This is a note to let you know that I've just added the patch titled
sparc: Harden signal return frame checks.
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sparc-harden-signal-return-frame-checks.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Jun 20 10:48:29 PDT 2016
From: "David S. Miller" <davem@xxxxxxxxxxxxx>
Date: Sat, 28 May 2016 21:21:31 -0700
Subject: sparc: Harden signal return frame checks.
From: "David S. Miller" <davem@xxxxxxxxxxxxx>
[ Upstream commit d11c2a0de2824395656cf8ed15811580c9dd38aa ]
All signal frames must be at least 16-byte aligned, because that is
the alignment we explicitly create when we build signal return stack
frames.
All stack pointers must be at least 8-byte aligned.
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/sparc/kernel/signal32.c | 46 ++++++++++++++++++++++++++---------------
arch/sparc/kernel/signal_32.c | 41 +++++++++++++++++++++++-------------
arch/sparc/kernel/signal_64.c | 31 +++++++++++++++++----------
arch/sparc/kernel/sigutil_32.c | 9 +++++++-
arch/sparc/kernel/sigutil_64.c | 10 +++++++-
5 files changed, 92 insertions(+), 45 deletions(-)
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -138,12 +138,24 @@ int copy_siginfo_from_user32(siginfo_t *
return 0;
}
+/* Checks if the fp is valid. We always build signal frames which are
+ * 16-byte aligned, therefore we can always enforce that the restore
+ * frame has that property as well.
+ */
+static bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+ if ((((unsigned long) fp) & 15) ||
+ ((unsigned long)fp) > 0x100000000ULL - fplen)
+ return true;
+ return false;
+}
+
void do_sigreturn32(struct pt_regs *regs)
{
struct signal_frame32 __user *sf;
compat_uptr_t fpu_save;
compat_uptr_t rwin_save;
- unsigned int psr;
+ unsigned int psr, ufp;
unsigned pc, npc;
sigset_t set;
compat_sigset_t seta;
@@ -158,11 +170,16 @@ void do_sigreturn32(struct pt_regs *regs
sf = (struct signal_frame32 __user *) regs->u_regs[UREG_FP];
/* 1. Make sure we are not getting garbage from the user */
- if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
- (((unsigned long) sf) & 3))
+ if (invalid_frame_pointer(sf, sizeof(*sf)))
+ goto segv;
+
+ if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
+ goto segv;
+
+ if (ufp & 0x7)
goto segv;
- if (get_user(pc, &sf->info.si_regs.pc) ||
+ if (__get_user(pc, &sf->info.si_regs.pc) ||
__get_user(npc, &sf->info.si_regs.npc))
goto segv;
@@ -227,7 +244,7 @@ segv:
asmlinkage void do_rt_sigreturn32(struct pt_regs *regs)
{
struct rt_signal_frame32 __user *sf;
- unsigned int psr, pc, npc;
+ unsigned int psr, pc, npc, ufp;
compat_uptr_t fpu_save;
compat_uptr_t rwin_save;
sigset_t set;
@@ -242,11 +259,16 @@ asmlinkage void do_rt_sigreturn32(struct
sf = (struct rt_signal_frame32 __user *) regs->u_regs[UREG_FP];
/* 1. Make sure we are not getting garbage from the user */
- if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
- (((unsigned long) sf) & 3))
+ if (invalid_frame_pointer(sf, sizeof(*sf)))
goto segv;
- if (get_user(pc, &sf->regs.pc) ||
+ if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+ goto segv;
+
+ if (ufp & 0x7)
+ goto segv;
+
+ if (__get_user(pc, &sf->regs.pc) ||
__get_user(npc, &sf->regs.npc))
goto segv;
@@ -307,14 +329,6 @@ segv:
force_sig(SIGSEGV, current);
}
-/* Checks if the fp is valid */
-static int invalid_frame_pointer(void __user *fp, int fplen)
-{
- if ((((unsigned long) fp) & 7) || ((unsigned long)fp) > 0x100000000ULL - fplen)
- return 1;
- return 0;
-}
-
static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
{
unsigned long sp;
--- a/arch/sparc/kernel/signal_32.c
+++ b/arch/sparc/kernel/signal_32.c
@@ -60,10 +60,22 @@ struct rt_signal_frame {
#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
+/* Checks if the fp is valid. We always build signal frames which are
+ * 16-byte aligned, therefore we can always enforce that the restore
+ * frame has that property as well.
+ */
+static inline bool invalid_frame_pointer(void __user *fp, int fplen)
+{
+ if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
+ return true;
+
+ return false;
+}
+
asmlinkage void do_sigreturn(struct pt_regs *regs)
{
+ unsigned long up_psr, pc, npc, ufp;
struct signal_frame __user *sf;
- unsigned long up_psr, pc, npc;
sigset_t set;
__siginfo_fpu_t __user *fpu_save;
__siginfo_rwin_t __user *rwin_save;
@@ -77,10 +89,13 @@ asmlinkage void do_sigreturn(struct pt_r
sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
/* 1. Make sure we are not getting garbage from the user */
- if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
+ if (!invalid_frame_pointer(sf, sizeof(*sf)))
goto segv_and_exit;
- if (((unsigned long) sf) & 3)
+ if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
+ goto segv_and_exit;
+
+ if (ufp & 0x7)
goto segv_and_exit;
err = __get_user(pc, &sf->info.si_regs.pc);
@@ -127,7 +142,7 @@ segv_and_exit:
asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
{
struct rt_signal_frame __user *sf;
- unsigned int psr, pc, npc;
+ unsigned int psr, pc, npc, ufp;
__siginfo_fpu_t __user *fpu_save;
__siginfo_rwin_t __user *rwin_save;
sigset_t set;
@@ -135,8 +150,13 @@ asmlinkage void do_rt_sigreturn(struct p
synchronize_user_stack();
sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
- if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
- (((unsigned long) sf) & 0x03))
+ if (!invalid_frame_pointer(sf, sizeof(*sf)))
+ goto segv;
+
+ if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
+ goto segv;
+
+ if (ufp & 0x7)
goto segv;
err = __get_user(pc, &sf->regs.pc);
@@ -178,15 +198,6 @@ segv:
force_sig(SIGSEGV, current);
}
-/* Checks if the fp is valid */
-static inline int invalid_frame_pointer(void __user *fp, int fplen)
-{
- if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen))
- return 1;
-
- return 0;
-}
-
static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
{
unsigned long sp = regs->u_regs[UREG_FP];
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c
@@ -234,6 +234,17 @@ do_sigsegv:
goto out;
}
+/* Checks if the fp is valid. We always build rt signal frames which
+ * are 16-byte aligned, therefore we can always enforce that the
+ * restore frame has that property as well.
+ */
+static bool invalid_frame_pointer(void __user *fp)
+{
+ if (((unsigned long) fp) & 15)
+ return true;
+ return false;
+}
+
struct rt_signal_frame {
struct sparc_stackf ss;
siginfo_t info;
@@ -246,8 +257,8 @@ struct rt_signal_frame {
void do_rt_sigreturn(struct pt_regs *regs)
{
+ unsigned long tpc, tnpc, tstate, ufp;
struct rt_signal_frame __user *sf;
- unsigned long tpc, tnpc, tstate;
__siginfo_fpu_t __user *fpu_save;
__siginfo_rwin_t __user *rwin_save;
sigset_t set;
@@ -261,10 +272,16 @@ void do_rt_sigreturn(struct pt_regs *reg
(regs->u_regs [UREG_FP] + STACK_BIAS);
/* 1. Make sure we are not getting garbage from the user */
- if (((unsigned long) sf) & 3)
+ if (invalid_frame_pointer(sf))
+ goto segv;
+
+ if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
goto segv;
- err = get_user(tpc, &sf->regs.tpc);
+ if ((ufp + STACK_BIAS) & 0x7)
+ goto segv;
+
+ err = __get_user(tpc, &sf->regs.tpc);
err |= __get_user(tnpc, &sf->regs.tnpc);
if (test_thread_flag(TIF_32BIT)) {
tpc &= 0xffffffff;
@@ -308,14 +325,6 @@ segv:
force_sig(SIGSEGV, current);
}
-/* Checks if the fp is valid */
-static int invalid_frame_pointer(void __user *fp)
-{
- if (((unsigned long) fp) & 15)
- return 1;
- return 0;
-}
-
static inline void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs, unsigned long framesize)
{
unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
--- a/arch/sparc/kernel/sigutil_32.c
+++ b/arch/sparc/kernel/sigutil_32.c
@@ -48,6 +48,10 @@ int save_fpu_state(struct pt_regs *regs,
int restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
int err;
+
+ if (((unsigned long) fpu) & 3)
+ return -EFAULT;
+
#ifdef CONFIG_SMP
if (test_tsk_thread_flag(current, TIF_USEDFPU))
regs->psr &= ~PSR_EF;
@@ -97,7 +101,10 @@ int restore_rwin_state(__siginfo_rwin_t
struct thread_info *t = current_thread_info();
int i, wsaved, err;
- __get_user(wsaved, &rp->wsaved);
+ if (((unsigned long) rp) & 3)
+ return -EFAULT;
+
+ get_user(wsaved, &rp->wsaved);
if (wsaved > NSWINS)
return -EFAULT;
--- a/arch/sparc/kernel/sigutil_64.c
+++ b/arch/sparc/kernel/sigutil_64.c
@@ -37,7 +37,10 @@ int restore_fpu_state(struct pt_regs *re
unsigned long fprs;
int err;
- err = __get_user(fprs, &fpu->si_fprs);
+ if (((unsigned long) fpu) & 7)
+ return -EFAULT;
+
+ err = get_user(fprs, &fpu->si_fprs);
fprs_write(0);
regs->tstate &= ~TSTATE_PEF;
if (fprs & FPRS_DL)
@@ -72,7 +75,10 @@ int restore_rwin_state(__siginfo_rwin_t
struct thread_info *t = current_thread_info();
int i, wsaved, err;
- __get_user(wsaved, &rp->wsaved);
+ if (((unsigned long) rp) & 7)
+ return -EFAULT;
+
+ get_user(wsaved, &rp->wsaved);
if (wsaved > NSWINS)
return -EFAULT;
Patches currently in stable-queue which might be from davem@xxxxxxxxxxxxx are
queue-4.4/sparc64-fix-bootup-regressions-on-some-kconfig-combinations.patch
queue-4.4/bpf-inode-disallow-userns-mounts.patch
queue-4.4/vxlan-accept-user-specified-mtu-value-when-create-new-vxlan-link.patch
queue-4.4/sfc-on-mc-reset-clear-pio-buffer-linkage-in-txqs.patch
queue-4.4/ipv6-skip-xfrm-lookup-if-dst_entry-in-socket-cache-is-valid.patch
queue-4.4/l2tp-fix-configuration-passed-to-setup_udp_tunnel_sock.patch
queue-4.4/switchdev-pass-pointer-to-fib_info-instead-of-copy.patch
queue-4.4/vxlan-relax-mtu-constraints.patch
queue-4.4/sparc-fix-system-call-tracing-register-handling.patch
queue-4.4/vxlan-gre-geneve-set-a-large-mtu-on-ovs-created-tunnel-devices.patch
queue-4.4/tcp-record-tlp-and-er-timer-stats-in-v6-stats.patch
queue-4.4/sparc64-fix-return-from-trap-window-fill-crashes.patch
queue-4.4/bpf-use-mount_nodev-not-mount_ns-to-mount-the-bpf-filesystem.patch
queue-4.4/netlink-fix-dump-skb-leak-double-free.patch
queue-4.4/sparc-pci-fix-for-panic-while-enabling-sr-iov.patch
queue-4.4/team-don-t-call-netdev_change_features-under-team-lock.patch
queue-4.4/sparc64-reduce-tlb-flushes-during-hugepte-changes.patch
queue-4.4/udp-prevent-skbs-lingering-in-tunnel-socket-queues.patch
queue-4.4/bridge-don-t-insert-unnecessary-local-fdb-entry-on-changing-mac-address.patch
queue-4.4/tipc-fix-nametable-publication-field-in-nl-compat.patch
queue-4.4/sparc64-fix-sparc64_set_context-stack-handling.patch
queue-4.4/sparc64-take-ctx_alloc_lock-properly-in-hugetlb_setup.patch
queue-4.4/tipc-check-nl-sock-before-parsing-nested-attributes.patch
queue-4.4/geneve-relax-mtu-constraints.patch
queue-4.4/uapi-glibc-compat-fix-compilation-when-__use_misc-in-glibc.patch
queue-4.4/sparc-harden-signal-return-frame-checks.patch
queue-4.4/tuntap-correctly-wake-up-process-during-uninit.patch
queue-4.4/sparc64-fix-numa-node-distance-initialization.patch
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