- 19 Jan, 2023 14 commits
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Peter Xu authored
Patch series "mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare", v4. Problem ======= huge_pte_offset() is a major helper used by hugetlb code paths to walk a hugetlb pgtable. It's used mostly everywhere since that's needed even before taking the pgtable lock. huge_pte_offset() is always called with mmap lock held with either read or write. It was assumed to be safe but it's actually not. One race condition can easily trigger by: (1) firstly trigger pmd share on a memory range, (2) do huge_pte_offset() on the range, then at the meantime, (3) another thread unshare the pmd range, and the pgtable page is prone to lost if the other shared process wants to free it completely (by either munmap or exit mm). The recent work from Mike on vma lock can resolve most of this already. It's achieved by forbidden pmd unsharing during the lock being taken, so no further risk of the pgtable page being freed. It means if we can take the vma lock around all huge_pte_offset() callers it'll be safe. There're already a bunch of them that we did as per the latest mm-unstable, but also quite a few others that we didn't for various reasons especially on huge_pte_offset() usage. One more thing to mention is that besides the vma lock, i_mmap_rwsem can also be used to protect the pgtable page (along with its pgtable lock) from being freed from under us. IOW, huge_pte_offset() callers need to either hold the vma lock or i_mmap_rwsem to safely walk the pgtables. A reproducer of such problem, based on hugetlb GUP (NOTE: since the race is very hard to trigger, one needs to apply another kernel delay patch too, see below): ======8<======= #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <unistd.h> #include <sys/mman.h> #include <fcntl.h> #include <linux/memfd.h> #include <assert.h> #include <pthread.h> #define MSIZE (1UL << 30) /* 1GB */ #define PSIZE (2UL << 20) /* 2MB */ #define HOLD_SEC (1) int pipefd[2]; void *buf; void *do_map(int fd) { unsigned char *tmpbuf, *p; int ret; ret = posix_memalign((void **)&tmpbuf, MSIZE, MSIZE); if (ret) { perror("posix_memalign() failed"); return NULL; } tmpbuf = mmap(tmpbuf, MSIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, fd, 0); if (tmpbuf == MAP_FAILED) { perror("mmap() failed"); return NULL; } printf("mmap() -> %p\n", tmpbuf); for (p = tmpbuf; p < tmpbuf + MSIZE; p += PSIZE) { *p = 1; } return tmpbuf; } void do_unmap(void *buf) { munmap(buf, MSIZE); } void proc2(int fd) { unsigned char c; buf = do_map(fd); if (!buf) return; read(pipefd[0], &c, 1); /* * This frees the shared pgtable page, causing use-after-free in * proc1_thread1 when soft walking hugetlb pgtable. */ do_unmap(buf); printf("Proc2 quitting\n"); } void *proc1_thread1(void *data) { /* * Trigger follow-page on 1st 2m page. Kernel hack patch needed to * withhold this procedure for easier reproduce. */ madvise(buf, PSIZE, MADV_POPULATE_WRITE); printf("Proc1-thread1 quitting\n"); return NULL; } void *proc1_thread2(void *data) { unsigned char c; /* Wait a while until proc1_thread1() start to wait */ sleep(0.5); /* Trigger pmd unshare */ madvise(buf, PSIZE, MADV_DONTNEED); /* Kick off proc2 to release the pgtable */ write(pipefd[1], &c, 1); printf("Proc1-thread2 quitting\n"); return NULL; } void proc1(int fd) { pthread_t tid1, tid2; int ret; buf = do_map(fd); if (!buf) return; ret = pthread_create(&tid1, NULL, proc1_thread1, NULL); assert(ret == 0); ret = pthread_create(&tid2, NULL, proc1_thread2, NULL); assert(ret == 0); /* Kick the child to share the PUD entry */ pthread_join(tid1, NULL); pthread_join(tid2, NULL); do_unmap(buf); } int main(void) { int fd, ret; fd = memfd_create("test-huge", MFD_HUGETLB | MFD_HUGE_2MB); if (fd < 0) { perror("open failed"); return -1; } ret = ftruncate(fd, MSIZE); if (ret) { perror("ftruncate() failed"); return -1; } ret = pipe(pipefd); if (ret) { perror("pipe() failed"); return -1; } if (fork()) { proc1(fd); } else { proc2(fd); } close(pipefd[0]); close(pipefd[1]); close(fd); return 0; } ======8<======= The kernel patch needed to present such a race so it'll trigger 100%: ======8<======= : diff --git a/mm/hugetlb.c b/mm/hugetlb.c : index 9d97c9a2a15d..f8d99dad5004 100644 : --- a/mm/hugetlb.c : +++ b/mm/hugetlb.c : @@ -38,6 +38,7 @@ : #include <asm/page.h> : #include <asm/pgalloc.h> : #include <asm/tlb.h> : +#include <asm/delay.h> : : #include <linux/io.h> : #include <linux/hugetlb.h> : @@ -6290,6 +6291,7 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, : bool unshare = false; : int absent; : struct page *page; : + unsigned long c = 0; : : /* : * If we have a pending SIGKILL, don't keep faulting pages and : @@ -6309,6 +6311,13 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, : */ : pte = huge_pte_offset(mm, vaddr & huge_page_mask(h), : huge_page_size(h)); : + : + pr_info("%s: withhold 1 sec...\n", __func__); : + for (c = 0; c < 100; c++) { : + udelay(10000); : + } : + pr_info("%s: withhold 1 sec...done\n", __func__); : + : if (pte) : ptl = huge_pte_lock(h, mm, pte); : absent = !pte || huge_pte_none(huge_ptep_get(pte)); : ======8<======= It'll trigger use-after-free of the pgtable spinlock: ======8<======= [ 16.959907] follow_hugetlb_page: withhold 1 sec... [ 17.960315] follow_hugetlb_page: withhold 1 sec...done [ 17.960550] ------------[ cut here ]------------ [ 17.960742] DEBUG_LOCKS_WARN_ON(1) [ 17.960756] WARNING: CPU: 3 PID: 542 at kernel/locking/lockdep.c:231 __lock_acquire+0x955/0x1fa0 [ 17.961264] Modules linked in: [ 17.961394] CPU: 3 PID: 542 Comm: hugetlb-pmd-sha Not tainted 6.1.0-rc4-peterx+ #46 [ 17.961704] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 17.962266] RIP: 0010:__lock_acquire+0x955/0x1fa0 [ 17.962516] Code: c0 0f 84 5f fe ff ff 44 8b 1d 0f 9a 29 02 45 85 db 0f 85 4f fe ff ff 48 c7 c6 75 50 83 82 48 c7 c7 1b 4b 7d 82 e8 d3 22 d8 00 <0f> 0b 31 c0 4c 8b 54 24 08 4c 8b 04 24 e9 [ 17.963494] RSP: 0018:ffffc90000e4fba8 EFLAGS: 00010096 [ 17.963704] RAX: 0000000000000016 RBX: fffffffffd3925a8 RCX: 0000000000000000 [ 17.963989] RDX: 0000000000000002 RSI: ffffffff82863ccf RDI: 00000000ffffffff [ 17.964276] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffc90000e4fa58 [ 17.964557] R10: 0000000000000003 R11: ffffffff83162688 R12: 0000000000000000 [ 17.964839] R13: 0000000000000001 R14: ffff888105eac748 R15: 0000000000000001 [ 17.965123] FS: 00007f17c0a00640(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000 [ 17.965443] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 17.965672] CR2: 00007f17c09ffef8 CR3: 000000010c87a005 CR4: 0000000000770ee0 [ 17.965956] PKRU: 55555554 [ 17.966068] Call Trace: [ 17.966172] <TASK> [ 17.966268] ? tick_nohz_tick_stopped+0x12/0x30 [ 17.966455] lock_acquire+0xbf/0x2b0 [ 17.966603] ? follow_hugetlb_page.cold+0x75/0x5c4 [ 17.966799] ? _printk+0x48/0x4e [ 17.966934] _raw_spin_lock+0x2f/0x40 [ 17.967087] ? follow_hugetlb_page.cold+0x75/0x5c4 [ 17.967285] follow_hugetlb_page.cold+0x75/0x5c4 [ 17.967473] __get_user_pages+0xbb/0x620 [ 17.967635] faultin_vma_page_range+0x9a/0x100 [ 17.967817] madvise_vma_behavior+0x3c0/0xbd0 [ 17.967998] ? mas_prev+0x11/0x290 [ 17.968141] ? find_vma_prev+0x5e/0xa0 [ 17.968304] ? madvise_vma_anon_name+0x70/0x70 [ 17.968486] madvise_walk_vmas+0xa9/0x120 [ 17.968650] do_madvise.part.0+0xfa/0x270 [ 17.968813] __x64_sys_madvise+0x5a/0x70 [ 17.968974] do_syscall_64+0x37/0x90 [ 17.969123] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 17.969329] RIP: 0033:0x7f1840f0efdb [ 17.969477] Code: c3 66 0f 1f 44 00 00 48 8b 15 39 6e 0e 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa b8 1c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d 68 [ 17.970205] RSP: 002b:00007f17c09ffe38 EFLAGS: 00000202 ORIG_RAX: 000000000000001c [ 17.970504] RAX: ffffffffffffffda RBX: 00007f17c0a00640 RCX: 00007f1840f0efdb [ 17.970786] RDX: 0000000000000017 RSI: 0000000000200000 RDI: 00007f1800000000 [ 17.971068] RBP: 00007f17c09ffe50 R08: 0000000000000000 R09: 00007ffd3954164f [ 17.971353] R10: 00007f1840e10348 R11: 0000000000000202 R12: ffffffffffffff80 [ 17.971709] R13: 0000000000000000 R14: 00007ffd39541550 R15: 00007f17c0200000 [ 17.972083] </TASK> [ 17.972199] irq event stamp: 2353 [ 17.972372] hardirqs last enabled at (2353): [<ffffffff8117fe4e>] __up_console_sem+0x5e/0x70 [ 17.972869] hardirqs last disabled at (2352): [<ffffffff8117fe33>] __up_console_sem+0x43/0x70 [ 17.973365] softirqs last enabled at (2330): [<ffffffff810f763d>] __irq_exit_rcu+0xed/0x160 [ 17.973857] softirqs last disabled at (2323): [<ffffffff810f763d>] __irq_exit_rcu+0xed/0x160 [ 17.974341] ---[ end trace 0000000000000000 ]--- [ 17.974614] BUG: kernel NULL pointer dereference, address: 00000000000000b8 [ 17.975012] #PF: supervisor read access in kernel mode [ 17.975314] #PF: error_code(0x0000) - not-present page [ 17.975615] PGD 103f7b067 P4D 103f7b067 PUD 106cd7067 PMD 0 [ 17.975943] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 17.976197] CPU: 3 PID: 542 Comm: hugetlb-pmd-sha Tainted: G W 6.1.0-rc4-peterx+ #46 [ 17.976712] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 17.977370] RIP: 0010:__lock_acquire+0x190/0x1fa0 [ 17.977655] Code: 98 00 00 00 41 89 46 24 81 e2 ff 1f 00 00 48 0f a3 15 e4 ba dd 02 0f 83 ff 05 00 00 48 8d 04 52 48 c1 e0 06 48 05 c0 d2 f4 83 <44> 0f b6 a0 b8 00 00 00 41 0f b7 46 20 6f [ 17.979170] RSP: 0018:ffffc90000e4fba8 EFLAGS: 00010046 [ 17.979787] RAX: 0000000000000000 RBX: fffffffffd3925a8 RCX: 0000000000000000 [ 17.980838] RDX: 0000000000000002 RSI: ffffffff82863ccf RDI: 00000000ffffffff [ 17.982048] RBP: 0000000000000000 R08: ffff888105eac720 R09: ffffc90000e4fa58 [ 17.982892] R10: ffff888105eab900 R11: ffffffff83162688 R12: 0000000000000000 [ 17.983771] R13: 0000000000000001 R14: ffff888105eac748 R15: 0000000000000001 [ 17.984815] FS: 00007f17c0a00640(0000) GS:ffff888277cc0000(0000) knlGS:0000000000000000 [ 17.985924] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 17.986265] CR2: 00000000000000b8 CR3: 000000010c87a005 CR4: 0000000000770ee0 [ 17.986674] PKRU: 55555554 [ 17.986832] Call Trace: [ 17.987012] <TASK> [ 17.987266] ? tick_nohz_tick_stopped+0x12/0x30 [ 17.987770] lock_acquire+0xbf/0x2b0 [ 17.988118] ? follow_hugetlb_page.cold+0x75/0x5c4 [ 17.988575] ? _printk+0x48/0x4e [ 17.988889] _raw_spin_lock+0x2f/0x40 [ 17.989243] ? follow_hugetlb_page.cold+0x75/0x5c4 [ 17.989687] follow_hugetlb_page.cold+0x75/0x5c4 [ 17.990119] __get_user_pages+0xbb/0x620 [ 17.990500] faultin_vma_page_range+0x9a/0x100 [ 17.990928] madvise_vma_behavior+0x3c0/0xbd0 [ 17.991354] ? mas_prev+0x11/0x290 [ 17.991678] ? find_vma_prev+0x5e/0xa0 [ 17.992024] ? madvise_vma_anon_name+0x70/0x70 [ 17.992421] madvise_walk_vmas+0xa9/0x120 [ 17.992793] do_madvise.part.0+0xfa/0x270 [ 17.993166] __x64_sys_madvise+0x5a/0x70 [ 17.993539] do_syscall_64+0x37/0x90 [ 17.993879] entry_SYSCALL_64_after_hwframe+0x63/0xcd ======8<======= Resolution ========== This patchset protects all the huge_pte_offset() callers to also take the vma lock properly. Patch Layout ============ Patch 1-2: cleanup, or dependency of the follow up patches Patch 3: before fixing, document huge_pte_offset() on lock required Patch 4-8: each patch resolves one possible race condition Patch 9: introduce hugetlb_walk() to replace huge_pte_offset() Tests ===== The series is verified with the above reproducer so the race cannot trigger anymore. It also passes all hugetlb kselftests. This patch (of 9): Even though vma_offset_start() is named like that, it's not returning "the start address of the range" but rather the offset we should use to offset the vma->vm_start address. Make it return the real value of the start vaddr, and it also helps for all the callers because whenever the retval is used, it'll be ultimately added into the vma->vm_start anyway, so it's better. Link: https://lkml.kernel.org/r/20221216155100.2043537-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20221216155100.2043537-2-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Jann Horn <jannh@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mike Kravetz authored
The check for whether a hugetlb vma lock exists partially depends on the vma's flags. Currently, it checks for either VM_MAYSHARE or VM_SHARED. The reason both flags are used is because VM_MAYSHARE was previously cleared in hugetlb vmas as they are tore down. This is no longer the case, and only the VM_MAYSHARE check is required. Link: https://lkml.kernel.org/r/20221212235042.178355-2-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Jeff Xu authored
Tests to verify MFD_NOEXEC, MFD_EXEC and vm.memfd_noexec sysctl. Link: https://lkml.kernel.org/r/20221215001205.51969-6-jeffxu@google.comSigned-off-by: Jeff Xu <jeffxu@google.com> Co-developed-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: kernel test robot <lkp@intel.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Jeff Xu authored
In order to avoid WX mappings, add F_SEAL_WRITE when apply F_SEAL_EXEC to an executable memfd, so W^X from start. This implys application need to fill the content of the memfd first, after F_SEAL_EXEC is applied, application can no longer modify the content of the memfd. Typically, application seals the memfd right after writing to it. For example: 1. memfd_create(MFD_EXEC). 2. write() code to the memfd. 3. fcntl(F_ADD_SEALS, F_SEAL_EXEC) to convert the memfd to W^X. 4. call exec() on the memfd. Link: https://lkml.kernel.org/r/20221215001205.51969-5-jeffxu@google.comSigned-off-by: Jeff Xu <jeffxu@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Daniel Verkamp <dverkamp@chromium.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: kernel test robot <lkp@intel.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Jeff Xu authored
The new MFD_NOEXEC_SEAL and MFD_EXEC flags allows application to set executable bit at creation time (memfd_create). When MFD_NOEXEC_SEAL is set, memfd is created without executable bit (mode:0666), and sealed with F_SEAL_EXEC, so it can't be chmod to be executable (mode: 0777) after creation. when MFD_EXEC flag is set, memfd is created with executable bit (mode:0777), this is the same as the old behavior of memfd_create. The new pid namespaced sysctl vm.memfd_noexec has 3 values: 0: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like MFD_EXEC was set. 1: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like MFD_NOEXEC_SEAL was set. 2: memfd_create() without MFD_NOEXEC_SEAL will be rejected. The sysctl allows finer control of memfd_create for old-software that doesn't set the executable bit, for example, a container with vm.memfd_noexec=1 means the old-software will create non-executable memfd by default. Also, the value of memfd_noexec is passed to child namespace at creation time. For example, if the init namespace has vm.memfd_noexec=2, all its children namespaces will be created with 2. [akpm@linux-foundation.org: add stub functions to fix build] [akpm@linux-foundation.org: remove unneeded register_pid_ns_ctl_table_vm() stub, per Jeff] [akpm@linux-foundation.org: s/pr_warn_ratelimited/pr_warn_once/, per review] [akpm@linux-foundation.org: fix CONFIG_SYSCTL=n warning] Link: https://lkml.kernel.org/r/20221215001205.51969-4-jeffxu@google.comSigned-off-by: Jeff Xu <jeffxu@google.com> Co-developed-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Daniel Verkamp authored
Basic tests to ensure that user/group/other execute bits cannot be changed after applying F_SEAL_EXEC to a memfd. Link: https://lkml.kernel.org/r/20221215001205.51969-3-jeffxu@google.comSigned-off-by: Daniel Verkamp <dverkamp@chromium.org> Co-developed-by: Jeff Xu <jeffxu@google.com> Signed-off-by: Jeff Xu <jeffxu@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: kernel test robot <lkp@intel.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Daniel Verkamp authored
Patch series "mm/memfd: introduce MFD_NOEXEC_SEAL and MFD_EXEC", v8. Since Linux introduced the memfd feature, memfd have always had their execute bit set, and the memfd_create() syscall doesn't allow setting it differently. However, in a secure by default system, such as ChromeOS, (where all executables should come from the rootfs, which is protected by Verified boot), this executable nature of memfd opens a door for NoExec bypass and enables “confused deputy attack”. E.g, in VRP bug [1]: cros_vm process created a memfd to share the content with an external process, however the memfd is overwritten and used for executing arbitrary code and root escalation. [2] lists more VRP in this kind. On the other hand, executable memfd has its legit use, runc uses memfd’s seal and executable feature to copy the contents of the binary then execute them, for such system, we need a solution to differentiate runc's use of executable memfds and an attacker's [3]. To address those above, this set of patches add following: 1> Let memfd_create() set X bit at creation time. 2> Let memfd to be sealed for modifying X bit. 3> A new pid namespace sysctl: vm.memfd_noexec to control the behavior of X bit.For example, if a container has vm.memfd_noexec=2, then memfd_create() without MFD_NOEXEC_SEAL will be rejected. 4> A new security hook in memfd_create(). This make it possible to a new LSM, which rejects or allows executable memfd based on its security policy. This patch (of 5): The new F_SEAL_EXEC flag will prevent modification of the exec bits: written as traditional octal mask, 0111, or as named flags, S_IXUSR | S_IXGRP | S_IXOTH. Any chmod(2) or similar call that attempts to modify any of these bits after the seal is applied will fail with errno EPERM. This will preserve the execute bits as they are at the time of sealing, so the memfd will become either permanently executable or permanently un-executable. Link: https://lkml.kernel.org/r/20221215001205.51969-1-jeffxu@google.com Link: https://lkml.kernel.org/r/20221215001205.51969-2-jeffxu@google.comSigned-off-by: Daniel Verkamp <dverkamp@chromium.org> Co-developed-by: Jeff Xu <jeffxu@google.com> Signed-off-by: Jeff Xu <jeffxu@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Peter Xu authored
This patch is a cleanup to always wr-protect pte/pmd in mkuffd_wp paths. The reasons I still think this patch is worthwhile, are: (1) It is a cleanup already; diffstat tells. (2) It just feels natural after I thought about this, if the pte is uffd protected, let's remove the write bit no matter what it was. (2) Since x86 is the only arch that supports uffd-wp, it also redefines pte|pmd_mkuffd_wp() in that it should always contain removals of write bits. It means any future arch that want to implement uffd-wp should naturally follow this rule too. It's good to make it a default, even if with vm_page_prot changes on VM_UFFD_WP. (3) It covers more than vm_page_prot. So no chance of any potential future "accident" (like pte_mkdirty() sparc64 or loongarch, even though it just got its pte_mkdirty fixed <1 month ago). It'll be fairly clear when reading the code too that we don't worry anything before a pte_mkuffd_wp() on uncertainty of the write bit. We may call pte_wrprotect() one more time in some paths (e.g. thp split), but that should be fully local bitop instruction so the overhead should be negligible. Although this patch should logically also fix all the known issues on uffd-wp too recently on page migration (not for numa hint recovery - that may need another explcit pte_wrprotect), but this is not the plan for that fix. So no fixes, and stable doesn't need this. Link: https://lkml.kernel.org/r/20221214201533.1774616-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ives van Hoorne <ives@codesandbox.io> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Sidhartha Kumar authored
folio_set_compound_order() is moved to an mm-internal location so external folio users cannot misuse this function. Change the name of the function to folio_set_order() and use WARN_ON_ONCE() rather than BUG_ON. Also, handle the case if a non-large folio is passed and add clarifying comments to the function. Link: https://lore.kernel.org/lkml/20221207223731.32784-1-sidhartha.kumar@oracle.com/T/ Link: https://lkml.kernel.org/r/20221215061757.223440-1-sidhartha.kumar@oracle.com Fixes: 9fd33058 ("mm: add folio dtor and order setter functions") Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Suggested-by: Muchun Song <songmuchun@bytedance.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Andrew Morton authored
Merge branch 'mm-hotfixes-stable' into mm-stable
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Peter Xu authored
This patch should harden commit 15520a3f ("mm: use pte markers for swap errors") on using pte markers for swapin errors on a few corner cases. 1. Propagate swapin errors across fork()s: if there're swapin errors in the parent mm, after fork()s the child should sigbus too when an error page is accessed. 2. Fix a rare condition race in pte_marker_clear() where a uffd-wp pte marker can be quickly switched to a swapin error. 3. Explicitly ignore swapin error pte markers in change_protection(). I mostly don't worry on (2) or (3) at all, but we should still have them. Case (1) is special because it can potentially cause silent data corrupt on child when parent has swapin error triggered with swapoff, but since swapin error is rare itself already it's probably not easy to trigger either. Currently there is a priority difference between the uffd-wp bit and the swapin error entry, in which the swapin error always has higher priority (e.g. we don't need to wr-protect a swapin error pte marker). If there will be a 3rd bit introduced, we'll probably need to consider a more involved approach so we may need to start operate on the bits. Let's leave that for later. This patch is tested with case (1) explicitly where we'll get corrupted data before in the child if there's existing swapin error pte markers, and after patch applied the child can be rightfully killed. We don't need to copy stable for this one since 15520a3f just landed as part of v6.2-rc1, only "Fixes" applied. Link: https://lkml.kernel.org/r/20221214200453.1772655-3-peterx@redhat.com Fixes: 15520a3f ("mm: use pte markers for swap errors") Signed-off-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Pengfei Xu <pengfei.xu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Peter Xu authored
Patch series "mm: Fixes on pte markers". Patch 1 resolves the syzkiller report from Pengfei. Patch 2 further harden pte markers when used with the recent swapin error markers. The major case is we should persist a swapin error marker after fork(), so child shouldn't read a corrupted page. This patch (of 2): When fork(), dst_vma is not guaranteed to have VM_UFFD_WP even if src may have it and has pte marker installed. The warning is improper along with the comment. The right thing is to inherit the pte marker when needed, or keep the dst pte empty. A vague guess is this happened by an accident when there's the prior patch to introduce src/dst vma into this helper during the uffd-wp feature got developed and I probably messed up in the rebase, since if we replace dst_vma with src_vma the warning & comment it all makes sense too. Hugetlb did exactly the right here (copy_hugetlb_page_range()). Fix the general path. Reproducer: https://github.com/xupengfe/syzkaller_logs/blob/main/221208_115556_copy_page_range/repro.c Bugzilla report: https://bugzilla.kernel.org/show_bug.cgi?id=216808 Link: https://lkml.kernel.org/r/20221214200453.1772655-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20221214200453.1772655-2-peterx@redhat.com Fixes: c56d1b62 ("mm/shmem: handle uffd-wp during fork()") Signed-off-by: Peter Xu <peterx@redhat.com> Reported-by: Pengfei Xu <pengfei.xu@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: <stable@vger.kernel.org> # 5.19+ Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Andrew Morton authored
Merge branch 'master' into mm-hotfixes-stable
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Andrew Morton authored
Merge branch 'master' into mm-stable
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- 15 Jan, 2023 4 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Borislav Petkov: - Make sure the poking PGD is pinned for Xen PV as it requires it this way - Fixes for two resctrl races when moving a task or creating a new monitoring group - Fix SEV-SNP guests running under HyperV where MTRRs are disabled to not return a UC- type mapping type on memremap() and thus cause a serious slowdown - Fix insn mnemonics in bioscall.S now that binutils is starting to fix confusing insn suffixes * tag 'x86_urgent_for_v6.2_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: fix poking_init() for Xen PV guests x86/resctrl: Fix event counts regression in reused RMIDs x86/resctrl: Fix task CLOSID/RMID update race x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case x86/boot: Avoid using Intel mnemonics in AT&T syntax asm
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git://git.kernel.org/pub/scm/linux/kernel/git/ras/rasLinus Torvalds authored
Pull EDAC fixes from Borislav Petkov: - Fix the EDAC device's confusion in the polling setting units - Fix a memory leak in highbank's probing function * tag 'edac_urgent_for_v6.2_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: EDAC/highbank: Fix memory leak in highbank_mc_probe() EDAC/device: Fix period calculation in edac_device_reset_delay_period()
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Michael Ellerman: - Fix a build failure with some versions of ld that have an odd version string - Fix incorrect use of mutex in the IMC PMU driver Thanks to Kajol Jain, Michael Petlan, Ojaswin Mujoo, Peter Zijlstra, and Yang Yingliang. * tag 'powerpc-6.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s/hash: Make stress_hpt_timer_fn() static powerpc/imc-pmu: Fix use of mutex in IRQs disabled section powerpc/boot: Fix incorrect version calculation issue in ld_version
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- 14 Jan, 2023 7 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommuLinus Torvalds authored
Pull iommu fixes from Joerg Roedel: - Core: Fix an iommu-group refcount leak - Fix overflow issue in IOVA alloc path - ARM-SMMU fixes from Will: - Fix VFIO regression on NXP SoCs by reporting IOMMU_CAP_CACHE_COHERENCY - Fix SMMU shutdown paths to avoid device unregistration race - Error handling fix for Mediatek IOMMU driver * tag 'iommu-fixes-v6.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/mediatek-v1: Fix an error handling path in mtk_iommu_v1_probe() iommu/iova: Fix alloc iova overflows issue iommu: Fix refcount leak in iommu_device_claim_dma_owner iommu/arm-smmu-v3: Don't unregister on shutdown iommu/arm-smmu: Don't unregister on shutdown iommu/arm-smmu: Report IOMMU_CAP_CACHE_COHERENCY even betterer
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git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblockLinus Torvalds authored
Pull memblock fix from Mike Rapoport: "memblock: always release pages to the buddy allocator in memblock_free_late() If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages() only releases pages to the buddy allocator if they are not in the deferred range. This is correct for free pages (as defined by for_each_free_mem_pfn_range_in_zone()) because free pages in the deferred range will be initialized and released as part of the deferred init process. memblock_free_pages() is called by memblock_free_late(), which is used to free reserved ranges after memblock_free_all() has run. All pages in reserved ranges have been initialized at that point, and accordingly, those pages are not touched by the deferred init process. This means that currently, if the pages that memblock_free_late() intends to release are in the deferred range, they will never be released to the buddy allocator. They will forever be reserved. In addition, memblock_free_pages() calls kmsan_memblock_free_pages(), which is also correct for free pages but is not correct for reserved pages. KMSAN metadata for reserved pages is initialized by kmsan_init_shadow(), which runs shortly before memblock_free_all(). For both of these reasons, memblock_free_pages() should only be called for free pages, and memblock_free_late() should call __free_pages_core() directly instead. One case where this issue can occur in the wild is EFI boot on x86_64. The x86 EFI code reserves all EFI boot services memory ranges via memblock_reserve() and frees them later via memblock_free_late() (efi_reserve_boot_services() and efi_free_boot_services(), respectively). If any of those ranges happens to fall within the deferred init range, the pages will not be released and that memory will be unavailable. For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI: v6.2-rc2: Node 0, zone DMA spanned 4095 present 3999 managed 3840 Node 0, zone DMA32 spanned 246652 present 245868 managed 178867 v6.2-rc2 + patch: Node 0, zone DMA spanned 4095 present 3999 managed 3840 Node 0, zone DMA32 spanned 246652 present 245868 managed 222816 # +43,949 pages" * tag 'fixes-2023-01-14' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: mm: Always release pages to the buddy allocator in memblock_free_late().
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linuxLinus Torvalds authored
Pull kernel hardening fixes from Kees Cook: - Fix CFI hash randomization with KASAN (Sami Tolvanen) - Check size of coreboot table entry and use flex-array * tag 'hardening-v6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: Fix CFI hash randomization with KASAN firmware: coreboot: Check size of table entry and use flex-array
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git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linuxLinus Torvalds authored
Pull module fix from Luis Chamberlain: "Just one fix for modules by Nick" * tag 'modules-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: kallsyms: Fix scheduling with interrupts disabled in self-test
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git://git.samba.org/sfrench/cifs-2.6Linus Torvalds authored
Pull cifs fixes from Steve French: - memory leak and double free fix - two symlink fixes - minor cleanup fix - two smb1 fixes * tag '6.2-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: Fix uninitialized memory read for smb311 posix symlink create cifs: fix potential memory leaks in session setup cifs: do not query ifaces on smb1 mounts cifs: fix double free on failed kerberos auth cifs: remove redundant assignment to the variable match cifs: fix file info setting in cifs_open_file() cifs: fix file info setting in cifs_query_path_info()
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Two minor fixes in the hisi_sas driver which only impact enterprise style multi-expander and shared disk situations and no core changes" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: hisi_sas: Set a port invalid only if there are no devices attached when refreshing port id scsi: hisi_sas: Use abort task set to reset SAS disks when discovered
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git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libataLinus Torvalds authored
Pull ATA fix from Damien Le Moal: "A single fix to prevent building the pata_cs5535 driver with user mode linux as it uses msr operations that are not defined with UML" * tag 'ata-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata: ata: pata_cs5535: Don't build on UML
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- 13 Jan, 2023 15 commits
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git://git.kernel.dk/linuxLinus Torvalds authored
Pull block fixes from Jens Axboe: "Nothing major in here, just a collection of NVMe fixes and dropping a wrong might_sleep() that static checkers tripped over but which isn't valid" * tag 'block-6.2-2023-01-13' of git://git.kernel.dk/linux: MAINTAINERS: stop nvme matching for nvmem files nvme: don't allow unprivileged passthrough on partitions nvme: replace the "bool vec" arguments with flags in the ioctl path nvme: remove __nvme_ioctl nvme-pci: fix error handling in nvme_pci_enable() nvme-pci: add NVME_QUIRK_IDENTIFY_CNS quirk to Apple T2 controllers nvme-apple: add NVME_QUIRK_IDENTIFY_CNS quirk to fix regression block: Drop spurious might_sleep() from blk_put_queue()
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git://git.kernel.dk/linuxLinus Torvalds authored
Pull io_uring fixes from Jens Axboe: "A fix for a regression that happened last week, rest is fixes that will be headed to stable as well. In detail: - Fix for a regression added with the leak fix from last week (me) - In writing a test case for that leak, inadvertently discovered a case where we a poll request can race. So fix that up and mark it for stable, and also ensure that fdinfo covers both the poll tables that we have. The latter was an oversight when the split poll table were added (me) - Fix for a lockdep reported issue with IOPOLL (Pavel)" * tag 'io_uring-6.2-2023-01-13' of git://git.kernel.dk/linux: io_uring: lock overflowing for IOPOLL io_uring/poll: attempt request issue after racy poll wakeup io_uring/fdinfo: include locked hash table in fdinfo output io_uring/poll: add hash if ready poll request can't complete inline io_uring/io-wq: only free worker if it was allocated for creation
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull pci fixes from Bjorn Helgaas: - Work around apparent firmware issue that made Linux reject MMCONFIG space, which broke PCI extended config space (Bjorn Helgaas) - Fix CONFIG_PCIE_BT1 dependency due to mid-air collision between a PCI_MSI_IRQ_DOMAIN -> PCI_MSI change and addition of PCIE_BT1 (Lukas Bulwahn) * tag 'pci-v6.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: x86/pci: Treat EfiMemoryMappedIO as reservation of ECAM space x86/pci: Simplify is_mmconf_reserved() messages PCI: dwc: Adjust to recent removal of PCI_MSI_IRQ_DOMAIN
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Sami Tolvanen authored
Clang emits a asan.module_ctor constructor to each object file when KASAN is enabled, and these functions are indirectly called in do_ctors. With CONFIG_CFI_CLANG, the compiler also emits a CFI type hash before each address-taken global function so they can pass indirect call checks. However, in commit 0c3e806e ("x86/cfi: Add boot time hash randomization"), x86 implemented boot time hash randomization, which relies on the .cfi_sites section generated by objtool. As objtool is run against vmlinux.o instead of individual object files with X86_KERNEL_IBT (enabled by default), CFI types in object files that are not part of vmlinux.o end up not being included in .cfi_sites, and thus won't get randomized and trip CFI when called. Only .vmlinux.export.o and init/version-timestamp.o are linked into vmlinux separately from vmlinux.o. As these files don't contain any functions, disable KASAN for both of them to avoid breaking hash randomization. Link: https://github.com/ClangBuiltLinux/linux/issues/1742 Fixes: 0c3e806e ("x86/cfi: Add boot time hash randomization") Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230112224948.1479453-2-samitolvanen@google.com
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Kees Cook authored
The memcpy() of the data following a coreboot_table_entry couldn't be evaluated by the compiler under CONFIG_FORTIFY_SOURCE. To make it easier to reason about, add an explicit flexible array member to struct coreboot_device so the entire entry can be copied at once. Additionally, validate the sizes before copying. Avoids this run-time false positive warning: memcpy: detected field-spanning write (size 168) of single field "&device->entry" at drivers/firmware/google/coreboot_table.c:103 (size 8) Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Link: https://lore.kernel.org/all/03ae2704-8c30-f9f0-215b-7cdf4ad35a9a@molgen.mpg.de/ Cc: Jack Rosenthal <jrosenth@chromium.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Julius Werner <jwerner@chromium.org> Cc: Brian Norris <briannorris@chromium.org> Cc: Stephen Boyd <swboyd@chromium.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Link: https://lore.kernel.org/r/20230107031406.gonna.761-kees@kernel.orgReviewed-by: Stephen Boyd <swboyd@chromium.org> Reviewed-by: Jack Rosenthal <jrosenth@chromium.org> Link: https://lore.kernel.org/r/20230112230312.give.446-kees@kernel.org
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Nicholas Piggin authored
kallsyms_on_each* may schedule so must not be called with interrupts disabled. The iteration function could disable interrupts, but this also changes lookup_symbol() to match the change to the other timing code. Reported-by: Erhard F. <erhard_f@mailbox.org> Link: https://lore.kernel.org/all/bug-216902-206035@https.bugzilla.kernel.org%2F/Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202212251728.8d0872ff-oliver.sang@intel.com Fixes: 30f3bb09 ("kallsyms: Add self-test facility") Tested-by: "Erhard F." <erhard_f@mailbox.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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Peter Foley authored
This driver uses MSR functions that aren't implemented under UML. Avoid building it to prevent tripping up allyesconfig. e.g. /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x3a3): undefined reference to `__tracepoint_read_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x3d2): undefined reference to `__tracepoint_write_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x457): undefined reference to `__tracepoint_write_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x481): undefined reference to `do_trace_write_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x4d5): undefined reference to `do_trace_write_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x4f5): undefined reference to `do_trace_read_msr' /usr/lib/gcc/x86_64-pc-linux-gnu/12/../../../../x86_64-pc-linux-gnu/bin/ld: pata_cs5535.c:(.text+0x51c): undefined reference to `do_trace_write_msr' Signed-off-by: Peter Foley <pefoley2@pefoley.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
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git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds authored
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix the PMCR_EL0 reset value after the PMU rework - Correctly handle S2 fault triggered by a S1 page table walk by not always classifying it as a write, as this breaks on R/O memslots - Document why we cannot exit with KVM_EXIT_MMIO when taking a write fault from a S1 PTW on a R/O memslot - Put the Apple M2 on the naughty list for not being able to correctly implement the vgic SEIS feature, just like the M1 before it - Reviewer updates: Alex is stepping down, replaced by Zenghui x86: - Fix various rare locking issues in Xen emulation and teach lockdep to detect them - Documentation improvements - Do not return host topology information from KVM_GET_SUPPORTED_CPUID" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86/xen: Avoid deadlock by adding kvm->arch.xen.xen_lock leaf node lock KVM: Ensure lockdep knows about kvm->lock vs. vcpu->mutex ordering rule KVM: x86/xen: Fix potential deadlock in kvm_xen_update_runstate_guest() KVM: x86/xen: Fix lockdep warning on "recursive" gpc locking Documentation: kvm: fix SRCU locking order docs KVM: x86: Do not return host topology information from KVM_GET_SUPPORTED_CPUID KVM: nSVM: clarify recalc_intercepts() wrt CR8 MAINTAINERS: Remove myself as a KVM/arm64 reviewer MAINTAINERS: Add Zenghui Yu as a KVM/arm64 reviewer KVM: arm64: vgic: Add Apple M2 cpus to the list of broken SEIS implementations KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_* KVM: arm64: Document the behaviour of S1PTW faults on RO memslots KVM: arm64: Fix S1PTW handling on RO memslots KVM: arm64: PMU: Fix PMCR_EL0 reset value
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Mateusz Guzik authored
On the x86-64 architecture even a failing cmpxchg grants exclusive access to the cacheline, making it preferable to retry the failed op immediately instead of stalling with the pause instruction. To illustrate the impact, below are benchmark results obtained by running various will-it-scale tests on top of the 6.2-rc3 kernel and Cascade Lake (2 sockets * 24 cores * 2 threads) CPU. All results in ops/s. Note there is some variance in re-runs, but the code is consistently faster when contention is present. open3 ("Same file open/close"): proc stock no-pause 1 805603 814942 (+%1) 2 1054980 1054781 (-0%) 8 1544802 1822858 (+18%) 24 1191064 2199665 (+84%) 48 851582 1469860 (+72%) 96 609481 1427170 (+134%) fstat2 ("Same file fstat"): proc stock no-pause 1 3013872 3047636 (+1%) 2 4284687 4400421 (+2%) 8 3257721 5530156 (+69%) 24 2239819 5466127 (+144%) 48 1701072 5256609 (+209%) 96 1269157 6649326 (+423%) Additionally, a kernel with a private patch to help access() scalability: access2 ("Same file access"): proc stock patched patched +nopause 24 2378041 2005501 5370335 (-15% / +125%) That is, fixing the problems in access itself *reduces* scalability after the cacheline ping-pong only happens in lockref with the pause instruction. Note that fstat and access benchmarks are not currently integrated into will-it-scale, but interested parties can find them in pull requests to said project. Code at hand has a rather tortured history. First modification showed up in commit d472d9d9 ("lockref: Relax in cmpxchg loop"), written with Itanium in mind. Later it got patched up to use an arch-dependent macro to stop doing it on s390 where it caused a significant regression. Said macro had undergone revisions and was ultimately eliminated later, going back to cpu_relax. While I intended to only remove cpu_relax for x86-64, I got the following comment from Linus: I would actually prefer just removing it entirely and see if somebody else hollers. You have the numbers to prove it hurts on real hardware, and I don't think we have any numbers to the contrary. So I think it's better to trust the numbers and remove it as a failure, than say "let's just remove it on x86-64 and leave everybody else with the potentially broken code" Additionally, Will Deacon (maintainer of the arm64 port, one of the architectures previously benchmarked): So, from the arm64 side of the fence, I'm perfectly happy just removing the cpu_relax() calls from lockref. As such, come back full circle in history and whack it altogether. Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/all/CAGudoHHx0Nqg6DE70zAVA75eV-HXfWyhVMWZ-aSeOofkA_=WdA@mail.gmail.com/ Acked-by: Tony Luck <tony.luck@intel.com> # ia64 Acked-by: Nicholas Piggin <npiggin@gmail.com> # powerpc Acked-by: Will Deacon <will@kernel.org> # arm64 Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Bjorn Helgaas authored
Normally we reject ECAM space unless it is reported as reserved in the E820 table or via a PNP0C02 _CRS method (PCI Firmware, r3.3, sec 4.1.2). 07eab090 ("efi/x86: Remove EfiMemoryMappedIO from E820 map"), removes E820 entries that correspond to EfiMemoryMappedIO regions because some other firmware uses EfiMemoryMappedIO for PCI host bridge windows, and the E820 entries prevent Linux from allocating BAR space for hot-added devices. Some firmware doesn't report ECAM space via PNP0C02 _CRS methods, but does mention it as an EfiMemoryMappedIO region via EFI GetMemoryMap(), which is normally converted to an E820 entry by a bootloader or EFI stub. After 07eab090, that E820 entry is removed, so we reject this ECAM space, which makes PCI extended config space (offsets 0x100-0xfff) inaccessible. The lack of extended config space breaks anything that relies on it, including perf, VSEC telemetry, EDAC, QAT, SR-IOV, etc. Allow use of ECAM for extended config space when the region is covered by an EfiMemoryMappedIO region, even if it's not included in E820 or PNP0C02 _CRS. Link: https://lore.kernel.org/r/ac2693d8-8ba3-72e0-5b66-b3ae008d539d@linux.intel.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=216891 Fixes: 07eab090 ("efi/x86: Remove EfiMemoryMappedIO from E820 map") Link: https://lore.kernel.org/r/20230110180243.1590045-3-helgaas@kernel.orgReported-by: Kan Liang <kan.liang@linux.intel.com> Reported-by: Tony Luck <tony.luck@intel.com> Reported-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Reported-by: Yunying Sun <yunying.sun@intel.com> Reported-by: Baowen Zheng <baowen.zheng@corigine.com> Reported-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reported-by: Yang Lixiao <lixiao.yang@intel.com> Tested-by: Tony Luck <tony.luck@intel.com> Tested-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com> Tested-by: Kan Liang <kan.liang@linux.intel.com> Tested-by: Yunying Sun <yunying.sun@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/efi/efiLinus Torvalds authored
Pull EFI fixes from Ard Biesheuvel: - avoid a potential crash on the efi_subsys_init() error path - use more appropriate error code for runtime services calls issued after a crash in the firmware occurred - avoid READ_ONCE() for accessing firmware tables that may appear misaligned in memory * tag 'efi-fixes-for-v6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: efi: tpm: Avoid READ_ONCE() for accessing the event log efi: rt-wrapper: Add missing include efi: fix userspace infinite retry read efivars after EFI runtime services page fault efi: fix NULL-deref in init error path
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git://git.lwn.net/linuxLinus Torvalds authored
Pull documentation fixes from Jonathan Corbet: "Three documentation fixes (or rather two and one warning): - Sphinx 6.0 broke our configuration mechanism, so fix it - I broke our configuration for non-Alabaster themes; Akira fixed it - Deprecate Sphinx < 2.4 with an eye toward future removal" * tag 'docs-6.2-fixes' of git://git.lwn.net/linux: docs/conf.py: Use about.html only in sidebar of alabaster theme docs: Deprecate use of Sphinx < 2.4.x docs: Fix the docs build with Sphinx 6.0
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Ard Biesheuvel authored
Nathan reports that recent kernels built with LTO will crash when doing EFI boot using Fedora's GRUB and SHIM. The culprit turns out to be a misaligned load from the TPM event log, which is annotated with READ_ONCE(), and under LTO, this gets translated into a LDAR instruction which does not tolerate misaligned accesses. Interestingly, this does not happen when booting the same kernel straight from the UEFI shell, and so the fact that the event log may appear misaligned in memory may be caused by a bug in GRUB or SHIM. However, using READ_ONCE() to access firmware tables is slightly unusual in any case, and here, we only need to ensure that 'event' is not dereferenced again after it gets unmapped, but this is already taken care of by the implicit barrier() semantics of the early_memunmap() call. Cc: <stable@vger.kernel.org> Cc: Peter Jones <pjones@redhat.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Reported-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://github.com/ClangBuiltLinux/linux/issues/1782Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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Pavel Begunkov authored
syzbot reports an issue with overflow filling for IOPOLL: WARNING: CPU: 0 PID: 28 at io_uring/io_uring.c:734 io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 CPU: 0 PID: 28 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0 Workqueue: events_unbound io_ring_exit_work Call trace: io_cqring_event_overflow+0x1c0/0x230 io_uring/io_uring.c:734 io_req_cqe_overflow+0x5c/0x70 io_uring/io_uring.c:773 io_fill_cqe_req io_uring/io_uring.h:168 [inline] io_do_iopoll+0x474/0x62c io_uring/rw.c:1065 io_iopoll_try_reap_events+0x6c/0x108 io_uring/io_uring.c:1513 io_uring_try_cancel_requests+0x13c/0x258 io_uring/io_uring.c:3056 io_ring_exit_work+0xec/0x390 io_uring/io_uring.c:2869 process_one_work+0x2d8/0x504 kernel/workqueue.c:2289 worker_thread+0x340/0x610 kernel/workqueue.c:2436 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863 There is no real problem for normal IOPOLL as flush is also called with uring_lock taken, but it's getting more complicated for IOPOLL|SQPOLL, for which __io_cqring_overflow_flush() happens from the CQ waiting path. Reported-and-tested-by: syzbot+6805087452d72929404e@syzkaller.appspotmail.com Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/soundLinus Torvalds authored
Pull sound fixes from Takashi Iwai: "This became a slightly big update, but it's more or less expected, as the first batch after holidays. All changes (but for the last two last-minute fixes) have been stewed in linux-next long enough, so it's fairly safe to take: - PCM UAF fix in 32bit compat layer - ASoC board-specific fixes for Intel, AMD, Medathek, Qualcomm - SOF power management fixes - ASoC Intel link failure fixes - A series of fixes for USB-audio regressions - CS35L41 HD-audio codec regression fixes - HD-audio device-specific fixes / quirks Note that one SPI patch has been taken in ASoC subtree mistakenly, and the same fix is found in spi tree, but it should be OK to apply" * tag 'sound-6.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (39 commits) ALSA: pcm: Move rwsem lock inside snd_ctl_elem_read to prevent UAF ALSA: usb-audio: Fix possible NULL pointer dereference in snd_usb_pcm_has_fixed_rate() ALSA: hda/realtek: Enable mute/micmute LEDs on HP Spectre x360 13-aw0xxx ASoC: fsl-asoc-card: Fix naming of AC'97 CODEC widgets ASoC: fsl_ssi: Rename AC'97 streams to avoid collisions with AC'97 CODEC ALSA: hda/hdmi: Add a HP device 0x8715 to force connect list ALSA: control-led: use strscpy in set_led_id() ALSA: usb-audio: Always initialize fixed_rate in snd_usb_find_implicit_fb_sync_format() ASoC: dt-bindings: qcom,lpass-tx-macro: correct clocks on SC7280 ASoC: dt-bindings: qcom,lpass-wsa-macro: correct clocks on SM8250 ASoC: qcom: Fix building APQ8016 machine driver without SOUNDWIRE ALSA: hda: cs35l41: Check runtime suspend capability at runtime_idle ALSA: hda: cs35l41: Don't return -EINVAL from system suspend/resume ASoC: fsl_micfil: Correct the number of steps on SX controls ALSA: hda/realtek: fix mute/micmute LEDs don't work for a HP platform Revert "ALSA: usb-audio: Drop superfluous interface setup at parsing" ALSA: usb-audio: More refactoring of hw constraint rules ALSA: usb-audio: Relax hw constraints for implicit fb sync ALSA: usb-audio: Make sure to stop endpoints before closing EPs ALSA: hda - Enable headset mic on another Dell laptop with ALC3254 ...
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