linux-stable.git/arch, branch v3.2.76 Linux kernel stable tree kvm: x86: only channel 0 of the i8254 is linked to the HPET 2016-01-22T21:40:09+00:00 Paolo Bonzini pbonzini@redhat.com 2016-01-07T12:50:38+00:00 ef90cf3d0b59e3b1dcfe94d1a241107667e6e96a commit e5e57e7a03b1cdcb98e4aed135def2a08cbf3257 upstream. While setting the KVM PIT counters in 'kvm_pit_load_count', if 'hpet_legacy_start' is set, the function disables the timer on channel[0], instead of the respective index 'channel'. This is because channels 1-3 are not linked to the HPET. Fix the caller to only activate the special HPET processing for channel 0. Reported-by: P J P <pjp@fedoraproject.org> Fixes: 0185604c2d82c560dab2f2933a18f797e74ab5a8 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e5e57e7a03b1cdcb98e4aed135def2a08cbf3257 upstream.

While setting the KVM PIT counters in 'kvm_pit_load_count', if
'hpet_legacy_start' is set, the function disables the timer on
channel[0], instead of the respective index 'channel'. This is
because channels 1-3 are not linked to the HPET.  Fix the caller
to only activate the special HPET processing for channel 0.

Reported-by: P J P <pjp@fedoraproject.org>
Fixes: 0185604c2d82c560dab2f2933a18f797e74ab5a8
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
KVM: x86: Reload pit counters for all channels when restoring state 2016-01-22T21:40:09+00:00 Andrew Honig ahonig@google.com 2015-11-18T22:50:23+00:00 08b8d1a6ccdefd3d517d04c472b7f42f51b3059b commit 0185604c2d82c560dab2f2933a18f797e74ab5a8 upstream. Currently if userspace restores the pit counters with a count of 0 on channels 1 or 2 and the guest attempts to read the count on those channels, then KVM will perform a mod of 0 and crash. This will ensure that 0 values are converted to 65536 as per the spec. This is CVE-2015-7513. Signed-off-by: Andy Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 0185604c2d82c560dab2f2933a18f797e74ab5a8 upstream.

Currently if userspace restores the pit counters with a count of 0
on channels 1 or 2 and the guest attempts to read the count on those
channels, then KVM will perform a mod of 0 and crash.  This will ensure
that 0 values are converted to 65536 as per the spec.

This is CVE-2015-7513.

Signed-off-by: Andy Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
MIPS: Fix restart of indirect syscalls 2016-01-22T21:40:08+00:00 Ed Swierk eswierk@skyportsystems.com 2015-01-13T05:10:30+00:00 08f865bba9c705aef95268a33393698e5385587e commit e967ef022e00bb7c2e5b1a42007abfdd52055050 upstream. When 32-bit MIPS userspace invokes a syscall indirectly via syscall(number, arg1, ..., arg7), the kernel looks up the actual syscall based on the given number, shifts the other arguments to the left, and jumps to the syscall. If the syscall is interrupted by a signal and indicates it needs to be restarted by the kernel (by returning ERESTARTNOINTR for example), the syscall must be called directly, since the number is no longer the first argument, and the other arguments are now staged for a direct call. Before shifting the arguments, store the syscall number in pt_regs->regs[2]. This gets copied temporarily into pt_regs->regs[0] after the syscall returns. If the syscall needs to be restarted, handle_signal()/do_signal() copies the number back to pt_regs->reg[2], which ends up in $v0 once control returns to userspace. Signed-off-by: Ed Swierk <eswierk@skyportsystems.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8929/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit e967ef022e00bb7c2e5b1a42007abfdd52055050 upstream.

When 32-bit MIPS userspace invokes a syscall indirectly via syscall(number,
arg1, ..., arg7), the kernel looks up the actual syscall based on the given
number, shifts the other arguments to the left, and jumps to the syscall.

If the syscall is interrupted by a signal and indicates it needs to be
restarted by the kernel (by returning ERESTARTNOINTR for example), the
syscall must be called directly, since the number is no longer the first
argument, and the other arguments are now staged for a direct call.

Before shifting the arguments, store the syscall number in pt_regs->regs[2].
This gets copied temporarily into pt_regs->regs[0] after the syscall returns.
If the syscall needs to be restarted, handle_signal()/do_signal() copies the
number back to pt_regs->reg[2], which ends up in $v0 once control returns to
userspace.

Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8929/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
parisc: Fix syscall restarts 2016-01-22T21:40:08+00:00 Helge Deller deller@gmx.de 2015-12-21T09:03:30+00:00 9f2dcffefc599c424ad1dd402e3a96da60639308 commit 71a71fb5374a23be36a91981b5614590b9e722c3 upstream. On parisc syscalls which are interrupted by signals sometimes failed to restart and instead returned -ENOSYS which in the worst case lead to userspace crashes. A similiar problem existed on MIPS and was fixed by commit e967ef02 ("MIPS: Fix restart of indirect syscalls"). On parisc the current syscall restart code assumes that all syscall callers load the syscall number in the delay slot of the ble instruction. That's how it is e.g. done in the unistd.h header file: ble 0x100(%sr2, %r0) ldi #syscall_nr, %r20 Because of that assumption the current code never restored %r20 before returning to userspace. This assumption is at least not true for code which uses the glibc syscall() function, which instead uses this syntax: ble 0x100(%sr2, %r0) copy regX, %r20 where regX depend on how the compiler optimizes the code and register usage. This patch fixes this problem by adding code to analyze how the syscall number is loaded in the delay branch and - if needed - copy the syscall number to regX prior returning to userspace for the syscall restart. Signed-off-by: Helge Deller <deller@gmx.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 71a71fb5374a23be36a91981b5614590b9e722c3 upstream.

On parisc syscalls which are interrupted by signals sometimes failed to
restart and instead returned -ENOSYS which in the worst case lead to
userspace crashes.
A similiar problem existed on MIPS and was fixed by commit e967ef02
("MIPS: Fix restart of indirect syscalls").

On parisc the current syscall restart code assumes that all syscall
callers load the syscall number in the delay slot of the ble
instruction. That's how it is e.g. done in the unistd.h header file:
	ble 0x100(%sr2, %r0)
	ldi #syscall_nr, %r20
Because of that assumption the current code never restored %r20 before
returning to userspace.

This assumption is at least not true for code which uses the glibc
syscall() function, which instead uses this syntax:
	ble 0x100(%sr2, %r0)
	copy regX, %r20
where regX depend on how the compiler optimizes the code and register
usage.

This patch fixes this problem by adding code to analyze how the syscall
number is loaded in the delay branch and - if needed - copy the syscall
number to regX prior returning to userspace for the syscall restart.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
s390/dis: Fix handling of format specifiers 2016-01-22T21:40:06+00:00 Michael Holzheu holzheu@linux.vnet.ibm.com 2015-12-17T18:06:02+00:00 45f32e359d36dd045e4af0d1bea8bbbafd81eeb7 commit 272fa59ccb4fc802af28b1d699c2463db6a71bf7 upstream. The print_insn() function returns strings like "lghi %r1,0". To escape the '%' character in sprintf() a second '%' is used. For example "lghi %%r1,0" is converted into "lghi %r1,0". After print_insn() the output string is passed to printk(). Because format specifiers like "%r" or "%f" are ignored by printk() this works by chance most of the time. But for instructions with control registers like "lctl %c6,%c6,780" this fails because printk() interprets "%c" as character format specifier. Fix this problem and escape the '%' characters twice. For example "lctl %%%%c6,%%%%c6,780" is then converted by sprintf() into "lctl %%c6,%%c6,780" and by printk() into "lctl %c6,%c6,780". Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: drop the OPERAND_VR case] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 272fa59ccb4fc802af28b1d699c2463db6a71bf7 upstream.

The print_insn() function returns strings like "lghi %r1,0". To escape the
'%' character in sprintf() a second '%' is used. For example "lghi %%r1,0"
is converted into "lghi %r1,0".

After print_insn() the output string is passed to printk(). Because format
specifiers like "%r" or "%f" are ignored by printk() this works by chance
most of the time. But for instructions with control registers like
"lctl %c6,%c6,780" this fails because printk() interprets "%c" as
character format specifier.

Fix this problem and escape the '%' characters twice.

For example "lctl %%%%c6,%%%%c6,780" is then converted by sprintf()
into "lctl %%c6,%%c6,780" and by printk() into "lctl %c6,%c6,780".

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[bwh: Backported to 3.2: drop the OPERAND_VR case]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sh64: fix __NR_fgetxattr 2015-12-30T02:26:01+00:00 Dmitry V. Levin ldv@altlinux.org 2015-12-11T21:41:06+00:00 3953ba754ad4e00a58fbc20a9498c999ffe82f61 commit 2d33fa1059da4c8e816627a688d950b613ec0474 upstream. According to arch/sh/kernel/syscalls_64.S and common sense, __NR_fgetxattr has to be defined to 259, but it doesn't. Instead, it's defined to 269, which is of course used by another syscall, __NR_sched_setaffinity in this case. This bug was found by strace test suite. Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 2d33fa1059da4c8e816627a688d950b613ec0474 upstream.

According to arch/sh/kernel/syscalls_64.S and common sense, __NR_fgetxattr
has to be defined to 259, but it doesn't.  Instead, it's defined to 269,
which is of course used by another syscall, __NR_sched_setaffinity in this
case.

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
KVM: svm: unconditionally intercept #DB 2015-11-27T12:48:24+00:00 Paolo Bonzini pbonzini@redhat.com 2015-11-10T08:14:39+00:00 b42506c6c820764f26e3036dfd733e0401525c88 commit cbdb967af3d54993f5814f1cee0ed311a055377d upstream. This is needed to avoid the possibility that the guest triggers an infinite stream of #DB exceptions (CVE-2015-8104). VMX is not affected: because it does not save DR6 in the VMCS, it already intercepts #DB unconditionally. Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2, with thanks to Paolo: - update_db_bp_intercept() was called update_db_intercept() - The remaining call is in svm_guest_debug() rather than through svm_x86_ops] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit cbdb967af3d54993f5814f1cee0ed311a055377d upstream.

This is needed to avoid the possibility that the guest triggers
an infinite stream of #DB exceptions (CVE-2015-8104).

VMX is not affected: because it does not save DR6 in the VMCS,
it already intercepts #DB unconditionally.

Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2, with thanks to Paolo:
 - update_db_bp_intercept() was called update_db_intercept()
 - The remaining call is in svm_guest_debug() rather than through svm_x86_ops]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
x86/cpu: Call verify_cpu() after having entered long mode too 2015-11-27T12:48:23+00:00 Borislav Petkov bp@suse.de 2015-11-05T15:57:56+00:00 7f28be3247d4e8f37fcc5a5ecec2368073ae4e6b commit 04633df0c43d710e5f696b06539c100898678235 upstream. When we get loaded by a 64-bit bootloader, kernel entry point is startup_64 in head_64.S. We don't trust any and all bootloaders because some will fiddle with CPU configuration so we go ahead and massage each CPU into sanity again. For example, some dell BIOSes have this XD disable feature which set IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround for other OSes but Linux sure doesn't need it. A similar thing is present in the Surface 3 firmware - see https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit only on the BSP: # rdmsr -a 0x1a0 400850089 850089 850089 850089 I know, right?! There's not even an off switch in there. So fix all those cases by sanitizing the 64-bit entry point too. For that, make verify_cpu() callable in 64-bit mode also. Requested-and-debugged-by: "H. Peter Anvin" <hpa@zytor.com> Reported-and-tested-by: Bastien Nocera <bugzilla@hadess.net> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 04633df0c43d710e5f696b06539c100898678235 upstream.

When we get loaded by a 64-bit bootloader, kernel entry point is
startup_64 in head_64.S. We don't trust any and all bootloaders because
some will fiddle with CPU configuration so we go ahead and massage each
CPU into sanity again.

For example, some dell BIOSes have this XD disable feature which set
IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround
for other OSes but Linux sure doesn't need it.

A similar thing is present in the Surface 3 firmware - see
https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit
only on the BSP:

  # rdmsr -a 0x1a0
  400850089
  850089
  850089
  850089

I know, right?!

There's not even an off switch in there.

So fix all those cases by sanitizing the 64-bit entry point too. For
that, make verify_cpu() callable in 64-bit mode also.

Requested-and-debugged-by: "H. Peter Anvin" <hpa@zytor.com>
Reported-and-tested-by: Bastien Nocera <bugzilla@hadess.net>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
MIPS: atomic: Fix comment describing atomic64_add_unless's return value. 2015-11-27T12:48:21+00:00 Ralf Baechle ralf@linux-mips.org 2015-10-16T21:09:57+00:00 3ce1b9beb44fb0f7cc06ca86bf316071d43b7384 commit f25319d2cb439249a6859f53ad42ffa332b0acba upstream. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Fixes: f24219b4e90cf70ec4a211b17fbabc725a0ddf3c (cherry picked from commit f0a232cde7be18a207fd057dd79bbac8a0a45dec) Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit f25319d2cb439249a6859f53ad42ffa332b0acba upstream.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fixes: f24219b4e90cf70ec4a211b17fbabc725a0ddf3c
(cherry picked from commit f0a232cde7be18a207fd057dd79bbac8a0a45dec)
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: pxa: remove incorrect __init annotation on pxa27x_set_pwrmode 2015-11-27T12:48:20+00:00 Arnd Bergmann arnd@arndb.de 2015-10-12T13:46:08+00:00 df2ef64a3a36b91e374d7339cf53112f403d6164 commit 54c09889bff6d99c8733eed4a26c9391b177c88b upstream. The z2 machine calls pxa27x_set_pwrmode() in order to power off the machine, but this function gets discarded early at boot because it is marked __init, as pointed out by kbuild: WARNING: vmlinux.o(.text+0x145c4): Section mismatch in reference from the function z2_power_off() to the function .init.text:pxa27x_set_pwrmode() The function z2_power_off() references the function __init pxa27x_set_pwrmode(). This is often because z2_power_off lacks a __init annotation or the annotation of pxa27x_set_pwrmode is wrong. This removes the __init section modifier to fix rebooting and the build error. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: ba4a90a6d86a ("ARM: pxa/z2: fix building error of pxa27x_cpu_suspend() no longer available") Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 54c09889bff6d99c8733eed4a26c9391b177c88b upstream.

The z2 machine calls pxa27x_set_pwrmode() in order to power off
the machine, but this function gets discarded early at boot because
it is marked __init, as pointed out by kbuild:

WARNING: vmlinux.o(.text+0x145c4): Section mismatch in reference from the function z2_power_off() to the function .init.text:pxa27x_set_pwrmode()
The function z2_power_off() references
the function __init pxa27x_set_pwrmode().
This is often because z2_power_off lacks a __init
annotation or the annotation of pxa27x_set_pwrmode is wrong.

This removes the __init section modifier to fix rebooting and the
build error.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: ba4a90a6d86a ("ARM: pxa/z2: fix building error of pxa27x_cpu_suspend() no longer available")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>