Daniel Xu 6fa6d28051 lib/strncpy_from_user.c: Mask out bytes after NUL terminator. ... do_strncpy_from_user() may copy some extra bytes after the NUL terminator into the destination buffer. This usually does not matter for normal string operations. However, when BPF programs key BPF maps with strings, this matters a lot. A BPF program may read strings from user memory by calling the bpf_probe_read_user_str() helper which eventually calls do_strncpy_from_user(). The program can then key a map with the destination buffer. BPF map keys are fixed-width and string-agnostic, meaning that map keys are treated as a set of bytes. The issue is when do_strncpy_from_user() overcopies bytes after the NUL terminator, it can result in seemingly identical strings occupying multiple slots in a BPF map. This behavior is subtle and totally unexpected by the user. This commit masks out the bytes following the NUL while preserving long-sized stride in the fast path. Fixes: 6ae08ae3de ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers") Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz		2020-11-19 11:56:16 -08:00
..
842
crypto	crypto: lib/chacha20poly1305 - Set SG_MITER_ATOMIC unconditionally	2020-09-25 17:48:13 +10:00
dim
fonts	Fonts: Replace discarded const qualifier	2020-11-03 10:51:34 +01:00
kunit	linux-kselftest-kunit-5.10-rc1	2020-10-18 14:45:59 -07:00
livepatch
lz4
lzo
math	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
mpi	lib/mpi/mpi-bit.c: fix spello of "functions"	2020-10-16 11:11:20 -07:00
pldmfw
raid6
reed_solomon
vdso
xz
zlib_deflate
zlib_dfltcc
zlib_inflate
zstd
.gitignore
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
assoc_array.c
atomic64_test.c
atomic64.c
audit.c
bcd.c
bch.c
bitfield_kunit.c	lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE	2020-10-16 13:25:14 -06:00
bitmap.c	lib: bitmap: delete duplicated words	2020-10-16 11:11:19 -07:00
bitrev.c
bootconfig.c	lib/bootconfig: Fix to remove tailing spaces after value	2020-09-21 21:50:09 -04:00
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
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c	lib/crc32.c: fix trivial typo in preprocessor condition	2020-10-16 11:11:20 -07:00
crc32defs.h
crc32test.c	lib/crc32test: remove extra local_irq_disable/enable	2020-11-02 12:14:19 -08:00
crc64.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c	debugobjects: Free per CPU pool after CPU unplug	2020-10-01 16:13:54 +02:00
dec_and_lock.c
decompress_bunzip2.c	lib: decompress_bunzip2: delete duplicated words	2020-10-16 11:11:19 -07:00
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress_unzstd.c
decompress.c
devres.c
digsig.c
dump_stack.c
dynamic_debug.c	dyndbg: use keyword, arg varnames for query term pairs	2020-09-27 14:32:09 +02:00
dynamic_queue_limits.c	lib: dynamic_queue_limits: delete duplicated words + fix typo	2020-10-16 11:11:20 -07:00
earlycpio.c	lib: earlycpio: delete duplicated words	2020-10-16 11:11:20 -07:00
errname.c
error-inject.c
errseq.c
extable.c
fault-inject-usercopy.c	lib, include/linux: add usercopy failure capability	2020-10-16 11:11:22 -07:00
fault-inject.c
fdt_addresses.c
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	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
flex_proportions.c
gen_crc32table.c
gen_crc64table.c
genalloc.c
generic-radix-tree.c
glob.c
globtest.c
hexdump.c	kernel.h: split out min()/max() et al. helpers	2020-10-16 11:11:19 -07:00
hweight.c
idr.c	XArray updates for 5.9	2020-10-20 14:39:37 -07:00
inflate.c
interval_tree_test.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
iov_iter.c	lib, uaccess: add failure injection to usercopy functions	2020-10-16 11:11:22 -07:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c
Kconfig	x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()	2020-10-06 11:18:04 +02:00
Kconfig.debug	docs: Kconfig/Makefile: add a check for broken ABI files	2020-10-30 13:08:07 +01:00
Kconfig.kasan	KASAN: port KASAN Tests to KUnit	2020-10-13 18:38:32 -07:00
Kconfig.kcsan
Kconfig.kgdb	kgdb: Honour the kprobe blocklist when setting breakpoints	2020-09-28 12:14:08 +01:00
Kconfig.ubsan	ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang	2020-10-16 11:11:22 -07:00
kfifo.c
klist.c
kobject_uevent.c
kobject.c
kstrtox.c
kstrtox.h
libcrc32c.c	lib: libcrc32c: delete duplicated words	2020-10-16 11:11:19 -07:00
linear_ranges.c
list_debug.c
list_sort.c
list-test.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-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	linux-kselftest-kunit-5.10-rc1	2020-10-18 14:45:59 -07:00
memcat_p.c
memory-notifier-error-inject.c
memregion.c	lib/memregion.c: include memregion.h	2020-09-26 10:33:57 -07:00
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c	netlink: export policy in extended ACK	2020-10-09 20:22:32 -07:00
nmi_backtrace.c
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
packing.c
parman.c
parser.c
pci_iomap.c
percpu_counter.c	lib/percpu_counter.c: use helper macro abs()	2020-10-16 11:11:20 -07:00
percpu_test.c
percpu-refcount.c	percpu_ref: don't refer to ref->data if it isn't allocated	2020-10-09 12:32:06 -06:00
plist.c
pm-notifier-error-inject.c
radix-tree.c	XArray updates for 5.9	2020-10-20 14:39:37 -07:00
random32.c	random32: add a selftest for the prandom32 code	2020-10-24 20:21:57 +02:00
ratelimit.c
rbtree_test.c
rbtree.c
refcount.c
rhashtable.c
sbitmap.c
scatterlist.c	lib/scatterlist: use consistent sg_copy_buffer() return type	2020-10-29 08:55:45 -06:00
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
show_mem.c
siphash.c
smp_processor_id.c
sort.c
stackdepot.c
stmp_device.c
string_helpers.c	lib: string_helpers: provide kfree_strarray()	2020-09-30 10:50:30 +02:00
string.c	lib/string.c: implement stpcpy	2020-09-26 10:33:57 -07:00
strncpy_from_user.c	lib/strncpy_from_user.c: Mask out bytes after NUL terminator.	2020-11-19 11:56:16 -08:00
strnlen_user.c
syscall.c	lib: syscall: delete duplicated words	2020-10-16 11:11:20 -07:00
test_bitmap.c
test_bitops.c
test_bits.c
test_blackhole_dev.c
test_bpf.c
test_debug_virtual.c
test_firmware.c	test_firmware: Test partial read support	2020-10-05 13:37:04 +02:00
test_fpu.c
test_free_pages.c	mm/page_alloc.c: fix freeing non-compound pages	2020-10-13 18:38:33 -07:00
test_hash.c
test_hexdump.c
test_hmm_uapi.h
test_hmm.c	lib/test_hmm.c: fix an error code in dmirror_allocate_chunk()	2020-10-16 11:11:20 -07:00
test_ida.c
test_kasan_module.c	KASAN: port KASAN Tests to KUnit	2020-10-13 18:38:32 -07:00
test_kasan.c	kasan: adopt KUNIT tests to SW_TAGS mode	2020-11-02 12:14:18 -08:00
test_kmod.c
test_linear_ranges.c
test_list_sort.c
test_lockup.c
test_memcat_p.c
test_meminit.c
test_min_heap.c
test_module.c
test_objagg.c
test_overflow.c
test_parman.c
test_printf.c
test_rhashtable.c
test_siphash.c
test_sort.c
test_stackinit.c
test_static_key_base.c
test_static_keys.c
test_string.c
test_strscpy.c
test_sysctl.c	lib: test_sysctl: delete duplicated words	2020-10-16 11:11:20 -07:00
test_ubsan.c
test_user_copy.c
test_uuid.c
test_vmalloc.c
test_xarray.c	XArray updates for 5.9	2020-10-20 14:39:37 -07:00
test-kstrtox.c
test-string_helpers.c
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c
ubsan.h
ucmpdi2.c
ucs2_string.c
usercopy.c	lib, uaccess: add failure injection to usercopy functions	2020-10-16 11:11:22 -07:00
uuid.c
vsprintf.c	vsprintf: use bd_partno in bdev_name	2020-09-25 08:18:58 -06:00
win_minmax.c
xarray.c	XArray updates for 5.9	2020-10-20 14:39:37 -07:00
xxhash.c