linux_dsm_epyc7002/arch/x86
Shu Wang a99f03428f x86/microcode/AMD: Free unneeded patch before exit from update_cache()
verify_and_add_patch() allocates memory for a microcode patch and hands
it down to be added to the cache of patches. However, if the cache
already has the latest patch, the newly allocated one needs to be freed
before returning. Do that.

This issue has been found by kmemleak:

  unreferenced object 0xffff88010e780b40 (size 32):
    comm "bash", pid 860, jiffies 4294690939 (age 29.297s)
    backtrace:
       kmemleak_alloc
       kmem_cache_alloc_trace
       load_microcode_amd.isra.0
       request_microcode_amd
       reload_store
       dev_attr_store
       sysfs_kf_write
       kernfs_fop_write
       __vfs_write
       vfs_write
       SyS_write
       do_syscall_64
       return_from_SYSCALL_64
       0xffffffffffffffff

  (gdb) list *0xffffffff81050d60
  0xffffffff81050d60 is in load_microcode_amd
                (arch/x86/kernel/cpu/microcode/amd.c:616).

which is this:

	patch = kzalloc(sizeof(*patch), GFP_KERNEL);
-->	if (!patch) {
		pr_err("Patch allocation failure.\n");
		return -EINVAL;
	}

Signed-off-by: Shu Wang <shuwang@redhat.com>
[ Rewrite commit message. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chuhu@redhat.com
Cc: liwang@redhat.com
Link: http://lkml.kernel.org/r/20170724101228.17326-2-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-25 11:26:19 +02:00
..
boot x86/build: Silence the build with "make -s" 2017-07-20 10:46:24 +02:00
configs x86/defconfig: Remove stale, old Kconfig options 2017-07-20 10:28:19 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-07-14 22:49:50 -07:00
entry Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-07-08 12:17:25 -07:00
events Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 11:20:58 -07:00
hyperv char/misc patches for 4.12-rc1 2017-05-04 19:15:35 -07:00
ia32 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
include Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 11:20:58 -07:00
kernel x86/microcode/AMD: Free unneeded patch before exit from update_cache() 2017-07-25 11:26:19 +02:00
kvm kvm: x86: hyperv: avoid livelock in oneshot SynIC timers 2017-07-20 17:00:00 +02:00
lguest Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 20:51:12 -07:00
lib include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00
math-emu x86/fpu/math-emu: Avoid bogus -Wint-in-bool-context warning 2017-07-20 10:46:24 +02:00
mm x86/mmap: properly account for stack randomization in mmap_base 2017-07-12 16:26:03 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
oprofile
pci pci-v4.13-changes 2017-07-08 15:51:57 -07:00
platform x86/platform/uv/BAU: Disable BAU on single hub configurations 2017-07-21 09:56:25 +02:00
power x86/boot/e820: Introduce the bootloader provided e820_table_firmware[] table 2017-07-05 10:09:02 +02:00
purgatory kasan: do not sanitize kexec purgatory 2017-03-31 17:13:30 -07:00
ras x86/mce: Merge mce_amd_inj into mce-inject 2017-06-14 07:32:07 +02:00
realmode x86/boot/64: Rename init_level4_pgt and early_level4_pgt 2017-06-13 08:56:55 +02:00
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Merge branch 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-07-15 10:49:33 -07:00
video
xen xen/x86: fix cpu hotplug 2017-07-23 08:13:11 +02:00
.gitignore
Kbuild Drivers: hv vmbus: Move Hypercall page setup out of common code 2017-01-19 11:42:07 +01:00
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00
Kconfig.cpu
Kconfig.debug x86/platform: Add PCI dependency for PUNIT_ATOM_DEBUG 2017-07-20 10:46:24 +02:00
Makefile Kbuild updates for v4.13 2017-07-07 14:09:24 -07:00
Makefile_32.cpu kbuild: remove cc-option-align 2017-06-25 12:43:00 +09:00
Makefile.um