, &req)) err("UFFDIO_CONTINUE failed for address 0x%" PRIx64, (uint64_t)start); + + /* + * Error handling within the kernel for continue is subtly different + * from copy or zeropage, so it may be a source of bugs. Trigger an + * error (-EEXIST) on purpose, to verify doing so doesn't cause a BUG. + */ + req.mapped = 0; + ret = ioctl(ufd, UFFDIO_CONTINUE, &req); + if (ret >= 0 || req.mapped != -EEXIST) + err("failed to exercise UFFDIO_CONTINUE error handling, ret=%d, mapped=%" PRId64, + ret, req.mapped); } static void *locking_thread(void *arg) -- 2.31.0.291.g576ba9dcdaf-goog

4 years, 5 months

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[PATCH] selftests/timers: remove unneeded semicolon

by Jiapeng Chong

Fix the following coccicheck warnings: ./tools/testing/selftests/timers/nanosleep.c:75:2-3: Unneeded semicolon Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- tools/testing/selftests/timers/nanosleep.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/timers/nanosleep.c b/tools/testing/selftests/timers/nanosleep.c index 71b5441..433a096 100644 --- a/tools/testing/selftests/timers/nanosleep.c +++ b/tools/testing/selftests/timers/nanosleep.c @@ -72,7 +72,7 @@ char *clockstring(int clockid) return "CLOCK_BOOTTIME_ALARM"; case CLOCK_TAI: return "CLOCK_TAI"; - }; + } return "UNKNOWN_CLOCKID"; } -- 1.8.3.1

4 years, 5 months

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[PATCH] selftests/timers: Fix spelling mistake "clocksourc" -> "clocksource"

by Colin King

From: Colin Ian King <colin.king(a)canonical.com> There is a spelling mistake in a comment. Fix it. Signed-off-by: Colin Ian King <colin.king(a)canonical.com> --- tools/testing/selftests/timers/clocksource-switch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/timers/clocksource-switch.c b/tools/testing/selftests/timers/clocksource-switch.c index bfc974b4572d..2d66abd877e6 100644 --- a/tools/testing/selftests/timers/clocksource-switch.c +++ b/tools/testing/selftests/timers/clocksource-switch.c @@ -3,7 +3,7 @@ * (C) Copyright IBM 2012 * Licensed under the GPLv2 * - * NOTE: This is a meta-test which quickly changes the clocksourc and + * NOTE: This is a meta-test which quickly changes the clocksource and * then uses other tests to detect problems. Thus this test requires * that the inconsistency-check and nanosleep tests be present in the * same directory it is run from. -- 2.30.2

4 years, 5 months

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[PATCH v5] selftests: fix prepending $(OUTPUT) to $(TEST_PROGS)

by Ilya Leoshkevich

Currently the following command produces an error message: linux# make kselftest TARGETS=bpf O=/mnt/linux-build # selftests: bpf: test_libbpf.sh # ./test_libbpf.sh: line 23: ./test_libbpf_open: No such file or directory # test_libbpf: failed at file test_l4lb.o # selftests: test_libbpf [FAILED] The error message might not affect the return code of make, therefore one needs to grep make output in order to detect it. This is not the only instance of the same underlying problem; any test with more than one element in $(TEST_PROGS) fails the same way. Another example: linux# make O=/mnt/linux-build TARGETS=splice kselftest [...] # ./short_splice_read.sh: 15: ./splice_read: not found # FAIL: /sys/module/test_module/sections/.init.text 2 not ok 2 selftests: splice: short_splice_read.sh # exit=1 The current logic prepends $(OUTPUT) only to the first member of $(TEST_PROGS). After that, run_one() does cd `dirname $TEST` For all tests except the first one, `dirname $TEST` is ., which means they cannot access the files generated in $(OUTPUT). Fix by using $(addprefix) to prepend $(OUTPUT)/ to each member of $(TEST_PROGS). Fixes: 1a940687e424 ("selftests: lib.mk: copy test scripts and test files for make O=dir run") Signed-off-by: Ilya Leoshkevich <iii(a)linux.ibm.com> --- v1->v2: - Append / to $(OUTPUT). - Use $(addprefix) instead of $(foreach). v2->v3: - Split the patch in two. - Improve the commit message. v3: https://lore.kernel.org/linux-kselftest/20191024121347.22189-1-iii@linux.ib… v3->v4: - Drop the first patch. - Add a note regarding make return code to the commit message. v4: https://lore.kernel.org/linux-kselftest/20191115150428.61131-1-iii@linux.ib… v4->v5: - Add another reproducer to the commit message. tools/testing/selftests/lib.mk | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index a5ce26d548e4..be17462fe146 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -74,7 +74,8 @@ ifdef building_out_of_srctree rsync -aq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT); \ fi @if [ "X$(TEST_PROGS)" != "X" ]; then \ - $(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) $(OUTPUT)/$(TEST_PROGS)) ; \ + $(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) \ + $(addprefix $(OUTPUT)/,$(TEST_PROGS))) ; \ else \ $(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS)); \ fi -- 2.29.2

4 years, 5 months

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[PATCH v6 0/8] Fork brute force attack mitigation

by John Wood

Attacks against vulnerable userspace applications with the purpose to break ASLR or bypass canaries traditionally use some level of brute force with the help of the fork system call. This is possible since when creating a new process using fork its memory contents are the same as those of the parent process (the process that called the fork system call). So, the attacker can test the memory infinite times to find the correct memory values or the correct memory addresses without worrying about crashing the application. Based on the above scenario it would be nice to have this detected and mitigated, and this is the goal of this patch serie. Specifically the following attacks are expected to be detected: 1.- Launching (fork()/exec()) a setuid/setgid process repeatedly until a desirable memory layout is got (e.g. Stack Clash). 2.- Connecting to an exec()ing network daemon (e.g. xinetd) repeatedly until a desirable memory layout is got (e.g. what CTFs do for simple network service). 3.- Launching processes without exec() (e.g. Android Zygote) and exposing state to attack a sibling. 4.- Connecting to a fork()ing network daemon (e.g. apache) repeatedly until the previously shared memory layout of all the other children is exposed (e.g. kind of related to HeartBleed). In each case, a privilege boundary has been crossed: Case 1: setuid/setgid process Case 2: network to local Case 3: privilege changes Case 4: network to local So, what will really be detected are fork/exec brute force attacks that cross any of the commented bounds. The implementation details and comparison against other existing implementations can be found in the "Documentation" patch. Knowing all this information I will explain now the different patches: The 1/8 patch defines a new LSM hook to get the fatal signal of a task. This will be useful during the attack detection phase. The 2/8 patch defines a new LSM and manages the statistical data shared by all the fork hierarchy processes. The 3/8 patch detects a fork/exec brute force attack. The 4/8 patch narrows the detection taken into account the privilege boundary crossing. The 5/8 patch mitigates a brute force attack. The 6/8 patch adds self-tests to validate the Brute LSM expectations. The 7/8 patch adds the documentation to explain this implementation. The 8/8 patch updates the maintainers file. This patch serie is a task of the KSPP [1] and can also be accessed from my github tree [2] in the "brute_v6" branch. [1] https://github.com/KSPP/linux/issues/39 [2] https://github.com/johwood/linux/ The previous versions can be found in: RFC https://lore.kernel.org/kernel-hardening/20200910202107.3799376-1-keescook@… Version 2 https://lore.kernel.org/kernel-hardening/20201025134540.3770-1-john.wood@gm… Version 3 https://lore.kernel.org/lkml/20210221154919.68050-1-john.wood@gmx.com/ Version 4 https://lore.kernel.org/lkml/20210227150956.6022-1-john.wood@gmx.com/ Version 5 https://lore.kernel.org/kernel-hardening/20210227153013.6747-1-john.wood@gm… Changelog RFC -> v2 ------------------- - Rename this feature with a more suitable name (Jann Horn, Kees Cook). - Convert the code to an LSM (Kees Cook). - Add locking to avoid data races (Jann Horn). - Add a new LSM hook to get the fatal signal of a task (Jann Horn, Kees Cook). - Add the last crashes timestamps list to avoid false positives in the attack detection (Jann Horn). - Use "period" instead of "rate" (Jann Horn). - Other minor changes suggested (Jann Horn, Kees Cook). Changelog v2 -> v3 ------------------ - Compute the application crash period on an on-going basis (Kees Cook). - Detect a brute force attack through the execve system call (Kees Cook). - Detect an slow brute force attack (Randy Dunlap). - Fine tuning the detection taken into account privilege boundary crossing (Kees Cook). - Taken into account only fatal signals delivered by the kernel (Kees Cook). - Remove the sysctl attributes to fine tuning the detection (Kees Cook). - Remove the prctls to allow per process enabling/disabling (Kees Cook). - Improve the documentation (Kees Cook). - Fix some typos in the documentation (Randy Dunlap). - Add self-test to validate the expectations (Kees Cook). Changelog v3 -> v4 ------------------ - Fix all the warnings shown by the tool "scripts/kernel-doc" (Randy Dunlap). Changelog v4 -> v5 ------------------ - Fix some typos (Randy Dunlap). Changelog v5 -> v6 ------------------ - Fix a reported deadlock (kernel test robot). - Add high level details to the documentation (Andi Kleen). Any constructive comments are welcome. Thanks. John Wood (8): security: Add LSM hook at the point where a task gets a fatal signal security/brute: Define a LSM and manage statistical data securtiy/brute: Detect a brute force attack security/brute: Fine tuning the attack detection security/brute: Mitigate a brute force attack selftests/brute: Add tests for the Brute LSM Documentation: Add documentation for the Brute LSM MAINTAINERS: Add a new entry for the Brute LSM Documentation/admin-guide/LSM/Brute.rst | 278 ++++++ Documentation/admin-guide/LSM/index.rst | 1 + MAINTAINERS | 7 + include/linux/lsm_hook_defs.h | 1 + include/linux/lsm_hooks.h | 4 + include/linux/security.h | 4 + kernel/signal.c | 1 + security/Kconfig | 11 +- security/Makefile | 4 + security/brute/Kconfig | 13 + security/brute/Makefile | 2 + security/brute/brute.c | 1107 ++++++++++++++++++++++ security/security.c | 5 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/brute/.gitignore | 2 + tools/testing/selftests/brute/Makefile | 5 + tools/testing/selftests/brute/config | 1 + tools/testing/selftests/brute/exec.c | 44 + tools/testing/selftests/brute/test.c | 507 ++++++++++ tools/testing/selftests/brute/test.sh | 226 +++++ 20 files changed, 2219 insertions(+), 5 deletions(-) create mode 100644 Documentation/admin-guide/LSM/Brute.rst create mode 100644 security/brute/Kconfig create mode 100644 security/brute/Makefile create mode 100644 security/brute/brute.c create mode 100644 tools/testing/selftests/brute/.gitignore create mode 100644 tools/testing/selftests/brute/Makefile create mode 100644 tools/testing/selftests/brute/config create mode 100644 tools/testing/selftests/brute/exec.c create mode 100644 tools/testing/selftests/brute/test.c create mode 100755 tools/testing/selftests/brute/test.sh -- 2.25.1

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