linux-stable/lib
Linus Torvalds fb5e51c0aa iov_iter: fix build issue due to possible type mis-match
commit 1c27f1fc15 upstream.

Commit 6c77676645 ("iov_iter: Fix iter_xarray_get_pages{,_alloc}()")
introduced a problem on some 32-bit architectures (at least arm, xtensa,
csky,sparc and mips), that have a 'size_t' that is 'unsigned int'.

The reason is that we now do

    min(nr * PAGE_SIZE - offset, maxsize);

where 'nr' and 'offset' and both 'unsigned int', and PAGE_SIZE is
'unsigned long'.  As a result, the normal C type rules means that the
first argument to 'min()' ends up being 'unsigned long'.

In contrast, 'maxsize' is of type 'size_t'.

Now, 'size_t' and 'unsigned long' are always the same physical type in
the kernel, so you'd think this doesn't matter, and from an actual
arithmetic standpoint it doesn't.

But on 32-bit architectures 'size_t' is commonly 'unsigned int', even if
it could also be 'unsigned long'.  In that situation, both are unsigned
32-bit types, but they are not the *same* type.

And as a result 'min()' will complain about the distinct types (ignore
the "pointer types" part of the error message: that's an artifact of the
way we have made 'min()' check types for being the same):

  lib/iov_iter.c: In function 'iter_xarray_get_pages':
  include/linux/minmax.h:20:35: error: comparison of distinct pointer types lacks a cast [-Werror]
     20 |         (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
        |                                   ^~
  lib/iov_iter.c:1464:16: note: in expansion of macro 'min'
   1464 |         return min(nr * PAGE_SIZE - offset, maxsize);
        |                ^~~

This was not visible on 64-bit architectures (where we always define
'size_t' to be 'unsigned long').

Force these cases to use 'min_t(size_t, x, y)' to make the type explicit
and avoid the issue.

[ Nit-picky note: technically 'size_t' doesn't have to match 'unsigned
  long' arithmetically. We've certainly historically seen environments
  with 16-bit address spaces and 32-bit 'unsigned long'.

  Similarly, even in 64-bit modern environments, 'size_t' could be its
  own type distinct from 'unsigned long', even if it were arithmetically
  identical.

  So the above type commentary is only really descriptive of the kernel
  environment, not some kind of universal truth for the kinds of wild
  and crazy situations that are allowed by the C standard ]

Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/all/YqRyL2sIqQNDfky2@debian/
Cc: Jeff Layton <jlayton@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:36:28 +02:00
..
842 kbuild: trace functions in subdirectories of lib/ 2020-08-10 01:32:59 +09:00
crypto lib/crypto: add prompts back to crypto libraries 2022-06-06 08:43:37 +02:00
dim dim: initialize all struct fields 2022-05-18 10:26:49 +02:00
fonts lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
kunit kunit: fix debugfs code to use enum kunit_status, not bool 2022-06-09 10:22:53 +02:00
livepatch Kbuild updates for v5.9 2020-08-09 14:10:26 -07:00
lz4 lz4: fix LZ4_decompress_safe_partial read out of bound 2022-04-13 20:59:21 +02:00
lzo lib/lzo/lzo1x_compress.c: make lzogeneric1x_1_compress() static 2020-12-15 22:46:19 -08:00
math math: make RATIONAL tristate 2021-09-08 11:50:26 -07:00
mpi lib/mpi: Add the return value check of kcalloc() 2022-01-27 11:03:58 +01:00
pldmfw lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
raid6 lib/raid6/test/Makefile: Use $(pound) instead of \# for Make 4.3 2022-04-08 14:23:56 +02:00
reed_solomon lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
vdso lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data() 2021-04-14 23:04:44 +10:00
xz lib/xz: Validate the value before assigning it to an enum variable 2021-11-18 19:16:17 +01:00
zlib_deflate kbuild: trace functions in subdirectories of lib/ 2020-08-10 01:32:59 +09:00
zlib_dfltcc zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c 2020-12-29 15:36:49 -08:00
zlib_inflate lib/zlib_inflate/inffast: check config in C to avoid unused function warning 2021-09-24 16:13:35 -07:00
zstd lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
asn1_encoder.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
assoc_array.c assoc_array: Fix BUG_ON during garbage collect 2022-06-06 08:43:37 +02:00
atomic64.c locking/atomic: atomic64: support ARCH_ATOMIC 2021-05-26 13:20:50 +02:00
atomic64_test.c
audit.c
bcd.c
bch.c lib/bch.c: fix a typo in the file bch.c 2021-05-06 19:24:12 -07:00
bitfield_kunit.c lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE 2020-10-16 13:25:14 -06:00
bitmap.c bitmap: extend comment to bitmap_print_bitmask/list_to_buf 2021-08-13 10:27:50 +02:00
bitrev.c
bootconfig.c memblock: introduce saner 'memblock_free_ptr()' interface 2021-09-14 13:23:22 -07:00
bsearch.c lib/bsearch: Provide __always_inline variant 2020-06-11 15:14:53 +02:00
btree.c
bucket_locks.c
bug.c bug: Assign values once in bug_get_file_line() 2021-04-01 09:54:37 +01:00
build_OID_registry
buildid.c kdump: use vmlinux_build_id to simplify 2021-07-08 11:48:22 -07:00
bust_spinlocks.c
check_signature.c
checksum.c unify generic instances of csum_partial_copy_nocheck() 2020-08-20 15:45:14 -04:00
clz_ctz.c
clz_tab.c
cmdline.c lib/cmdline: Export next_arg() for being used in modules 2021-05-05 16:07:40 +02:00
cmdline_kunit.c lib/cmdline_kunit: Remove a cast which are no-longer required 2021-06-23 16:41:41 -06:00
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask.c Revert "lib: Restrict cpumask_local_spread to houskeeping CPUs" 2021-02-05 23:28:29 +01:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c crc-t10dif: clean up some more things 2020-06-18 17:26:43 +10:00
crc4.c
crc7.c lib/crc7: fix a kernel-doc markup 2021-01-21 14:06:00 -07:00
crc8.c lib: crc8: pointer to data block should be const 2021-05-06 19:24:12 -07:00
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 lib: crc64: fix kernel-doc warning 2021-06-05 08:58:12 -07:00
ctype.c
debug_info.c isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
debug_locks.c locking/lockdep: Improve noinstr vs errors 2021-06-22 13:56:43 +02:00
debugobjects.c debugobjects: Make them PREEMPT_RT aware 2021-08-13 10:07:44 +02:00
dec_and_lock.c
decompress.c lib: Add zstd support to decompress 2020-07-31 11:49:08 +02:00
decompress_bunzip2.c lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
decompress_inflate.c lib/zlib: add s390 hardware support for kernel zlib_inflate 2020-01-31 10:30:40 -08:00
decompress_unlz4.c lib/decompress_unlz4.c: correctly handle zero-padding around initrds. 2021-07-01 11:06:06 -07:00
decompress_unlzma.c lib: fix inconsistent indenting in process_bit1() 2021-05-06 19:24:12 -07:00
decompress_unlzo.c lib/decompressors: remove set but not used variabled 'level' 2021-07-01 11:06:06 -07:00
decompress_unxz.c lib/xz: Avoid overlapping memcpy() with invalid input with in-place decompression 2021-11-18 19:16:17 +01:00
decompress_unzstd.c lib/decompressors: fix spelling mistakes 2021-07-01 11:06:05 -07:00
devmem_is_allowed.c lib: use PFN_PHYS() in devmem_is_allowed() 2021-08-13 14:09:32 -10:00
devres.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
digsig.c crypto: sha - split sha.h into sha1.h and sha2.h 2020-11-20 14:45:33 +11:00
dump_stack.c lib/dump_stack: correct kernel-doc notation 2021-09-08 11:50:26 -07:00
dynamic_debug.c dyndbg: make dyndbg a known cli param 2021-11-18 19:16:52 +01:00
dynamic_queue_limits.c lib: dynamic_queue_limits: delete duplicated words + fix typo 2020-10-16 11:11:20 -07:00
earlycpio.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
errname.c kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
error-inject.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
errseq.c kernel.h: split out mathematical helpers 2020-12-15 22:46:15 -08:00
extable.c sparc32: switch to generic extables 2021-01-03 20:05:18 -05:00
fault-inject-usercopy.c lib, include/linux: add usercopy failure capability 2020-10-16 11:11:22 -07:00
fault-inject.c fault_inject: Don't rely on "return value" from WRITE_ONCE() 2020-04-15 21:36:41 +01:00
fdt.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
find_bit.c lib: add fast path for find_first_*_bit() and find_last_bit() 2021-05-06 19:24:12 -07:00
find_bit_benchmark.c
flex_proportions.c lib/flex_proportions.c: cleanup __fprop_inc_percpu_max 2020-06-04 19:06:25 -07:00
gen_crc32table.c
gen_crc64table.c
genalloc.c lib/genalloc: add parameter description to fix doc compile warning 2021-05-06 19:24:12 -07:00
generic-radix-tree.c
glob.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
globtest.c
hexdump.c hex2bin: fix access beyond string end 2022-05-09 09:14:30 +02:00
hweight.c
idr.c XArray updates for 5.9 2020-10-20 14:39:37 -07:00
inflate.c
interval_tree.c
interval_tree_test.c
iomap.c iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
iomap_copy.c
iommu-helper.c
iov_iter.c iov_iter: fix build issue due to possible type mis-match 2022-06-14 18:36:28 +02:00
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
Kconfig lib/crypto: add prompts back to crypto libraries 2022-06-06 08:43:37 +02:00
Kconfig.debug random: remove ratelimiting for in-kernel unseeded randomness 2022-05-30 09:29:16 +02:00
Kconfig.kasan kasan: fix Kconfig check of CC_HAS_WORKING_NOSANITIZE_ADDRESS 2021-09-24 16:13:34 -07:00
Kconfig.kcsan kcsan: Make strict mode imply interruptible watchers 2021-07-20 13:49:44 -07:00
Kconfig.kfence kfence: default to dynamic branch instead of static keys mode 2021-11-12 15:05:49 +01:00
Kconfig.kgdb kgdb: Honour the kprobe blocklist when setting breakpoints 2020-09-28 12:14:08 +01:00
Kconfig.ubsan ubsan: remove CONFIG_UBSAN_OBJECT_SIZE 2022-04-13 20:59:27 +02:00
kfifo.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
klist.c
kobject.c kobject: Drop unneeded conditional in __kobject_del() 2020-09-07 11:24:17 +02:00
kobject_uevent.c kobject_uevent: remove warning in init_uevent_argv() 2021-04-10 11:09:41 +02:00
kstrtox.c Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
kstrtox.h lib: vsprintf: Fix handling of number field widths in vsscanf 2021-05-19 15:05:11 +02:00
libcrc32c.c lib: libcrc32c: delete duplicated words 2020-10-16 11:11:19 -07:00
linear_ranges.c lib: add linear range get selector within 2021-08-13 18:37:38 +02:00
list-test.c list: test: Add a test for list_is_head() 2022-06-09 10:23:31 +02:00
list_debug.c
list_sort.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
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 lockdep/selftest: Remove wait-type RCU_CALLBACK tests 2021-06-22 16:42:08 +02:00
lockref.c
logic_iomem.c lib/logic_iomem: correct fallback config references 2022-04-13 20:58:59 +02:00
logic_pio.c PCI: Fix pci_register_io_range() memory leak 2021-02-17 17:31:06 -06:00
lru_cache.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
lshrdi3.c
Makefile bootconfig: Make the bootconfig.o as a normal object file 2022-06-14 18:36:14 +02:00
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 lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
nmi_backtrace.c printk: restore flushing of NMI buffers on remote CPUs after NMI backtraces 2021-11-25 09:48:45 +01:00
nodemask.c nodemask: Fix return values to be unsigned 2022-06-14 18:36:24 +02:00
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 lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
once.c once: Fix panic when module unload 2021-08-08 13:00:20 +01:00
packing.c net: update NXP copyright text 2021-09-17 13:52:17 +01:00
parman.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
parser.c kernel.h: split out kstrtox() and simple_strtox() to a separate header 2021-07-01 11:06:05 -07:00
pci_iomap.c pci_iounmap'2: Electric Boogaloo: try to make sense of it all 2021-09-19 17:13:35 -07:00
percpu-refcount.c percpu_ref_init(): clean ->percpu_count_ref on failure 2022-06-06 08:43:36 +02:00
percpu_counter.c lib/percpu_counter: tame kernel-doc compile warning 2021-05-06 19:24:12 -07:00
percpu_test.c
plist.c
pm-notifier-error-inject.c
radix-tree.c lib: remove "expecting prototype" kernel-doc warnings 2021-04-16 16:10:37 -07:00
random32.c random: replace custom notifier chain with standard one 2022-05-30 09:29:10 +02:00
ratelimit.c
rbtree.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
rbtree_test.c
refcount.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
rhashtable.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
sbitmap.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
scatterlist.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
seq_buf.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
sg_pool.c lib/scatterlist: Fix wrong update of orig_nents 2021-08-24 19:52:40 -03:00
sg_split.c
sha1.c lib/crypto: sha1: re-roll loops to reduce code size 2022-05-30 09:28:59 +02:00
show_mem.c
siphash.c siphash: use one source of truth for siphash permutations 2022-05-30 09:29:15 +02:00
slub_kunit.c mm/slub, kunit: add a KUnit test for SLUB debugging functionality 2021-06-29 10:53:46 -07:00
smp_processor_id.c lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed 2021-05-19 10:51:40 +02:00
sort.c lib: fix spelling mistakes 2021-07-08 11:48:20 -07:00
stackdepot.c stacktrace: move filter_irq_stacks() to kernel/stacktrace.c 2022-04-13 20:59:28 +02:00
stmp_device.c
string.c string: improve default out-of-line memcmp() implementation 2021-08-30 07:50:56 -07:00
string_helpers.c string: uninline memcpy_and_pad 2021-11-21 13:44:12 +01:00
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 uaccess: Selectively open read or write user access 2020-05-01 12:35:21 +10:00
syscall.c sched: Change task_struct::state 2021-06-18 11:43:09 +02:00
test-kstrtox.c
test-string_helpers.c string_helpers: Escape double quotes in escape_special 2021-07-19 11:39:28 +02:00
test_bitmap.c lib: test_bitmap: add bitmap_print_bitmask/list_to_buf test cases 2021-08-13 10:27:49 +02:00
test_bitops.c lib/test: fix spelling mistakes 2021-07-08 11:48:20 -07:00
test_bits.c lib/test_bits.c: add tests of GENMASK 2020-08-12 10:58:00 -07:00
test_blackhole_dev.c
test_bpf.c bpf/tests: Fix error in tail call limit tests 2021-11-18 19:16:26 +01:00
test_debug_virtual.c
test_firmware.c firmware: replace HOTPLUG with UEVENT in FW_ACTION defines 2021-05-13 16:14:45 +02:00
test_fpu.c selftests/fpu: Fix debugfs_simple_attr.cocci warning 2021-01-18 11:03:26 +01:00
test_free_pages.c lib/test_free_pages.c: add basic progress indicators 2020-12-15 22:46:16 -08:00
test_hash.c
test_hexdump.c
test_hmm.c mm/hmm.c: allow VM_MIXEDMAP to work with hmm_range_fault 2022-01-27 11:05:43 +01:00
test_hmm_uapi.h mm: selftests for exclusive device memory 2021-07-01 11:06:03 -07:00
test_ida.c
test_kasan.c Merge branch 'akpm' (patches from Andrew) 2021-09-03 10:08:28 -07:00
test_kasan_module.c kasan: test: avoid corrupting memory in kasan_rcu_uaf 2021-09-03 09:58:15 -07:00
test_kmod.c lib/test: use after free in register_test_dev_kmod() 2022-04-08 14:23:54 +02:00
test_linear_ranges.c lib/test_linear_ranges: add a test for the 'linear_ranges' 2020-05-08 18:18:12 +01:00
test_list_sort.c lib/test: convert lib/test_list_sort.c to use KUnit 2021-06-25 11:31:03 -06:00
test_lockup.c lib/test_lockup: fix kernel pointer check for separate address spaces 2022-04-08 14:24:01 +02:00
test_memcat_p.c
test_meminit.c lib/test_meminit: destroy cache in kmem_cache_alloc_bulk() test 2022-01-27 11:05:44 +01:00
test_min_heap.c lib: Introduce generic min-heap 2020-03-06 11:56:59 +01:00
test_module.c
test_objagg.c test_objagg: Fix potential memory leak in error handling 2020-06-15 13:32:11 -07:00
test_overflow.c
test_parman.c
test_printf.c Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
test_rhashtable.c rhashtable: avoid -Wrestrict warning on overlapping sprintf output 2021-03-24 15:16:09 -07:00
test_scanf.c lib/test_scanf: split up number parsing test routines 2021-09-06 11:04:03 -07:00
test_siphash.c
test_sort.c lib/test: convert test_sort.c to use KUnit 2021-09-08 11:50:26 -07:00
test_stackinit.c lib/test_stackinit: Add assigned initializers 2021-08-22 00:21:36 -07:00
test_static_key_base.c
test_static_keys.c
test_string.c lib/test_string.c: allow module removal 2021-07-01 11:06:05 -07:00
test_strscpy.c
test_sysctl.c lib: test_sysctl: delete duplicated words 2020-10-16 11:11:20 -07:00
test_ubsan.c ubsan: remove CONFIG_UBSAN_OBJECT_SIZE 2022-04-13 20:59:27 +02:00
test_user_copy.c
test_uuid.c
test_vmalloc.c lib/test_vmalloc.c: add a new 'nr_pages' parameter 2021-09-03 09:58:14 -07:00
test_xarray.c XArray: Fix xas_create_range() when multi-order entry present 2022-04-08 14:24:09 +02:00
textsearch.c
timerqueue.c rbtree, timerqueue: Use rb_add_cached() 2021-02-17 14:08:01 +01:00
ts_bm.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00
ts_fsm.c Revert "lib: Revert use of fallthrough pseudo-keyword in lib/" 2020-11-18 14:15:17 -06:00
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 kunit: ubsan integration 2021-08-13 13:19:06 -06:00
ubsan.h ubsan: implement __ubsan_handle_alignment_assumption 2021-02-05 11:03:47 -08:00
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 uuid: Provide a GUID generator for raw buffer 2020-03-23 17:01:47 +01:00
vsprintf.c random: replace custom notifier chain with standard one 2022-05-30 09:29:10 +02:00
win_minmax.c
xarray.c XArray: Update the LRU list in xas_split() 2022-04-08 14:24:09 +02:00
xxhash.c lib/: replace HTTP links with HTTPS ones 2020-08-12 10:58:00 -07:00