linux/arch
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
..
alpha tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
arc arc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:21 +09:00
arm Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
arm64 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
blackfin Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
c6x Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
cris Kbuild updates for v4.13 (2nd) 2017-07-13 13:37:57 -07:00
frv FRV: tlbflush: move asmlinkage before return type 2017-07-12 16:26:04 -07:00
h8300 h8300: Add missing closing parenthesis in flat_get_addr_from_rp() 2017-07-16 09:24:06 -07:00
hexagon hexagon: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:26 +09:00
ia64 Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m32r Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m68k blackfin, m68k: Fix flat_set_persistent() for unsigned long to u32 changes 2017-07-16 09:24:06 -07:00
metag metag: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:30 +09:00
microblaze Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
mips tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
mn10300 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
nios2 nios2: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:43 +09:00
openrisc openrisc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:50 +09:00
parisc TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
powerpc TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
s390 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
score Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
sh TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
sparc TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
tile Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
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
unicore32 unicore32: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:52 +09:00
x86 x86/microcode/AMD: Free unneeded patch before exit from update_cache() 2017-07-25 11:26:19 +02:00
xtensa tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
.gitignore
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00