WSL2-Linux-Kernel/lib
Andrey Ryabinin f5527fffff mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
This fixes CVE-2016-8650.

If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus.  However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.

Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.

This affects the use of RSA keys and X.509 certificates that carry them.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[<ffffffff8138ce5d>]  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8  EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS:  00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
 ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
 [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66
 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d
 [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd
 [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146
 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee
 [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb
 [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1
 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228
 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4
 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1
 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1
 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61
 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399
 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e
 [<ffffffff81001c2b>] do_syscall_64+0x80/0x191
 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
 RSP <ffff880401297ad8>
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---

Basically, this is a backport of a libgcrypt patch:

	http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526

Fixes: cdec9cb516 ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
cc: linux-ima-devel@lists.sourceforge.net
cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-11-25 12:57:50 +11:00
..
842
fonts
lz4
lzo
mpi mpi: Fix NULL ptr dereference in mpi_powm() [ver #3] 2016-11-25 12:57:50 +11:00
raid6 Merge tag 'md/4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md 2016-10-07 09:45:43 -07:00
reed_solomon
xz
zlib_deflate
zlib_inflate
.gitignore
Kconfig Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
Kconfig.debug config: Adding the new config parameter CONFIG_PROVE_LOCKING_SMALL for sparc 2016-11-18 11:33:19 -08:00
Kconfig.kasan mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
Kconfig.kgdb
Kconfig.kmemcheck
Kconfig.ubsan ubsan: allow to disable the null sanitizer 2016-09-20 14:26:08 +02:00
Makefile kcov: do not instrument lib/stackdepot.c 2016-10-11 15:06:32 -07:00
argv_split.c
asn1_decoder.c
assoc_array.c
atomic64.c
atomic64_test.c atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 2016-10-07 18:46:30 -07:00
audit.c
bcd.c
bch.c
bitmap.c lib/bitmap.c: enhance bitmap syntax 2016-10-11 15:06:30 -07:00
bitrev.c
bsearch.c
btree.c
bug.c
build_OID_registry
bust_spinlocks.c
chacha20.c
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
compat_audit.c
cordic.c
cpu-notifier-error-inject.c fault-injection/cpu: Convert to hotplug state machine 2016-09-19 21:44:31 +02:00
cpu_rmap.c
cpumask.c
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc7.c
crc8.c
crc16.c
crc32.c crc32: use ktime_get_ns() for measurement 2016-08-02 19:35:08 -04:00
crc32defs.h
ctype.c
debug_info.c
debug_locks.c
debugobjects.c
dec_and_lock.c
decompress.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
devres.c
digsig.c
div64.c
dma-debug.c dmaengine updates for 4.8-rc1 2016-10-06 17:13:54 -07:00
dma-noop.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
dump_stack.c
dynamic_debug.c dynamic_debug: add jump label support 2016-08-04 08:50:07 -04:00
dynamic_queue_limits.c
earlycpio.c
extable.c
fault-inject.c
fdt.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c
flex_array.c
flex_proportions.c
gcd.c
gen_crc32table.c
genalloc.c lib/genalloc.c: start search from start of chunk 2016-10-27 18:43:43 -07:00
glob.c
halfmd4.c
hexdump.c
hweight.c
idr.c
inflate.c
int_sqrt.c
interval_tree.c
interval_tree_test.c
iomap.c
iomap_copy.c
iommu-common.c
iommu-helper.c lib/iommu-helper: skip to next segment 2016-08-02 19:35:07 -04:00
ioremap.c
iov_iter.c fix iov_iter_advance() for ITER_PIPE 2016-11-17 00:00:48 -05:00
irq_poll.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
kfifo.c
klist.c
kobject.c
kobject_uevent.c
kstrtox.c lib/kstrtox.c: smaller _parse_integer() 2016-10-11 15:06:30 -07:00
kstrtox.h
lcm.c
libcrc32c.c
list_debug.c
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c
lru_cache.c
md5.c
memory-notifier-error-inject.c
memweight.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
parser.c
pci_iomap.c
percpu-refcount.c percpu-refcount: init ->confirm_switch member properly 2016-08-11 13:52:23 -04:00
percpu_counter.c
percpu_ida.c
percpu_test.c
plist.c
pm-notifier-error-inject.c
radix-tree.c mm: filemap: don't plant shadow entries without radix tree node 2016-10-05 09:17:56 -07:00
random32.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
ratelimit.c ratelimit: extend to print suppressed messages on release 2016-08-02 19:35:06 -04:00
rational.c
rbtree.c
rbtree_test.c
reciprocal_div.c
rhashtable.c rhashtable: Add rhlist interface 2016-09-20 04:43:36 -04:00
sbitmap.c sbitmap: initialize weight to zero 2016-09-19 08:19:40 -06:00
scatterlist.c
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
show_mem.c
smp_processor_id.c
sort.c
stackdepot.c lib/stackdepot: export save/fetch stack for drivers 2016-11-11 08:12:37 -08:00
stmp_device.c
string.c
string_helpers.c
strncpy_from_user.c lib: harden strncpy_from_user 2016-10-11 15:06:30 -07:00
strnlen_user.c unsafe_[get|put]_user: change interface to use a error target label 2016-08-08 13:02:01 -07:00
swiotlb.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
syscall.c lib/syscall: Pin the task stack in collect_syscall() 2016-09-16 09:18:53 +02:00
test-kstrtox.c
test-string_helpers.c
test_bitmap.c
test_bpf.c bpf, test: fix ld_abs + vlan push/pop stress test 2016-10-20 14:39:06 -04:00
test_firmware.c
test_hash.c lib/test_hash.c: fix warning in preprocessor symbol evaluation 2016-09-01 17:52:01 -07:00
test_hexdump.c
test_kasan.c
test_module.c
test_printf.c
test_rhashtable.c rhashtable-test: Fix max_size parameter description 2016-08-08 12:52:42 -07:00
test_static_key_base.c
test_static_keys.c
test_user_copy.c
test_uuid.c
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c UBSAN: fix typo in format string 2016-08-02 17:31:41 -04:00
ubsan.h
ucs2_string.c lib/ucs2_string: Speed up ucs2_utf8size() 2016-09-09 16:08:46 +01:00
uuid.c
vsprintf.c
win_minmax.c lib/win_minmax: windowed min or max estimator 2016-09-21 00:22:59 -04:00