From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Robert OCallahan <robert@ocallahan.org>,
Yu-cheng Yu <yu-cheng.yu@intel.com>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@suse.de>,
David Hansen <dave.hansen@linux.intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 4.8 18/37] x86/fpu: Fix invalid FPU ptrace state after execve()
Date: Wed, 30 Nov 2016 10:29:55 +0100 [thread overview]
Message-ID: <20161130092730.621591124@linuxfoundation.org> (raw)
In-Reply-To: <20161130092729.623248210@linuxfoundation.org>
4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yu-cheng Yu <yu-cheng.yu@intel.com>
commit b22cbe404a9cc3c7949e380fa1861e31934c8978 upstream.
Robert O'Callahan reported that after an execve PTRACE_GETREGSET
NT_X86_XSTATE continues to return the pre-exec register values
until the exec'ed task modifies FPU state.
The test code is at:
https://bugzilla.redhat.com/attachment.cgi?id=1164286.
What is happening is fpu__clear() does not properly clear fpstate.
Fix it by doing just that.
Reported-by: Robert O'Callahan <robert@ocallahan.org>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1479402695-6553-1-git-send-email-yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/fpu/core.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -517,14 +517,14 @@ void fpu__clear(struct fpu *fpu)
{
WARN_ON_FPU(fpu != ¤t->thread.fpu); /* Almost certainly an anomaly */
- if (!use_eager_fpu() || !static_cpu_has(X86_FEATURE_FPU)) {
- /* FPU state will be reallocated lazily at the first use. */
- fpu__drop(fpu);
- } else {
- if (!fpu->fpstate_active) {
- fpu__activate_curr(fpu);
- user_fpu_begin();
- }
+ fpu__drop(fpu);
+
+ /*
+ * Make sure fpstate is cleared and initialized.
+ */
+ if (static_cpu_has(X86_FEATURE_FPU)) {
+ fpu__activate_curr(fpu);
+ user_fpu_begin();
copy_init_fpstate_to_fpregs();
}
}
next prev parent reply other threads:[~2016-11-30 9:57 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20161130093010epcas2p3047cf63814e74dfcc79f43d37b446ae0@epcas2p3.samsung.com>
2016-11-30 9:29 ` [PATCH 4.8 00/37] 4.8.12-stable review Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 07/37] usb: chipidea: move the lock initialization to core file Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 08/37] USB: serial: cp210x: add ID for the Zone DPMX Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 09/37] USB: serial: ftdi_sio: add support for TI CC3200 LaunchPad Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 10/37] Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 11/37] scsi: mpt3sas: Fix secure erase premature termination Greg Kroah-Hartman
2016-11-30 16:49 ` Martin K. Petersen
2016-12-01 7:10 ` Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 12/37] tile: avoid using clocksource_cyc2ns with absolute cycle count Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 13/37] cfg80211: limit scan results cache size Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 15/37] drm/radeon: fix power state when port pm is unavailable (v2) Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 16/37] apparmor: fix change_hat not finding hat after policy replacement Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 17/37] NFSv4.x: hide array-bounds warning Greg Kroah-Hartman
2016-11-30 9:29 ` Greg Kroah-Hartman [this message]
2016-11-30 9:29 ` [PATCH 4.8 19/37] x86/traps: Ignore high word of regs->cs in early_fixup_exception() Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 20/37] perf/core: Fix address filter parser Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 21/37] perf/x86/intel: Cure bogus unwind from PEBS entries Greg Kroah-Hartman
2016-11-30 9:29 ` [PATCH 4.8 22/37] thermal/powerclamp: add back module device table Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 23/37] parisc: Fix races in parisc_setup_cache_timing() Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 24/37] parisc: Switch to generic sched_clock implementation Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 25/37] parisc: Fix race in pci-dma.c Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 26/37] parisc: Also flush data TLB in flush_icache_page_asm Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 27/37] mmc: sdhci-of-esdhc: fixup PRESENT_STATE read Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 28/37] mpi: Fix NULL ptr dereference in mpi_powm() [ver #3] Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 29/37] X.509: Fix double free in x509_cert_parse() " Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 30/37] xc2028: Fix use-after-free bug properly Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 31/37] device-dax: check devm_nsio_enable() return value Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 32/37] device-dax: fail all private mapping attempts Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 33/37] powerpc: Set missing wakeup bit in LPCR on POWER9 Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 34/37] powerpc/mm: Fixup kernel read only mapping Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 35/37] powerpc/boot: Fix the early OPAL console wrappers Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 36/37] can: bcm: fix support for CAN FD frames Greg Kroah-Hartman
2016-11-30 9:30 ` [PATCH 4.8 37/37] mm, oom: stop pre-mature high-order OOM killer invocations Greg Kroah-Hartman
[not found] ` <20161130092730.460938123@linuxfoundation.org>
2016-11-30 10:51 ` [PATCH 4.8 14/37] drm/amdgpu: fix power state when port pm is unavailable Peter Wu
2016-11-30 11:53 ` Greg Kroah-Hartman
2016-12-05 0:11 ` Peter Wu
2016-12-05 14:46 ` Greg Kroah-Hartman
2016-11-30 16:04 ` [PATCH 4.8 00/37] 4.8.12-stable review Shuah Khan
2016-12-01 7:14 ` Greg Kroah-Hartman
2016-11-30 23:34 ` Guenter Roeck
2016-12-01 7:15 ` Greg Kroah-Hartman
[not found] ` <583ed167.6602c20a.c3129.a6b8@mx.google.com>
[not found] ` <m2oa0wkjlk.fsf@baylibre.com>
2016-12-01 7:11 ` Greg Kroah-Hartman
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