Eric Biggers 8ea52a683f KEYS: fix NULL pointer dereference during ASN.1 parsing [ver #2] ...

commit 624f5ab8720b3371367327a822c267699c1823b8 upstream.

syzkaller reported a NULL pointer dereference in asn1_ber_decoder().  It
can be reproduced by the following command, assuming
CONFIG_PKCS7_TEST_KEY=y:

        keyctl add pkcs7_test desc '' @s

The bug is that if the data buffer is empty, an integer underflow occurs
in the following check:

        if (unlikely(dp >= datalen - 1))
                goto data_overrun_error;

This results in the NULL data pointer being dereferenced.

Fix it by checking for 'datalen - dp < 2' instead.

Also fix the similar check for 'dp >= datalen - n' later in the same
function.  That one possibly could result in a buffer overread.

The NULL pointer dereference was reproducible using the "pkcs7_test" key
type but not the "asymmetric" key type because the "asymmetric" key type
checks for a 0-length payload before calling into the ASN.1 decoder but
the "pkcs7_test" key type does not.

The bug report was:

    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    PGD 7b708067 P4D 7b708067 PUD 7b6ee067 PMD 0
    Oops: 0000 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 522 Comm: syz-executor1 Not tainted 4.14.0-rc8 #7
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.3-20171021_125229-anatol 04/01/2014
    task: ffff9b6b3798c040 task.stack: ffff9b6b37970000
    RIP: 0010:asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    RSP: 0018:ffff9b6b37973c78 EFLAGS: 00010216
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000021c
    RDX: ffffffff814a04ed RSI: ffffb1524066e000 RDI: ffffffff910759e0
    RBP: ffff9b6b37973d60 R08: 0000000000000001 R09: ffff9b6b3caa4180
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
    FS:  00007f10ed1f2700(0000) GS:ffff9b6b3ea00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000007b6f3000 CR4: 00000000000006f0
    Call Trace:
     pkcs7_parse_message+0xee/0x240 crypto/asymmetric_keys/pkcs7_parser.c:139
     verify_pkcs7_signature+0x33/0x180 certs/system_keyring.c:216
     pkcs7_preparse+0x41/0x70 crypto/asymmetric_keys/pkcs7_key_type.c:63
     key_create_or_update+0x180/0x530 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0xbf/0x250 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x4585c9
    RSP: 002b:00007f10ed1f1bd8 EFLAGS: 00000216 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007f10ed1f2700 RCX: 00000000004585c9
    RDX: 0000000020000000 RSI: 0000000020008ffb RDI: 0000000020008000
    RBP: 0000000000000000 R08: ffffffffffffffff R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000216 R12: 00007fff1b2260ae
    R13: 00007fff1b2260af R14: 00007f10ed1f2700 R15: 0000000000000000
    Code: dd ca ff 48 8b 45 88 48 83 e8 01 4c 39 f0 0f 86 a8 07 00 00 e8 53 dd ca ff 49 8d 46 01 48 89 85 58 ff ff ff 48 8b 85 60 ff ff ff <42> 0f b6 0c 30 89 c8 88 8d 75 ff ff ff 83 e0 1f 89 8d 28 ff ff
    RIP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233 RSP: ffff9b6b37973c78
    CR2: 0000000000000000

Fixes: 42d5ec27f873 ("X.509: Add an ASN.1 decoder")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2017-11-15 15:53:18 +01:00

..

842

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2016-03-17 21:38:27 -07:00

fonts

fonts: Add 6x10 font

2014-10-09 11:35:48 +03:00

lz4

lz4: fix bogus gcc warning

2017-09-02 07:07:54 +02:00

lzo

lzo: check for length overrun in variable length encoding.

2014-09-28 11:08:01 +02:00

mpi

lib/mpi: kunmap after finishing accessing buffer

2017-09-07 08:35:40 +02:00

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

lib/xz: enable all filters by default in Kconfig

2014-06-04 16:54:18 -07:00

zlib_deflate

zlib_deflate/deftree: remove bi_reverse()

2015-09-10 13:29:01 -07:00

zlib_inflate

zlib: clean up some dead code

2014-08-06 18:01:24 -07:00

.gitignore

…

argv_split.c

…

asn1_decoder.c

KEYS: fix NULL pointer dereference during ASN.1 parsing [ver #2]

2017-11-15 15:53:18 +01:00

assoc_array.c

assoc_array: Fix a buggy node-splitting case

2017-11-02 09:49:14 +01:00

atomic64_test.c

atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE

2016-10-07 18:46:30 -07:00

atomic64.c

locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()

2016-06-16 10:48:32 +02:00

audit.c

syscalls: implement execveat() system call

2014-12-13 12:42:51 -08:00

bcd.c

…

bch.c

…

bitmap.c

lib/bitmap.c: enhance bitmap syntax

2016-10-11 15:06:30 -07:00

bitrev.c

ARM: 8187/1: add CONFIG_HAVE_ARCH_BITREVERSE to support rbit instruction

2014-12-22 16:43:06 +00:00

bsearch.c

…

btree.c

treewide: Remove old email address

2015-11-23 09:44:58 +01:00

bug.c

lib/bug.c: use common WARN helper

2016-03-17 15:09:34 -07:00

build_OID_registry

…

bust_spinlocks.c

…

chacha20.c

random: replace non-blocking pool with a Chacha20-based CRNG

2016-07-03 00:57:23 -04:00

check_signature.c

…

checksum.c

ipv4: Update parameters for csum_tcpudp_magic to their original types

2016-03-13 23:55:13 -04:00

clz_ctz.c

lib/clz_ctz.c: add prototype declarations in lib/clz_ctz.c

2014-04-03 16:21:12 -07:00

clz_tab.c

…

cmdline.c

lib/cmdline.c: fix get_options() overflow while parsing ranges

2017-06-29 13:00:28 +02:00

compat_audit.c

audit: Add generic compat syscall support

2014-03-20 10:11:35 -04:00

cordic.c

…

cpu_rmap.c

sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask()

2015-05-27 15:22:15 +02:00

cpu-notifier-error-inject.c

fault-injection/cpu: Convert to hotplug state machine

2016-09-19 21:44:31 +02:00

cpumask.c

sched/fair, cpumask: Export for_each_cpu_wrap()

2017-07-21 07:42:23 +02:00

crc7.c

lib/crc7: Shift crc7() output left 1 bit

2014-05-16 14:26:52 -04:00

crc8.c

…

crc16.c

…

crc32.c

crc32: use ktime_get_ns() for measurement

2016-08-02 19:35:08 -04:00

crc32defs.h

…

crc-ccitt.c

…

crc-itu-t.c

lib: crc-itu-t.[ch] fix 0x0x prefix in integer constants

2015-05-26 15:26:43 +02:00

crc-t10dif.c

lib: introduce crc_t10dif_update()

2015-05-30 22:42:24 -07:00

ctype.c

…

debug_info.c

kbuild: include core debug info when DEBUG_INFO_REDUCED

2015-06-11 15:08:32 +02:00

debug_locks.c

…

debugobjects.c

lib/debugobjects: export for use in modules

2016-11-30 16:32:52 -08:00

dec_and_lock.c

…

decompress_bunzip2.c

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10 13:29:01 -07:00

decompress_inflate.c

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10 13:29:01 -07:00

decompress_unlz4.c

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10 13:29:01 -07:00

decompress_unlzma.c

lib/decompress_unlzma: Do a NULL check for pointer

2015-09-10 13:29:01 -07:00

decompress_unlzo.c

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10 13:29:01 -07:00

decompress_unxz.c

lib/decompressors: use real out buf size for gunzip with kernel

2015-09-10 13:29:01 -07:00

decompress.c

lib/decompress: set the compressor name to NULL on error

2015-07-17 16:39:54 -07:00

devres.c

devres: use to_pci_dev()

2016-02-07 23:17:59 -08:00

digsig.c

lib/digsig: fix dereference of NULL user_key_payload

2017-10-27 10:38:08 +02:00

div64.c

__div64_32(): make it overridable at compile time

2015-11-16 14:42:12 -05:00

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

dump_stack: avoid potential deadlocks

2016-02-05 18:10:40 -08:00

dynamic_debug.c

dynamic_debug: add jump label support

2016-08-04 08:50:07 -04:00

dynamic_queue_limits.c

lib/dynamic_queue_limits.c: simplify includes

2015-02-12 18:54:15 -08:00

earlycpio.c

lib/cpio: Make find_cpio_data()'s offset arg optional

2016-06-08 11:04:19 +02:00

extable.c

extable: add support for relative extables to search and sort routines

2016-02-24 14:57:26 +00:00

fault-inject.c

fault-inject: fix inverted interval/probability values in printk

2015-10-23 17:55:10 +09:00

fdt_empty_tree.c

lib: add fdt_empty_tree.c

2014-04-30 19:49:37 +01:00

fdt_ro.c

…

fdt_rw.c

…

fdt_strerror.c

…

fdt_sw.c

…

fdt_wip.c

…

fdt.c

…

find_bit.c

lib: rename lib/find_next_bit.c to lib/find_bit.c

2015-04-17 09:03:54 -04:00

flex_array.c

reciprocal_divide: update/correction of the algorithm

2014-01-21 23:17:20 -08:00

flex_proportions.c

lib+mm: fix few spelling mistakes

2016-02-15 11:18:23 +01:00

gcd.c

lib/GCD.c: use binary GCD algorithm instead of Euclidean

2016-05-20 17:58:30 -07:00

gen_crc32table.c

lib: crc32: constify crc32 lookup table

2015-02-13 21:21:35 -08:00

genalloc.c

lib/genalloc.c: start search from start of chunk

2016-10-27 18:43:43 -07:00

glob.c

lib/glob.c: add CONFIG_GLOB_SELFTEST

2014-08-06 18:01:25 -07:00

halfmd4.c

lib/halfmd4.c: use rol32 inline function in the ROUND macro

2015-11-06 17:50:42 -08:00

hexdump.c

lib/hexdump.c: truncate output in case of overflow

2015-11-06 17:50:42 -08:00

hweight.c

x86/hweight: Get rid of the special calling convention

2016-06-08 15:01:02 +02:00

idr.c

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

2015-11-06 17:50:42 -08:00

inflate.c

…

int_sqrt.c

…

interval_tree_test.c

lib: Export interval_tree

2014-05-05 09:09:14 +02:00

interval_tree.c

lib/interval_tree.c: simplify includes

2015-02-12 18:54:15 -08:00

iomap_copy.c

lib/iomap_copy.c: add __ioread32_copy()

2016-01-20 17:09:18 -08:00

iomap.c

Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP

2014-04-07 16:36:11 -07:00

iommu-common.c

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc

2015-11-05 16:34:48 -08:00

iommu-helper.c

lib/iommu-helper: skip to next segment

2016-08-02 19:35:07 -04:00

ioremap.c

x86, mm: support huge KVA mappings on x86

2015-04-14 16:49:04 -07:00

iov_iter.c

new privimitive: iov_iter_revert()

2017-04-21 09:31:21 +02:00

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

lib/is_single_threaded.c: change current_is_single_threaded() to use for_each_thread()

2015-11-06 17:50:42 -08:00

jedec_ddr_data.c

…

kasprintf.c

lib/kasprintf.c: add sanity check to kvasprintf

2016-01-16 11:17:27 -08:00

Kconfig

Merge branch 'akpm' (patches from Andrew)

2016-10-07 21:38:00 -07:00

Kconfig.debug

lib/Kconfig.debug: fix frv build failure

2017-08-11 08:49:36 -07:00

Kconfig.kasan

mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB

2016-07-28 16:07:41 -07:00

Kconfig.kgdb

kgdb: depends on VT

2016-05-23 17:04:14 -07:00

Kconfig.kmemcheck

…

Kconfig.ubsan

ubsan: allow to disable the null sanitizer

2016-09-20 14:26:08 +02:00

kfifo.c

kfifo: use BUG_ON

2014-08-08 15:57:25 -07:00

klist.c

klist: fix starting point removed bug in klist iterators

2016-02-07 22:18:47 -08:00

kobject_uevent.c

lib/kobject_uevent.c: remove redundant include

2015-02-12 18:54:15 -08:00

kobject.c

kobject: export kset_find_obj() for module use

2016-02-09 17:36:34 -08:00

kstrtox.c

lib/kstrtox.c: smaller _parse_integer()

2016-10-11 15:06:30 -07:00

kstrtox.h

…

lcm.c

block: fix blk_stack_limits() regression due to lcm() change

2015-03-31 09:45:50 -06:00

libcrc32c.c

crypto: Work around deallocated stack frame reference gcc bug on sparc.

2017-06-24 07:11:17 +02:00

list_debug.c

list: kill list_force_poison()

2016-03-09 15:43:42 -08:00

list_sort.c

lib/list_sort: use late_initcall to hook in self tests

2015-06-16 14:12:35 -04:00

llist.c

lib/llist.c: fix data race in llist_del_first

2015-11-06 17:50:42 -08:00

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

locking/selftest: Fix output since KERN_CONT changes

2016-11-25 07:12:19 +01:00

lockref.c

locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition

2015-08-12 11:59:04 +02:00

lru_cache.c

lru_cache: Converted lc_seq_printf_status to return void

2015-11-25 09:22:02 -07:00

Makefile

kcov: do not instrument lib/stackdepot.c

2016-10-11 15:06:32 -07:00

md5.c

lib/md5.c: simplify include

2015-02-12 18:54:15 -08:00

memory-notifier-error-inject.c

…

memweight.c

…

net_utils.c

mac_pton: Use bool not int return

2014-06-25 17:45:43 -07:00

netdev-notifier-error-inject.c

net: Add support for CHANGEUPPER notifier error injection

2015-12-03 11:49:23 -05:00

nlattr.c

libnl: fix help of _64bit functions

2016-04-23 20:13:24 -04:00

nmi_backtrace.c

nmi_backtrace: generate one-line reports for idle cpus

2016-10-07 18:46:30 -07:00

nodemask.c

include/linux/nodemask.h: create next_node_in() helper

2016-05-19 19:12:14 -07:00

notifier-error-inject.c

…

notifier-error-inject.h

…

of-reconfig-notifier-error-inject.c

…

oid_registry.c

…

once.c

once: make helper generic for calling functions once

2015-10-08 05:26:36 -07:00

parser.c

lib/parser.c: put EXPORT_SYMBOLs in the conventional place

2014-01-23 16:36:55 -08:00

pci_iomap.c

libnvdimm for 4.3:

2015-09-08 14:35:59 -07:00

percpu_counter.c

percpu_counter: update debugobjects fixup callbacks return type

2016-05-19 19:12:14 -07:00

percpu_ida.c

mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM

2015-11-06 17:50:42 -08:00

percpu_test.c

percpu: add test module for various percpu operations

2013-11-13 12:09:11 +09:00

percpu-refcount.c

percpu-refcount: init ->confirm_switch member properly

2016-08-11 13:52:23 -04:00

plist.c

lib/plist.c: remove redundant include

2015-02-12 18:54:16 -08:00

pm-notifier-error-inject.c

…

radix-tree.c

Revert "radix tree test suite: fix compilation"

2016-12-09 10:41:42 -08:00

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

lib/ratelimit.c: use deferred printk() version

2017-10-12 11:51:19 +02:00

rational.c

…

rbtree_test.c

rbtree/test: test rbtree_postorder_for_each_entry_safe()

2014-01-23 16:37:03 -08:00

rbtree.c

Introduce rb_replace_node_rcu()

2016-07-06 10:51:14 +01:00

reciprocal_div.c

reciprocal_divide: update/correction of the algorithm

2014-01-21 23:17:20 -08:00

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

scatterlist: fix a typo in comment block of sg_miter_stop()

2016-02-08 10:15:17 -08:00

seq_buf.c

tracing: Use seq_buf_used() in seq_buf_to_user() instead of len

2015-12-23 14:27:20 -05:00

sg_pool.c

lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.c

2016-04-15 16:53:14 -04:00

sg_split.c

lib: scatterlist: add sg splitting function

2015-08-24 14:28:01 -06:00

sha1.c

lib: EXPORT_SYMBOL sha_init

2015-03-23 22:12:08 -04:00

show_mem.c

lib/show_mem.c: correct reserved memory calculation

2015-09-08 15:35:28 -07:00

smp_processor_id.c

percpu: add preemption checks to __this_cpu ops

2014-04-07 16:36:14 -07:00

sort.c

lib/sort: Add 64 bit swap function

2015-06-25 17:00:40 -07:00

stackdepot.c

lib/stackdepot: export save/fetch stack for drivers

2016-11-11 08:12:37 -08:00

stmp_device.c

lib/stmp_device.c: replace module.h include

2015-02-12 18:54:16 -08:00

string_helpers.c

string_helpers: add kstrdup_quotable_file

2016-04-21 10:47:26 +10:00

string.c

lib: move strtobool() to kstrtobool()

2016-03-17 15:09:34 -07:00

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

swiotlb: ensure that page-sized mappings are page-aligned

2017-07-05 14:40:26 +02:00

syscall.c

lib/syscall: Clear return values when no stack

2017-04-08 09:30:35 +02:00

test_bitmap.c

test_bitmap: unit tests for lib/bitmap.c

2016-02-19 22:54:09 -05:00

test_bpf.c

bpf, arm64: fix jit branch offset related to ldimm64

2017-05-14 14:00:21 +02:00

test_firmware.c

test: firmware_class: add asynchronous request trigger

2016-01-07 13:44:22 -07:00

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_hexdump: print statistics at the end

2016-01-20 17:09:18 -08:00

test_kasan.c

kasan: support use-after-scope detection

2016-11-30 16:32:52 -08:00

test_module.c

test: add minimal module for verification testing

2014-01-23 16:36:57 -08:00

test_printf.c

mm, printk: introduce new format string for flags

2016-03-15 16:55:16 -07:00

test_rhashtable.c

rhashtable-test: Fix max_size parameter description

2016-08-08 12:52:42 -07:00

test_static_key_base.c

locking/static_keys: Provide a selftest

2015-08-03 11:51:12 +02:00

test_static_keys.c

locking/static_keys: Avoid nested functions

2016-02-09 10:27:29 +01:00

test_user_copy.c

usercopy: Adjust tests to deal with SMAP/PAN

2017-06-14 15:06:05 +02:00

test_uuid.c

lib/uuid: add a test module

2016-05-30 15:26:57 -07:00

test-kstrtox.c

kstrto*: accept "-0" for signed conversion

2015-09-10 13:29:01 -07:00

test-string_helpers.c

lib/test-string_helpers.c: fix and improve string_get_size() tests

2016-02-03 08:28:43 -08:00

textsearch.c

lib/textsearch.c: remove textsearch_put reference from comments

2014-10-14 02:18:14 +02:00

timerqueue.c

timerqueue: Let timerqueue_add/del return information

2015-04-22 17:06:49 +02:00

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

UBSAN: run-time undefined behavior sanity checker

2016-01-20 17:09:18 -08:00

ucs2_string.c

lib/ucs2_string: Speed up ucs2_utf8size()

2016-09-09 16:08:46 +01:00

uuid.c

lib/uuid.c: use correct offset in uuid parser

2016-05-30 15:26:57 -07:00

vsprintf.c

lib/uuid.c: introduce a few more generic helpers

2016-05-20 17:58:30 -07:00

win_minmax.c

lib/win_minmax: windowed min or max estimator

2016-09-21 00:22:59 -04:00