This is a note to let you know that I've just added the patch titled
x86/intel_rdt/cqm: Prevent use after free
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-intel_rdt-cqm-prevent-use-after-free.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From d47924417319e3b6a728c0b690f183e75bc2a702 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner tglx@linutronix.de Date: Tue, 16 Jan 2018 19:59:59 +0100 Subject: x86/intel_rdt/cqm: Prevent use after free
From: Thomas Gleixner tglx@linutronix.de
commit d47924417319e3b6a728c0b690f183e75bc2a702 upstream.
intel_rdt_iffline_cpu() -> domain_remove_cpu() frees memory first and then proceeds accessing it.
BUG: KASAN: use-after-free in find_first_bit+0x1f/0x80 Read of size 8 at addr ffff883ff7c1e780 by task cpuhp/31/195 find_first_bit+0x1f/0x80 has_busy_rmid+0x47/0x70 intel_rdt_offline_cpu+0x4b4/0x510
Freed by task 195: kfree+0x94/0x1a0 intel_rdt_offline_cpu+0x17d/0x510
Do the teardown first and then free memory.
Fixes: 24247aeeabe9 ("x86/intel_rdt/cqm: Improve limbo list processing") Reported-by: Joseph Salisbury joseph.salisbury@canonical.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Ravi Shankar ravi.v.shankar@intel.com Cc: Peter Zilstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Cc: Vikas Shivappa vikas.shivappa@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: "Roderick W. Smith" rod.smith@canonical.com Cc: 1733662@bugs.launchpad.net Cc: Fenghua Yu fenghua.yu@intel.com Cc: Tony Luck tony.luck@intel.com Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801161957510.2366@nanos Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/intel_rdt.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -525,10 +525,6 @@ static void domain_remove_cpu(int cpu, s */ if (static_branch_unlikely(&rdt_mon_enable_key)) rmdir_mondata_subdir_allrdtgrp(r, d->id); - kfree(d->ctrl_val); - kfree(d->rmid_busy_llc); - kfree(d->mbm_total); - kfree(d->mbm_local); list_del(&d->list); if (is_mbm_enabled()) cancel_delayed_work(&d->mbm_over); @@ -545,6 +541,10 @@ static void domain_remove_cpu(int cpu, s cancel_delayed_work(&d->cqm_limbo); }
+ kfree(d->ctrl_val); + kfree(d->rmid_busy_llc); + kfree(d->mbm_total); + kfree(d->mbm_local); kfree(d); return; }
Patches currently in stable-queue which might be from tglx@linutronix.de are
queue-4.14/futex-prevent-overflow-by-strengthen-input-validation.patch queue-4.14/objtool-fix-clang-enum-conversion-warning.patch queue-4.14/timers-unconditionally-check-deferrable-base.patch queue-4.14/objtool-improve-error-message-for-bad-file-argument.patch queue-4.14/futex-avoid-violating-the-10th-rule-of-futex.patch queue-4.14/objtool-fix-seg-fault-with-gold-linker.patch queue-4.14/x86-mm-pkeys-fix-fill_sig_info_pkey.patch queue-4.14/x86-tsc-fix-erroneous-tsc-rate-on-skylake-xeon.patch queue-4.14/module-add-retpoline-tag-to-vermagic.patch queue-4.14/x86-kasan-panic-if-there-is-not-enough-memory-to-boot.patch queue-4.14/x86-idt-mark-idt-tables-__initconst.patch queue-4.14/x86-retpoline-fill-rsb-on-context-switch-for-affected-cpus.patch queue-4.14/delayacct-account-blkio-completion-on-the-correct-task.patch queue-4.14/x86-tsc-future-proof-native_calibrate_tsc.patch queue-4.14/objtool-fix-seg-fault-with-clang-compiled-objects.patch queue-4.14/x86-retpoline-add-lfence-to-the-retpoline-rsb-filling-rsb-macros.patch queue-4.14/x86-cpufeature-move-processor-tracing-out-of-scattered-features.patch queue-4.14/x86-intel_rdt-cqm-prevent-use-after-free.patch queue-4.14/objtool-fix-seg-fault-caused-by-missing-parameter.patch