user/sven/linux.git/arch, branch v3.14.36

ARC: Fix KSTK_ESP()

2015-03-18T12:31:31Z

commit 13648b0118a24f4fc76c34e6c7b6ccf447e46a2a upstream. /proc//maps currently don't annotate stack vma with "[stack]" This is because KSTK_ESP ie expected to return usermode SP of tsk while currently it returns the kernel mode SP of a sleeping tsk. While the fix is trivial, we also need to adjust the ARC kernel stack unwinder to not use KSTK_SP and friends any more. Reported-and-suggested-by: Alexey Brodkin Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman

KVM: MIPS: Fix trace event to save PC directly

2015-03-18T12:31:28Z

commit b3cffac04eca9af46e1e23560a8ee22b1bd36d43 upstream. Currently the guest exit trace event saves the VCPU pointer to the structure, and the guest PC is retrieved by dereferencing it when the event is printed rather than directly from the trace record. This isn't safe as the printing may occur long afterwards, after the PC has changed and potentially after the VCPU has been freed. Usually this results in the same (wrong) PC being printed for multiple trace events. It also isn't portable as userland has no way to access the VCPU data structure when interpreting the trace record itself. Lets save the actual PC in the structure so that the correct value is accessible later. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Ralf Baechle Cc: Marcelo Tosatti Cc: Gleb Natapov Cc: Steven Rostedt Cc: Ingo Molnar Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Acked-by: Steven Rostedt Signed-off-by: Marcelo Tosatti Signed-off-by: Greg Kroah-Hartman

KVM: emulate: fix CMPXCHG8B on 32-bit hosts

2015-03-18T12:31:28Z

commit 4ff6f8e61eb7f96d3ca535c6d240f863ccd6fb7d upstream. This has been broken for a long time: it broke first in 2.6.35, then was almost fixed in 2.6.36 but this one-liner slipped through the cracks. The bug shows up as an infinite loop in Windows 7 (and newer) boot on 32-bit hosts without EPT. Windows uses CMPXCHG8B to write to page tables, which causes a page fault if running without EPT; the emulator is then called from kvm_mmu_page_fault. The loop then happens if the higher 4 bytes are not 0; the common case for this is that the NX bit (bit 63) is 1. Fixes: 6550e1f165f384f3a46b60a1be9aba4bc3c2adad Fixes: 16518d5ada690643453eb0aef3cc7841d3623c2d Reported-by: Erik Rull Tested-by: Erik Rull Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization

2015-03-18T12:31:25Z

commit 956421fbb74c3a6261903f3836c0740187cf038b upstream. 'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and the related state make sense for 'ret_from_sys_call'. This is entirely the wrong check. TS_COMPAT would make a little more sense, but there's really no point in keeping this optimization at all. This fixes a return to the wrong user CS if we came from int 0x80 in a 64-bit task. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.net [ Backported from tip:x86/asm. ] Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86, mm/ASLR: Fix stack randomization on 64-bit systems

2015-03-06T22:43:32Z

commit 4e7c22d447bb6d7e37bfe39ff658486ae78e8d77 upstream. The issue is that the stack for processes is not properly randomized on 64 bit architectures due to an integer overflow. The affected function is randomize_stack_top() in file "fs/binfmt_elf.c": static unsigned long randomize_stack_top(unsigned long stack_top) { unsigned int random_variable = 0; if ((current->flags & PF_RANDOMIZE) && !(current->personality & ADDR_NO_RANDOMIZE)) { random_variable = get_random_int() & STACK_RND_MASK; random_variable <<= PAGE_SHIFT; } return PAGE_ALIGN(stack_top) + random_variable; return PAGE_ALIGN(stack_top) - random_variable; } Note that, it declares the "random_variable" variable as "unsigned int". Since the result of the shifting operation between STACK_RND_MASK (which is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64): random_variable <<= PAGE_SHIFT; then the two leftmost bits are dropped when storing the result in the "random_variable". This variable shall be at least 34 bits long to hold the (22+12) result. These two dropped bits have an impact on the entropy of process stack. Concretely, the total stack entropy is reduced by four: from 2^28 to 2^30 (One fourth of expected entropy). This patch restores back the entropy by correcting the types involved in the operations in the functions randomize_stack_top() and stack_maxrandom_size(). The successful fix can be tested with: $ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done 7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0 [stack] 7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0 [stack] 7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0 [stack] 7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0 [stack] ... Once corrected, the leading bytes should be between 7ffc and 7fff, rather than always being 7fff. Signed-off-by: Hector Marco-Gisbert Signed-off-by: Ismael Ripoll [ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ] Signed-off-by: Kees Cook Cc: Linus Torvalds Cc: Andrew Morton Cc: Al Viro Fixes: CVE-2015-1593 Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net Signed-off-by: Borislav Petkov Signed-off-by: Greg Kroah-Hartman

metag: Fix KSTK_EIP() and KSTK_ESP() macros

2015-03-06T22:43:31Z

commit c2996cb29bfb73927a79dc96e598a718e843f01a upstream. The KSTK_EIP() and KSTK_ESP() macros should return the user program counter (PC) and stack pointer (A0StP) of the given task. These are used to determine which VMA corresponds to the user stack in /proc//maps, and for the user PC & A0StP in /proc//stat. However for Meta the PC & A0StP from the task's kernel context are used, resulting in broken output. For example in following /proc//maps output, the 3afff000-3b021000 VMA should be described as the stack: # cat /proc/self/maps ... 100b0000-100b1000 rwxp 00000000 00:00 0 [heap] 3afff000-3b021000 rwxp 00000000 00:00 0 And in the following /proc//stat output, the PC is in kernel code (1074234964 = 0x40078654) and the A0StP is in the kernel heap (1335981392 = 0x4fa17550): # cat /proc/self/stat 51 (cat) R ... 1335981392 1074234964 ... Fix the definitions of KSTK_EIP() and KSTK_ESP() to use task_pt_regs(tsk)->ctx rather than (tsk)->thread.kernel_context. This gets the registers from the user context stored after the thread info at the base of the kernel stack, which is from the last entry into the kernel from userland, regardless of where in the kernel the task may have been interrupted, which results in the following more correct /proc//maps output: # cat /proc/self/maps ... 0800b000-08070000 r-xp 00000000 00:02 207 /lib/libuClibc-0.9.34-git.so ... 100b0000-100b1000 rwxp 00000000 00:00 0 [heap] 3afff000-3b021000 rwxp 00000000 00:00 0 [stack] And /proc//stat now correctly reports the PC in libuClibc (134320308 = 0x80190b4) and the A0StP in the [stack] region (989864576 = 0x3b002280): # cat /proc/self/stat 51 (cat) R ... 989864576 134320308 ... Reported-by: Alexey Brodkin Reported-by: Vineet Gupta Signed-off-by: James Hogan Cc: linux-metag@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

arm64: compat Fix siginfo_t -> compat_siginfo_t conversion on big endian

2015-03-06T22:43:31Z

commit 9d42d48a342aee208c1154696196497fdc556bbf upstream. The native (64-bit) sigval_t union contains sival_int (32-bit) and sival_ptr (64-bit). When a compat application invokes a syscall that takes a sigval_t value (as part of a larger structure, e.g. compat_sys_mq_notify, compat_sys_timer_create), the compat_sigval_t union is converted to the native sigval_t with sival_int overlapping with either the least or the most significant half of sival_ptr, depending on endianness. When the corresponding signal is delivered to a compat application, on big endian the current (compat_uptr_t)sival_ptr cast always returns 0 since sival_int corresponds to the top part of sival_ptr. This patch fixes copy_siginfo_to_user32() so that sival_int is copied to the compat_siginfo_t structure. Reported-by: Bamvor Jian Zhang Tested-by: Bamvor Jian Zhang Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman

hx4700: regulator: declare full constraints

2015-03-06T22:43:31Z

commit a52d209336f8fc7483a8c7f4a8a7d2a8e1692a6c upstream. Since the removal of CONFIG_REGULATOR_DUMMY option, the touchscreen stopped working. This patch enables the "replacement" for REGULATOR_DUMMY and allows the touchscreen to work even though there is no regulator for "vcc". Signed-off-by: Martin Vajnar Signed-off-by: Robert Jarzmik Signed-off-by: Greg Kroah-Hartman

KVM: x86: update masterclock values on TSC writes

2015-03-06T22:43:31Z

commit 7f187922ddf6b67f2999a76dcb71663097b75497 upstream. When the guest writes to the TSC, the masterclock TSC copy must be updated as well along with the TSC_OFFSET update, otherwise a negative tsc_timestamp is calculated at kvm_guest_time_update. Once "if (!vcpus_matched && ka->use_master_clock)" is simplified to "if (ka->use_master_clock)", the corresponding "if (!ka->use_master_clock)" becomes redundant, so remove the do_request boolean and collapse everything into a single condition. Signed-off-by: Marcelo Tosatti Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

KVM: MIPS: Don't leak FPU/DSP to guest

2015-03-06T22:43:31Z

commit f798217dfd038af981a18bbe4bc57027a08bb182 upstream. The FPU and DSP are enabled via the CP0 Status CU1 and MX bits by kvm_mips_set_c0_status() on a guest exit, presumably in case there is active state that needs saving if pre-emption occurs. However neither of these bits are cleared again when returning to the guest. This effectively gives the guest access to the FPU/DSP hardware after the first guest exit even though it is not aware of its presence, allowing FP instructions in guest user code to intermittently actually execute instead of trapping into the guest OS for emulation. It will then read & manipulate the hardware FP registers which technically belong to the user process (e.g. QEMU), or are stale from another user process. It can also crash the guest OS by causing an FP exception, for which a guest exception handler won't have been registered. First lets save and disable the FPU (and MSA) state with lose_fpu(1) before entering the guest. This simplifies the problem, especially for when guest FPU/MSA support is added in the future, and prevents FR=1 FPU state being live when the FR bit gets cleared for the guest, which according to the architecture causes the contents of the FPU and vector registers to become UNPREDICTABLE. We can then safely remove the enabling of the FPU in kvm_mips_set_c0_status(), since there should never be any active FPU or MSA state to save at pre-emption, which should plug the FPU leak. DSP state is always live rather than being lazily restored, so for that it is simpler to just clear the MX bit again when re-entering the guest. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Ralf Baechle Cc: Sanjay Lal Cc: Gleb Natapov Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: # v3.10+: 044f0f03eca0: MIPS: KVM: Deliver guest interrupts Cc: # v3.10+ Signed-off-by: Paolo Bonzini Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman