Ilya Dryomov 7bd57fbc4a vsprintf: don't obfuscate NULL and error pointers ... I don't see what security concern is addressed by obfuscating NULL and IS_ERR() error pointers, printed with %p/%pK. Given the number of sites where %p is used (over 10000) and the fact that NULL pointers aren't uncommon, it probably wouldn't take long for an attacker to find the hash that corresponds to 0. Although harder, the same goes for most common error values, such as -1, -2, -11, -14, etc. The NULL part actually fixes a regression: NULL pointers weren't obfuscated until commit 3e5903eb9c ("vsprintf: Prevent crash when dereferencing invalid pointers") which went into 5.2. I'm tacking the IS_ERR() part on here because error pointers won't leak kernel addresses and printing them as pointers shouldn't be any different from e.g. %d with PTR_ERR_OR_ZERO(). Obfuscating them just makes debugging based on existing pr_debug and friends excruciating. Note that the "always print 0's for %pK when kptr_restrict == 2" behaviour which goes way back is left as is. Example output with the patch applied: ptr error-ptr NULL %p: 0000000001f8cc5b fffffffffffffff2 0000000000000000 %pK, kptr = 0: 0000000001f8cc5b fffffffffffffff2 0000000000000000 %px: ffff888048c04020 fffffffffffffff2 0000000000000000 %pK, kptr = 1: ffff888048c04020 fffffffffffffff2 0000000000000000 %pK, kptr = 2: 0000000000000000 0000000000000000 0000000000000000 Fixes: 3e5903eb9c ("vsprintf: Prevent crash when dereferencing invalid pointers") Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-05-19 11:35:38 -07:00
..
842
crypto	crypto: arm64/chacha - correctly walk through blocks	2020-03-20 14:35:27 +11:00
dim
fonts
kunit	kunit: Add missing newline in summary message	2020-04-23 15:42:00 -06:00
livepatch	livepatch/samples/selftest: Use klp_shadow_alloc() API correctly	2020-01-17 11:12:06 +01:00
lz4
lzo
math	lib/math/rational.c: fix possible incorrect result from rational fractions helper	2019-12-04 19:44:13 -08:00
mpi	lib/mpi: Fix building for powerpc with clang	2020-04-24 13:14:59 +10:00
raid6	x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2	2020-04-09 00:12:48 +09:00
reed_solomon
vdso	lib/vdso: Enable common headers	2020-03-21 15:24:03 +01:00
xz
zlib_deflate	lib/zlib: add zlib_deflate_dfltcc_enabled() function	2020-01-31 10:30:40 -08:00
zlib_dfltcc	lib/zlib: add zlib_deflate_dfltcc_enabled() function	2020-01-31 10:30:40 -08:00
zlib_inflate	lib/zlib: add s390 hardware support for kernel zlib_inflate	2020-01-31 10:30:40 -08:00
zstd
.gitignore	.gitignore: add SPDX License Identifier	2020-03-25 11:50:48 +01:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
assoc_array.c
atomic64_test.c
atomic64.c
audit.c
bcd.c
bch.c	lib/bch.c: replace zero-length array with flexible-array member	2020-04-07 10:43:42 -07:00
bitmap.c	lib: rework bitmap_parse()	2020-02-04 03:05:26 +00:00
bitrev.c
bootconfig.c	tools/bootconfig: Show line and column in parse error	2020-03-03 17:38:42 -05:00
bsearch.c
btree.c
bucket_locks.c
bug.c
build_OID_registry
bust_spinlocks.c
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask.c	sched/core: Distribute tasks within affinity masks	2020-03-20 13:06:18 +01:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc64.c	lib: crc64: include <linux/crc64.h> for 'crc64_be'	2020-01-23 11:40:01 -07:00
ctype.c
debug_info.c
debug_locks.c
debugobjects.c	debugobjects: Fix various data races	2020-01-17 15:45:01 +01:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c	lib/zlib: add s390 hardware support for kernel zlib_inflate	2020-01-31 10:30:40 -08:00
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
devres.c	remove ioremap_nocache and devm_ioremap_nocache	2020-01-06 09:45:59 +01:00
digsig.c
dump_stack.c
dynamic_debug.c	lib/dynamic_debug.c: use address-of operator on section symbols	2020-04-07 10:43:43 -07:00
dynamic_queue_limits.c
earlycpio.c
errname.c
error-inject.c
errseq.c
extable.c
fault-inject.c
fdt_addresses.c	libfdt: include fdt_addresses.c	2020-01-08 16:59:19 +00:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit_benchmark.c
find_bit.c	lib/find_bit.c: uninline helper _find_next_bit()	2020-01-31 10:30:41 -08:00
flex_proportions.c
gen_crc32table.c
gen_crc64table.c
genalloc.c	lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr	2019-12-04 19:44:13 -08:00
generic-radix-tree.c
glob.c
globtest.c
hexdump.c
hweight.c
idr.c
inflate.c
interval_tree_test.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
ioremap.c
iov_iter.c	pipe: Fix bogus dereference in iov_iter_alignment()	2019-12-16 12:48:10 -05:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c
Kconfig	mm/memremap_pages: Introduce memremap_compat_align()	2020-02-20 16:58:55 -08:00
Kconfig.debug	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf	2020-04-09 17:39:22 -07:00
Kconfig.kasan	kasan: support backing vmalloc space with real shadow memory	2019-12-01 12:59:05 -08:00
Kconfig.kgdb	lib/: fix Kconfig indentation	2019-12-07 11:00:19 -08:00
Kconfig.ubsan	ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST	2020-05-07 19:27:21 -07:00
kfifo.c
klist.c
kobject_uevent.c
kobject.c
kstrtox.c
kstrtox.h
libcrc32c.c
list_debug.c
list_sort.c
list-test.c	Fix linked-list KUnit test when run multiple times	2020-03-25 16:38:39 -06:00
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-rtmutex.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
logic_pio.c
lru_cache.c
lshrdi3.c
Makefile	ubsan: add trap instrumentation option	2020-04-07 10:43:44 -07:00
memcat_p.c
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c	lib: objagg: Replace zero-length arrays with flexible-array member	2020-02-16 18:33:00 -08:00
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
packing.c
parman.c
parser.c
pci_iomap.c
percpu_counter.c
percpu_test.c
percpu-refcount.c	percpu_ref: Fix comment regarding percpu_ref_init flags	2020-03-05 13:10:26 -08:00
plist.c
pm-notifier-error-inject.c
radix-tree.c	ida: remove abandoned macros	2020-01-31 15:09:49 -05:00
random32.c
ratelimit.c
rbtree_test.c
rbtree.c	lib/rbtree: fix coding style of assignments	2020-04-07 10:43:43 -07:00
refcount.c
rhashtable.c
sbitmap.c	sbitmap: only queue kyber's wait callback if not already active	2019-12-20 16:51:54 -07:00
scatterlist.c	lib/scatterlist: fix sg_copy_buffer() kerneldoc	2020-04-07 10:43:43 -07:00
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
show_mem.c
siphash.c
smp_processor_id.c
sort.c
stackdepot.c	kasan: stackdepot: move filter_irq_stacks() to stackdepot.c	2020-04-07 10:43:43 -07:00
stmp_device.c
string_helpers.c
string.c	lib/string.c: update match_string() doc-strings with correct behavior	2020-02-21 11:22:15 -08:00
strncpy_from_user.c	lib: Reduce user_access_begin() boundaries in strncpy_from_user() and strnlen_user()	2020-01-24 09:27:34 -08:00
strnlen_user.c	lib: Reduce user_access_begin() boundaries in strncpy_from_user() and strnlen_user()	2020-01-24 09:27:34 -08:00
syscall.c
test_bitfield.c
test_bitmap.c	lib/test_bitmap.c: make use of EXP2_IN_BITS	2020-04-07 10:43:43 -07:00
test_blackhole_dev.c
test_bpf.c	bpf/tests: Use migrate disable instead of preempt disable	2020-02-24 16:20:09 -08:00
test_debug_virtual.c
test_firmware.c	test_firmware: add support for firmware_request_platform	2020-03-20 14:54:04 +01:00
test_hash.c
test_hexdump.c
test_ida.c
test_kasan.c	kasan: add test for invalid size in memmove	2020-04-02 09:35:30 -07:00
test_kmod.c	lib/test_kmod.c: remove a NULL test	2020-04-07 10:43:43 -07:00
test_list_sort.c
test_lockup.c	lib/test_lockup.c: add parameters for locking generic vfs locks	2020-04-07 10:43:42 -07:00
test_memcat_p.c
test_meminit.c	lib/test_meminit.c: add bulk alloc/free tests	2019-12-04 19:44:13 -08:00
test_min_heap.c	lib: Introduce generic min-heap	2020-03-06 11:56:59 +01:00
test_module.c
test_objagg.c
test_overflow.c
test_parman.c
test_printf.c	vsprintf: don't obfuscate NULL and error pointers	2020-05-19 11:35:38 -07:00
test_rhashtable.c
test_siphash.c
test_sort.c
test_stackinit.c	lib: test_stackinit.c: XFAIL switch variable init tests	2020-04-07 10:43:43 -07:00
test_static_key_base.c
test_static_keys.c
test_string.c
test_strscpy.c
test_sysctl.c
test_ubsan.c
test_user_copy.c
test_uuid.c
test_vmalloc.c
test_xarray.c	XArray: Fix xas_pause for large multi-index entries	2020-01-31 15:09:49 -05:00
test-kstrtox.c
test-string_helpers.c
textsearch.c
timerqueue.c
ts_bm.c	lib/ts_bm.c: replace zero-length array with flexible-array member	2020-04-07 10:43:42 -07:00
ts_fsm.c	lib/ts_fsm.c: replace zero-length array with flexible-array member	2020-04-07 10:43:43 -07:00
ts_kmp.c	lib/ts_kmp.c: replace zero-length array with flexible-array member	2020-04-07 10:43:43 -07:00
ubsan.c	ubsan: include bug type in report header	2020-04-07 10:43:44 -07:00
ubsan.h
ucmpdi2.c
ucs2_string.c
usercopy.c
uuid.c	uuid: Provide a GUID generator for raw buffer	2020-03-23 17:01:47 +01:00
vsprintf.c	vsprintf: don't obfuscate NULL and error pointers	2020-05-19 11:35:38 -07:00
win_minmax.c
xarray.c	xarray: Fix early termination of xas_for_each_marked	2020-03-12 17:42:08 -04:00
xxhash.c