July 2018 - Linux-stable-mirror

[PATCH] net: lan78xx: Fix race in tx pending skb size calculation

by Stefan Wahren

The skb size calculation in lan78xx_tx_bh is in race with the start_xmit, which could lead to rare kernel oopses. So protect the whole skb walk with a spin lock. As a benefit we can unlink the skb directly. This patch was tested on Raspberry Pi 3B+ Link: https://github.com/raspberrypi/linux/issues/2608 Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet") Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Floris Bos <bos(a)je-eigen-domein.nl> Signed-off-by: Stefan Wahren <stefan.wahren(a)i2se.com> --- drivers/net/usb/lan78xx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c index 2e41307..ed10d49 100644 --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -3344,6 +3344,7 @@ static void lan78xx_tx_bh(struct lan78xx_net *dev) pkt_cnt = 0; count = 0; length = 0; + spin_lock_irqsave(&tqp->lock, flags); for (skb = tqp->next; pkt_cnt < tqp->qlen; skb = skb->next) { if (skb_is_gso(skb)) { if (pkt_cnt) { @@ -3352,7 +3353,8 @@ static void lan78xx_tx_bh(struct lan78xx_net *dev) } count = 1; length = skb->len - TX_OVERHEAD; - skb2 = skb_dequeue(tqp); + __skb_unlink(skb, tqp); + spin_unlock_irqrestore(&tqp->lock, flags); goto gso_skb; } @@ -3361,6 +3363,7 @@ static void lan78xx_tx_bh(struct lan78xx_net *dev) skb_totallen = skb->len + roundup(skb_totallen, sizeof(u32)); pkt_cnt++; } + spin_unlock_irqrestore(&tqp->lock, flags); /* copy to a single skb */ skb = alloc_skb(skb_totallen, GFP_ATOMIC); -- 2.7.4

6 years, 7 months

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[merged] mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: do not bug_on on incorrect length in __mm_populate() has been removed from the -mm tree. Its filename was mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Michal Hocko <mhocko(a)suse.com> Subject: mm: do not bug_on on incorrect length in __mm_populate() syzbot has noticed that a specially crafted library can easily hit VM_BUG_ON in __mm_populate localhost login: [ 81.210241] emacs (9634) used greatest stack depth: 10416 bytes left [ 140.099935] ------------[ cut here ]------------ [ 140.101904] kernel BUG at mm/gup.c:1242! [ 140.103572] invalid opcode: 0000 [#1] SMP [ 140.105220] CPU: 2 PID: 9667 Comm: a.out Not tainted 4.18.0-rc3 #644 [ 140.107762] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 140.112000] RIP: 0010:__mm_populate+0x1e2/0x1f0 [ 140.113875] Code: 55 d0 65 48 33 14 25 28 00 00 00 89 d8 75 21 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 18 f1 ff 0f 0b e8 6e 18 f1 ff <0f> 0b 31 db eb c9 e8 93 06 e0 ff 0f 1f 00 55 48 89 e5 53 48 89 fb [ 140.121403] RSP: 0018:ffffc90000dffd78 EFLAGS: 00010293 [ 140.123516] RAX: ffff8801366c63c0 RBX: 000000007bf81000 RCX: ffffffff813e4ee2 [ 140.126352] RDX: 0000000000000000 RSI: 0000000000007676 RDI: 000000007bf81000 [ 140.129236] RBP: ffffc90000dffdc0 R08: 0000000000000000 R09: 0000000000000000 [ 140.132110] R10: ffff880135895c80 R11: 0000000000000000 R12: 0000000000007676 [ 140.134955] R13: 0000000000008000 R14: 0000000000000000 R15: 0000000000007676 [ 140.137785] FS: 0000000000000000(0000) GS:ffff88013a680000(0063) knlGS:00000000f7db9700 [ 140.140998] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 [ 140.143303] CR2: 00000000f7ea56e0 CR3: 0000000134674004 CR4: 00000000000606e0 [ 140.145906] Call Trace: [ 140.146728] vm_brk_flags+0xc3/0x100 [ 140.147830] vm_brk+0x1f/0x30 [ 140.148714] load_elf_library+0x281/0x2e0 [ 140.149875] __ia32_sys_uselib+0x170/0x1e0 [ 140.151028] ? copy_overflow+0x30/0x30 [ 140.152105] ? __ia32_sys_uselib+0x170/0x1e0 [ 140.153301] do_fast_syscall_32+0xca/0x420 [ 140.154455] entry_SYSENTER_compat+0x70/0x7f The reason is that the length of the new brk is not page aligned when we try to populate the it. There is no reason to bug on that though. do_brk_flags already aligns the length properly so the mapping is expanded as it should. All we need is to tell mm_populate about it. Besides that there is absolutely no reason to to bug_on in the first place. The worst thing that could happen is that the last page wouldn't get populated and that is far from putting system into an inconsistent state. Fix the issue by moving the length sanitization code from do_brk_flags up to vm_brk_flags. The only other caller of do_brk_flags is brk syscall entry and it makes sure to provide the proper length so t here is no need for sanitation and so we can use do_brk_flags without it. Also remove the bogus BUG_ONs. [osalvador(a)techadventures.net: fix up vm_brk_flags s@request@len@] Link: http://lkml.kernel.org/r/20180706090217.GI32658@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko(a)suse.com> Reported-by: syzbot <syzbot+5dcb560fe12aa5091c06(a)syzkaller.appspotmail.com> Tested-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp> Reviewed-by: Oscar Salvador <osalvador(a)suse.de> Cc: Zi Yan <zi.yan(a)cs.rutgers.edu> Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)linux.vnet.ibm.com> Cc: Dan Williams <dan.j.williams(a)intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com> Cc: Michael S. Tsirkin <mst(a)redhat.com> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/gup.c | 2 -- mm/mmap.c | 29 ++++++++++++----------------- 2 files changed, 12 insertions(+), 19 deletions(-) diff -puN mm/gup.c~mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate mm/gup.c --- a/mm/gup.c~mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate +++ a/mm/gup.c @@ -1238,8 +1238,6 @@ int __mm_populate(unsigned long start, u int locked = 0; long ret = 0; - VM_BUG_ON(start & ~PAGE_MASK); - VM_BUG_ON(len != PAGE_ALIGN(len)); end = start + len; for (nstart = start; nstart < end; nstart = nend) { diff -puN mm/mmap.c~mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate mm/mmap.c --- a/mm/mmap.c~mm-do-not-bug_on-on-incorrect-lenght-in-__mm_populate +++ a/mm/mmap.c @@ -186,8 +186,8 @@ static struct vm_area_struct *remove_vma return next; } -static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf); - +static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags, + struct list_head *uf); SYSCALL_DEFINE1(brk, unsigned long, brk) { unsigned long retval; @@ -245,7 +245,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) goto out; /* Ok, looks good - let it rip. */ - if (do_brk(oldbrk, newbrk-oldbrk, &uf) < 0) + if (do_brk_flags(oldbrk, newbrk-oldbrk, 0, &uf) < 0) goto out; set_brk: @@ -2929,21 +2929,14 @@ static inline void verify_mm_writelocked * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ -static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long flags, struct list_head *uf) +static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long flags, struct list_head *uf) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; - unsigned long len; struct rb_node **rb_link, *rb_parent; pgoff_t pgoff = addr >> PAGE_SHIFT; int error; - len = PAGE_ALIGN(request); - if (len < request) - return -ENOMEM; - if (!len) - return 0; - /* Until we need other flags, refuse anything except VM_EXEC. */ if ((flags & (~VM_EXEC)) != 0) return -EINVAL; @@ -3015,18 +3008,20 @@ out: return 0; } -static int do_brk(unsigned long addr, unsigned long len, struct list_head *uf) -{ - return do_brk_flags(addr, len, 0, uf); -} - -int vm_brk_flags(unsigned long addr, unsigned long len, unsigned long flags) +int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags) { struct mm_struct *mm = current->mm; + unsigned long len; int ret; bool populate; LIST_HEAD(uf); + len = PAGE_ALIGN(request); + if (len < request) + return -ENOMEM; + if (!len) + return 0; + if (down_write_killable(&mm->mmap_sem)) return -EINTR; _ Patches currently in -mm which might be from mhocko(a)suse.com are mm-drop-vm_bug_on-from-__get_free_pages.patch memcg-oom-move-out_of_memory-back-to-the-charge-path.patch mm-oom-remove-sleep-from-under-oom_lock.patch mm-oom-document-oom_lock.patch mm-oom-docs-describe-the-cgroup-aware-oom-killer-fix-2.patch

6 years, 7 months

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[merged] fs-elf-make-sure-to-page-align-bss-in-load_elf_library.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: fs, elf: make sure to page align bss in load_elf_library has been removed from the -mm tree. Its filename was fs-elf-make-sure-to-page-align-bss-in-load_elf_library.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Oscar Salvador <osalvador(a)suse.de> Subject: fs, elf: make sure to page align bss in load_elf_library The current code does not make sure to page align bss before calling vm_brk(), and this can lead to a VM_BUG_ON() in __mm_populate() due to the requested lenght not being correctly aligned. Let us make sure to align it properly. Kees: only applicable to CONFIG_USELIB kernels: 32-bit and configured for libc5. Link: http://lkml.kernel.org/r/20180705145539.9627-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador(a)suse.de> Reported-by: syzbot+5dcb560fe12aa5091c06(a)syzkaller.appspotmail.com Tested-by: Tetsuo Handa <penguin-kernel(a)i-love.sakura.ne.jp> Acked-by: Kees Cook <keescook(a)chromium.org> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Nicolas Pitre <nicolas.pitre(a)linaro.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/binfmt_elf.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff -puN fs/binfmt_elf.c~fs-elf-make-sure-to-page-align-bss-in-load_elf_library fs/binfmt_elf.c --- a/fs/binfmt_elf.c~fs-elf-make-sure-to-page-align-bss-in-load_elf_library +++ a/fs/binfmt_elf.c @@ -1259,9 +1259,8 @@ static int load_elf_library(struct file goto out_free_ph; } - len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + - ELF_MIN_ALIGN - 1); - bss = eppnt->p_memsz + eppnt->p_vaddr; + len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); + bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); if (bss > len) { error = vm_brk(len, bss - len); if (error) _ Patches currently in -mm which might be from osalvador(a)suse.de are mm-memory_hotplug-make-add_memory_resource-use-__try_online_node.patch mm-memory_hotplug-call-register_mem_sect_under_node.patch mm-memory_hotplug-make-register_mem_sect_under_node-a-cb-of-walk_memory_range.patch mm-memory_hotplug-drop-unnecessary-checks-from-register_mem_sect_under_node.patch mm-sparse-make-sparse_init_one_section-void-and-remove-check.patch

6 years, 7 months

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[merged] x86-purgatory-add-missing-force-to-makefile-target.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: x86/purgatory: add missing FORCE to Makefile target has been removed from the -mm tree. Its filename was x86-purgatory-add-missing-force-to-makefile-target.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Philipp Rudo <prudo(a)linux.ibm.com> Subject: x86/purgatory: add missing FORCE to Makefile target - Build the kernel without the fix - Add some flag to the purgatories KBUILD_CFLAGS,I used -fno-asynchronous-unwind-tables - Re-build the kernel When you look at makes output you see that sha256.o is not re-build in the last step. Also readelf -S still shows the .eh_frame section for sha256.o. With the fix sha256.o is rebuilt in the last step. Without FORCE make does not detect changes only made to the command line options. So object files might not be re-built even when they should be. Fix this by adding FORCE where it is missing. Link: http://lkml.kernel.org/r/20180704110044.29279-2-prudo@linux.ibm.com Fixes: df6f2801f511 ("kernel/kexec_file.c: move purgatories sha256 to common code") Signed-off-by: Philipp Rudo <prudo(a)linux.ibm.com> Acked-by: Dave Young <dyoung(a)redhat.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: <stable(a)vger.kernel.org> [4.17+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/purgatory/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN arch/x86/purgatory/Makefile~x86-purgatory-add-missing-force-to-makefile-target arch/x86/purgatory/Makefile --- a/arch/x86/purgatory/Makefile~x86-purgatory-add-missing-force-to-makefile-target +++ a/arch/x86/purgatory/Makefile @@ -6,7 +6,7 @@ purgatory-y := purgatory.o stack.o setup targets += $(purgatory-y) PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y)) -$(obj)/sha256.o: $(srctree)/lib/sha256.c +$(obj)/sha256.o: $(srctree)/lib/sha256.c FORCE $(call if_changed_rule,cc_o_c) LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostdlib -z nodefaultlib _ Patches currently in -mm which might be from prudo(a)linux.ibm.com are

6 years, 7 months

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[merged] mm-fix-locked-field-in-proc-pid-smaps.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps* has been removed from the -mm tree. Its filename was mm-fix-locked-field-in-proc-pid-smaps.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Vlastimil Babka <vbabka(a)suse.cz> Subject: fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps* Thomas reports: : While looking around in /proc on my v4.14.52 system I noticed that : all processes got a lot of "Locked" memory in /proc/*/smaps. A lot : more memory than a regular user can usually lock with mlock(). : : commit 493b0e9d945fa9dfe96be93ae41b4ca4b6fdb317 (v4.14-rc1) seems : to have changed the behavior of "Locked". : : Before that commit the code was like this. Notice the VM_LOCKED : check. : : (vma->vm_flags & VM_LOCKED) ? : (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); : : After that commit Locked is now the same as Pss. This looks like a : mistake. : : (unsigned long)(mss->pss >> (10 + PSS_SHIFT))); Indeed, the commit has added mss->pss_locked with the correct value that depends on VM_LOCKED, but forgot to actually use it. Fix it. Link: http://lkml.kernel.org/r/ebf6c7fb-fec3-6a26-544f-710ed193c154@suse.cz Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka <vbabka(a)suse.cz> Reported-by: Thomas Lindroth <thomas.lindroth(a)gmail.com> Cc: Alexey Dobriyan <adobriyan(a)gmail.com> Cc: Daniel Colascione <dancol(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/proc/task_mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff -puN fs/proc/task_mmu.c~mm-fix-locked-field-in-proc-pid-smaps fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~mm-fix-locked-field-in-proc-pid-smaps +++ a/fs/proc/task_mmu.c @@ -831,7 +831,8 @@ static int show_smap(struct seq_file *m, SEQ_PUT_DEC(" kB\nSwap: ", mss->swap); SEQ_PUT_DEC(" kB\nSwapPss: ", mss->swap_pss >> PSS_SHIFT); - SEQ_PUT_DEC(" kB\nLocked: ", mss->pss >> PSS_SHIFT); + SEQ_PUT_DEC(" kB\nLocked: ", + mss->pss_locked >> PSS_SHIFT); seq_puts(m, " kB\n"); } if (!rollup_mode) { _ Patches currently in -mm which might be from vbabka(a)suse.cz are mm-page_alloc-actually-ignore-mempolicies-for-high-priority-allocations.patch

6 years, 7 months

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[merged] mm-do-not-drop-unused-pages-when-userfaultd-is-running.patch removed from -mm tree

by akpm＠linux-foundation.org

The patch titled Subject: mm: do not drop unused pages when userfaultd is running has been removed from the -mm tree. Its filename was mm-do-not-drop-unused-pages-when-userfaultd-is-running.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Christian Borntraeger <borntraeger(a)de.ibm.com> Subject: mm: do not drop unused pages when userfaultd is running KVM guests on s390 can notify the host of unused pages. This can result in pte_unused callbacks to be true for KVM guest memory. If a page is unused (checked with pte_unused) we might drop this page instead of paging it. This can have side-effects on userfaultd, when the page in question was already migrated: The next access of that page will trigger a fault and a user fault instead of faulting in a new and empty zero page. As QEMU does not expect a userfault on an already migrated page this migration will fail. The most straightforward solution is to ignore the pte_unused hint if a userfault context is active for this VMA. Link: http://lkml.kernel.org/r/20180703171854.63981-1-borntraeger@de.ibm.com Signed-off-by: Christian Borntraeger <borntraeger(a)de.ibm.com> Cc: Martin Schwidefsky <schwidefsky(a)de.ibm.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: Mike Rapoport <rppt(a)linux.vnet.ibm.com> Cc: Janosch Frank <frankja(a)linux.ibm.com> Cc: David Hildenbrand <david(a)redhat.com> Cc: Cornelia Huck <cohuck(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/rmap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff -puN mm/rmap.c~mm-do-not-drop-unused-pages-when-userfaultd-is-running mm/rmap.c --- a/mm/rmap.c~mm-do-not-drop-unused-pages-when-userfaultd-is-running +++ a/mm/rmap.c @@ -64,6 +64,7 @@ #include <linux/backing-dev.h> #include <linux/page_idle.h> #include <linux/memremap.h> +#include <linux/userfaultfd_k.h> #include <asm/tlbflush.h> @@ -1481,11 +1482,16 @@ static bool try_to_unmap_one(struct page set_pte_at(mm, address, pvmw.pte, pteval); } - } else if (pte_unused(pteval)) { + } else if (pte_unused(pteval) && !userfaultfd_armed(vma)) { /* * The guest indicated that the page content is of no * interest anymore. Simply discard the pte, vmscan * will take care of the rest. + * A future reference will then fault in a new zero + * page. When userfaultfd is active, we must not drop + * this page though, as its main user (postcopy + * migration) will not expect userfaults on already + * copied pages. */ dec_mm_counter(mm, mm_counter(page)); /* We have to invalidate as we cleared the pte */ _ Patches currently in -mm which might be from borntraeger(a)de.ibm.com are

6 years, 7 months

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[PATCH] perf kvm: Fix subcommands on s390

by Thomas Richter

With commit eca0fa28cd0d ("perf record: Provide detailed information on s390 CPU") s390 platform provides detailed type/model/capacitiy information in the CPU indentifier string instead of just "IBM/S390". This breaks perf kvm support which uses hard coded string IBM/S390 to compare with the CPU identifier string. Fix this by changing the comparison. Fixes: eca0fa28cd0d ("perf record: Provide detailed information on s390 CPU") Cc: Stefan Raspl <raspl(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> # 4.17 Signed-off-by: Thomas Richter <tmricht(a)linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner(a)linux.ibm.com> --- tools/perf/arch/s390/util/kvm-stat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/arch/s390/util/kvm-stat.c b/tools/perf/arch/s390/util/kvm-stat.c index d233e2eb9592..aaabab5e2830 100644 --- a/tools/perf/arch/s390/util/kvm-stat.c +++ b/tools/perf/arch/s390/util/kvm-stat.c @@ -102,7 +102,7 @@ const char * const kvm_skip_events[] = { int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid) { - if (strstr(cpuid, "IBM/S390")) { + if (strstr(cpuid, "IBM")) { kvm->exit_reasons = sie_exit_reasons; kvm->exit_reasons_isa = "SIE"; } else -- 2.14.3

6 years, 7 months

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[PATCH 4.4.y 051/101] x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen

by Srivatsa S. Bhat

From: David Woodhouse <dwmw(a)amazon.co.uk> commit def9331a12977770cc6132d79f8e6565871e8e38 upstream When running as Xen pv guest X86_BUG_SYSRET_SS_ATTRS must not be set on AMD cpus. This bug/feature bit is kind of special as it will be used very early when switching threads. Setting the bit and clearing it a little bit later leaves a critical window where things can go wrong. This time window has enlarged a little bit by using setup_clear_cpu_cap() instead of the hypervisor's set_cpu_features callback. It seems this larger window now makes it rather easy to hit the problem. The proper solution is to never set the bit in case of Xen. Signed-off-by: Juergen Gross <jgross(a)suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Acked-by: Thomas Gleixner <tglx(a)linutronix.de> Signed-off-by: Juergen Gross <jgross(a)suse.com> Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Srivatsa S. Bhat <srivatsa(a)csail.mit.edu> Reviewed-by: Matt Helsley (VMware) <matt.helsley(a)gmail.com> Reviewed-by: Alexey Makhalov <amakhalov(a)vmware.com> Reviewed-by: Bo Gan <ganb(a)vmware.com> --- arch/x86/kernel/cpu/amd.c | 5 +++-- arch/x86/xen/enlighten.c | 4 +--- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index f4fb8f5..9b29414 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -791,8 +791,9 @@ static void init_amd(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM)) set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH); - /* AMD CPUs don't reset SS attributes on SYSRET */ - set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); + /* AMD CPUs don't reset SS attributes on SYSRET, Xen does. */ + if (!cpu_has(c, X86_FEATURE_XENPV)) + set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); } #ifdef CONFIG_X86_32 diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 2d7ab4e..82fd84d 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -462,10 +462,8 @@ static void __init xen_init_cpuid_mask(void) static void __init xen_init_capabilities(void) { - if (xen_pv_domain()) { - setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS); + if (xen_pv_domain()) setup_force_cpu_cap(X86_FEATURE_XENPV); - } } static void xen_set_debugreg(int reg, unsigned long val)

6 years, 7 months

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Re: [PATCH 4.17 62/67] kvm: vmx: Nested VM-entry prereqs for event inj.

by Marc Orr

On Mon, Jul 16, 2018 at 12:39 AM Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> wrote: > > 4.17-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Marc Orr <marcorr(a)google.com> > > commit 0447378a4a793da008451fad50bc0f93e9675ae6 upstream. > > This patch extends the checks done prior to a nested VM entry. > Specifically, it extends the check_vmentry_prereqs function with checks > for fields relevant to the VM-entry event injection information, as > described in the Intel SDM, volume 3. > > This patch is motivated by a syzkaller bug, where a bad VM-entry > interruption information field is generated in the VMCS02, which causes > the nested VM launch to fail. Then, KVM fails to resume L1. > > While KVM should be improved to correctly resume L1 execution after a > failed nested launch, this change is justified because the existing code > to resume L1 is flaky/ad-hoc and the test coverage for resuming L1 is > sparse. > > Reported-by: syzbot <syzkaller(a)googlegroups.com> > Signed-off-by: Marc Orr <marcorr(a)google.com> > [Removed comment whose parts were describing previous revisions and the > rest was obvious from function/variable naming. - Radim] > Signed-off-by: Radim Krčmář <rkrcmar(a)redhat.com> > Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> > > --- > arch/x86/include/asm/vmx.h | 3 ++ > arch/x86/kvm/vmx.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ > arch/x86/kvm/x86.h | 9 ++++++ > 3 files changed, 79 insertions(+) > > --- a/arch/x86/include/asm/vmx.h > +++ b/arch/x86/include/asm/vmx.h > @@ -114,6 +114,7 @@ > #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f > #define VMX_MISC_SAVE_EFER_LMA 0x00000020 > #define VMX_MISC_ACTIVITY_HLT 0x00000040 > +#define VMX_MISC_ZERO_LEN_INS 0x40000000 > > /* VMFUNC functions */ > #define VMX_VMFUNC_EPTP_SWITCHING 0x00000001 > @@ -349,11 +350,13 @@ enum vmcs_field { > #define VECTORING_INFO_VALID_MASK INTR_INFO_VALID_MASK > > #define INTR_TYPE_EXT_INTR (0 << 8) /* external interrupt */ > +#define INTR_TYPE_RESERVED (1 << 8) /* reserved */ > #define INTR_TYPE_NMI_INTR (2 << 8) /* NMI */ > #define INTR_TYPE_HARD_EXCEPTION (3 << 8) /* processor exception */ > #define INTR_TYPE_SOFT_INTR (4 << 8) /* software interrupt */ > #define INTR_TYPE_PRIV_SW_EXCEPTION (5 << 8) /* ICE breakpoint - undocumented */ > #define INTR_TYPE_SOFT_EXCEPTION (6 << 8) /* software exception */ > +#define INTR_TYPE_OTHER_EVENT (7 << 8) /* other event */ > > /* GUEST_INTERRUPTIBILITY_INFO flags. */ > #define GUEST_INTR_STATE_STI 0x00000001 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -1510,6 +1510,17 @@ static inline unsigned nested_cpu_vmx_mi > return vmx_misc_cr3_count(to_vmx(vcpu)->nested.msrs.misc_low); > } > > +static inline bool nested_cpu_has_zero_length_injection(struct kvm_vcpu *vcpu) > +{ > + return to_vmx(vcpu)->nested.msrs.misc_low & VMX_MISC_ZERO_LEN_INS; > +} > + > +static inline bool nested_cpu_supports_monitor_trap_flag(struct kvm_vcpu *vcpu) > +{ > + return to_vmx(vcpu)->nested.msrs.procbased_ctls_high & > + CPU_BASED_MONITOR_TRAP_FLAG; > +} > + > static inline bool nested_cpu_has(struct vmcs12 *vmcs12, u32 bit) > { > return vmcs12->cpu_based_vm_exec_control & bit; > @@ -11364,6 +11375,62 @@ static int check_vmentry_prereqs(struct > !nested_cr3_valid(vcpu, vmcs12->host_cr3)) > return VMXERR_ENTRY_INVALID_HOST_STATE_FIELD; > > + /* > + * From the Intel SDM, volume 3: > + * Fields relevant to VM-entry event injection must be set properly. > + * These fields are the VM-entry interruption-information field, the > + * VM-entry exception error code, and the VM-entry instruction length. > + */ > + if (vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK) { > + u32 intr_info = vmcs12->vm_entry_intr_info_field; > + u8 vector = intr_info & INTR_INFO_VECTOR_MASK; > + u32 intr_type = intr_info & INTR_INFO_INTR_TYPE_MASK; > + bool has_error_code = intr_info & INTR_INFO_DELIVER_CODE_MASK; > + bool should_have_error_code; > + bool urg = nested_cpu_has2(vmcs12, > + SECONDARY_EXEC_UNRESTRICTED_GUEST); > + bool prot_mode = !urg || vmcs12->guest_cr0 & X86_CR0_PE; > + > + /* VM-entry interruption-info field: interruption type */ > + if (intr_type == INTR_TYPE_RESERVED || > + (intr_type == INTR_TYPE_OTHER_EVENT && > + !nested_cpu_supports_monitor_trap_flag(vcpu))) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + > + /* VM-entry interruption-info field: vector */ > + if ((intr_type == INTR_TYPE_NMI_INTR && vector != NMI_VECTOR) || > + (intr_type == INTR_TYPE_HARD_EXCEPTION && vector > 31) || > + (intr_type == INTR_TYPE_OTHER_EVENT && vector != 0)) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + > + /* VM-entry interruption-info field: deliver error code */ > + should_have_error_code = > + intr_type == INTR_TYPE_HARD_EXCEPTION && prot_mode && > + x86_exception_has_error_code(vector); > + if (has_error_code != should_have_error_code) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + > + /* VM-entry exception error code */ > + if (has_error_code && > + vmcs12->vm_entry_exception_error_code & GENMASK(31, 15)) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + > + /* VM-entry interruption-info field: reserved bits */ > + if (intr_info & INTR_INFO_RESVD_BITS_MASK) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + > + /* VM-entry instruction length */ > + switch (intr_type) { > + case INTR_TYPE_SOFT_EXCEPTION: > + case INTR_TYPE_SOFT_INTR: > + case INTR_TYPE_PRIV_SW_EXCEPTION: > + if ((vmcs12->vm_entry_instruction_len > 15) || > + (vmcs12->vm_entry_instruction_len == 0 && > + !nested_cpu_has_zero_length_injection(vcpu))) > + return VMXERR_ENTRY_INVALID_CONTROL_FIELD; > + } > + } > + > return 0; > } > > --- a/arch/x86/kvm/x86.h > +++ b/arch/x86/kvm/x86.h > @@ -110,6 +110,15 @@ static inline bool is_la57_mode(struct k > #endif > } > > +static inline bool x86_exception_has_error_code(unsigned int vector) > +{ > + static u32 exception_has_error_code = BIT(DF_VECTOR) | BIT(TS_VECTOR) | > + BIT(NP_VECTOR) | BIT(SS_VECTOR) | BIT(GP_VECTOR) | > + BIT(PF_VECTOR) | BIT(AC_VECTOR); > + > + return (1U << vector) & exception_has_error_code; > +} > + > static inline bool mmu_is_nested(struct kvm_vcpu *vcpu) > { > return vcpu->arch.walk_mmu == &vcpu->arch.nested_mmu; > > Reviewed-by: Marc Orr <marcorr(a)google.com>

6 years, 7 months

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[PATCH] kernel.h: Avoid that sparse complains about using sizeof(void)

by Bart Van Assche

The macro __is_constexpr() causes sparse to report the following: warning: expression using sizeof(void) Avoid this by using __builtin_constant_p() instead. Fixes: 3c8ba0d61d04 ("kernel.h: Retain constant expression output for max()/min()") Signed-off-by: Bart Van Assche <bart.vanassche(a)wdc.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Martin Uecker <Martin.Uecker(a)med.uni-goettingen.de> Cc: Kees Cook <keescook(a)chromium.org> Cc: Ingo Molnar <mingo(a)kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com> Cc: <stable(a)vger.kernel.org> --- include/linux/kernel.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d23123238534..a9f0d0d48971 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -811,13 +811,19 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #define __typecheck(x, y) \ (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) +#ifndef __CHECKER__ /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. - * Glory to Martin Uecker <Martin.Uecker(a)med.uni-goettingen.de> + * Glory to Martin Uecker <Martin.Uecker(a)med.uni-goettingen.de>. However, this + * macro causes sparse to report the warning "expression using sizeof(void)". + * Hence use __builtin_constant_p() instead when using sparse. */ #define __is_constexpr(x) \ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) +#else +#define __is_constexpr(x) __builtin_constant_p((x)) +#endif #define __no_side_effects(x, y) \ (__is_constexpr(x) && __is_constexpr(y)) -- 2.18.0

6 years, 7 months

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Linux-stable-mirror July 2018