linux/lib
Lai Jiangshan 2ada32b01b idr: fix overflow bug during maximum ID calculation at maximum height
commit 3afb69cb55 upstream.

idr_replace() open-codes the logic to calculate the maximum valid ID
given the height of the idr tree; unfortunately, the open-coded logic
doesn't account for the fact that the top layer may have unused slots
and over-shifts the limit to zero when the tree is at its maximum
height.

The following test code shows it fails to replace the value for
id=((1<<27)+42):

  static void test5(void)
  {
        int id;
        DEFINE_IDR(test_idr);
  #define TEST5_START ((1<<27)+42) /* use the highest layer */

        printk(KERN_INFO "Start test5\n");
        id = idr_alloc(&test_idr, (void *)1, TEST5_START, 0, GFP_KERNEL);
        BUG_ON(id != TEST5_START);
        TEST_BUG_ON(idr_replace(&test_idr, (void *)2, TEST5_START) != (void *)1);
        idr_destroy(&test_idr);
        printk(KERN_INFO "End of test5\n");
  }

Fix the bug by using idr_max() which correctly takes into account the
maximum allowed shift.

sub_alloc() shares the same problem and may incorrectly fail with
-EAGAIN; however, this bug doesn't affect correct operation because
idr_get_empty_slot(), which already uses idr_max(), retries with the
increased @id in such cases.

[tj@kernel.org: Updated patch description.]
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-30 20:09:42 -07:00
..
lzo lzo: properly check for overruns 2014-06-26 15:12:41 -04:00
mpi lib/mpi/mpicoder.c: looping issue, need stop when equal to zero, found by 'EXTRA_FLAGS=-W'. 2013-06-12 16:29:44 -07:00
raid6
reed_solomon
xz decompressors: fix typo "POWERPC" 2013-03-13 15:21:48 -07:00
zlib_deflate
zlib_inflate
.gitignore
argv_split.c argv_split(): teach it to handle mutable strings 2013-04-29 18:28:19 -07:00
asn1_decoder.c
atomic64_test.c
atomic64.c
audit.c
average.c
bcd.c
bch.c
bitmap.c
bitrev.c
bsearch.c
btree.c
bug.c
build_OID_registry
bust_spinlocks.c printk: Provide a wake_up_klogd() off-case 2013-03-22 16:41:20 -07:00
check_signature.c
checksum.c
clz_tab.c
cmdline.c
cordic.c
cpu_rmap.c
cpu-notifier-error-inject.c
cpumask.c
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
ctype.c
debug_locks.c
debugobjects.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c lib/decompressors: fix "no limit" output buffer length 2014-02-06 11:08:12 -08:00
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c lib/decompress.c: fix initconst 2013-04-30 17:04:09 -07:00
devres.c lib/devres.c: fix misplaced #endif 2013-02-27 19:10:09 -08:00
digsig.c
div64.c Revert "math64: New div64_u64_rem helper" 2013-04-30 19:13:05 +02:00
dma-debug.c dma-debug: update DMA debug API to better handle multiple mappings of a buffer 2013-03-22 16:41:20 -07:00
dump_stack.c dump_stack: consolidate dump_stack() implementations and unify their behaviors 2013-04-30 17:04:02 -07:00
dynamic_debug.c dynamic_debug: reuse generic string_unescape function 2013-04-30 17:04:03 -07:00
dynamic_queue_limits.c
earlycpio.c
extable.c
fault-inject.c lib/: rename random32() to prandom_u32() 2013-04-29 18:28:42 -07:00
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_last_bit.c
find_next_bit.c
flex_array.c
flex_proportions.c
gcd.c
gen_crc32table.c
genalloc.c lib/genalloc.c: fix overflow of ending address of memory chunk 2013-12-11 22:36:28 -08:00
halfmd4.c
hexdump.c
hweight.c
idr.c idr: fix overflow bug during maximum ID calculation at maximum height 2014-06-30 20:09:42 -07:00
inflate.c
int_sqrt.c lib/int_sqrt.c: optimize square root algorithm 2013-04-29 18:28:19 -07:00
interval_tree_test_main.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
ioremap.c
iovec.c Hoist memcpy_fromiovec/memcpy_toiovec into lib/ 2013-05-20 10:24:22 +09:30
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
Kconfig Move utf16 functions to kernel core and rename 2013-04-15 21:23:03 +01:00
Kconfig.debug lib/Kconfig.debug: Restrict FRAME_POINTER for MIPS 2013-07-28 16:30:12 -07:00
Kconfig.kgdb KGDB/KDB fixes and cleanups 2013-03-02 08:31:39 -08:00
Kconfig.kmemcheck
kfifo.c kfifo: fix kfifo_alloc() and kfifo_init() 2013-02-27 19:10:23 -08:00
klist.c klist: del waiter from klist_remove_waiters before wakeup waitting process 2013-05-21 10:16:39 -07:00
kobject_uevent.c
kobject.c kref: minor cleanup 2013-05-07 16:09:00 -07:00
kstrtox.c
kstrtox.h
lcm.c
libcrc32c.c
list_debug.c
list_sort.c lib/: rename random32() to prandom_u32() 2013-04-29 18:28:42 -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-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
lru_cache.c lru_cache: introduce lc_get_cumulative() 2013-03-22 22:17:36 -06:00
Makefile x86, hweight: Fix BUG when booting with CONFIG_GCOV_PROFILE_ALL=y 2014-02-20 11:06:11 -08:00
md5.c
memory-notifier-error-inject.c
memweight.c
nlattr.c netlink: rate-limit leftover bytes warning and print process name 2014-06-26 15:12:37 -04:00
notifier-error-inject.c mode_t, whack-a-mole at 11... 2013-04-09 14:13:05 -04:00
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c Give the OID registry file module info to avoid kernel tainting 2013-05-05 14:38:00 -07:00
parser.c
pci_iomap.c
percpu_counter.c
percpu-rwsem.c
plist.c
pm-notifier-error-inject.c
prio_heap.c
proportions.c
radix-tree.c
random32.c random32: fix off-by-one in seeding requirement 2013-12-08 07:29:24 -08:00
ratelimit.c
rational.c
rbtree_test.c rbtree_test: add __init/__exit annotations 2013-04-30 17:04:07 -07:00
rbtree.c
reciprocal_div.c
rwsem-spinlock.c rwsem: simplify __rwsem_do_wake 2013-05-07 07:20:16 -07:00
rwsem.c rwsem: check counter to avoid cmpxchg calls 2013-05-07 16:11:51 -07:00
scatterlist.c lib/scatterlist.c: don't flush_kernel_dcache_page on slab page 2013-11-13 12:05:33 +09:00
sha1.c
show_mem.c mm, show_mem: suppress page counts in non-blockable contexts 2013-04-29 15:54:28 -07:00
smp_processor_id.c
sort.c
spinlock_debug.c
stmp_device.c
string_helpers.c lib/string_helpers: introduce generic string_unescape 2013-04-30 17:04:03 -07:00
string.c
strncpy_from_user.c
strnlen_user.c
swiotlb.c x86, kdump: Set crashkernel_low automatically 2013-04-17 12:35:32 -07:00
syscall.c
test-kstrtox.c
test-string_helpers.c lib/string_helpers: introduce generic string_unescape 2013-04-30 17:04:03 -07:00
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ucs2_string.c Move utf16 functions to kernel core and rename 2013-04-15 21:23:03 +01:00
usercopy.c Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2013-04-30 17:04:09 -07:00
uuid.c uuid: use prandom_bytes() 2013-04-29 18:28:42 -07:00
vsprintf.c vsprintf: check real user/group id for %pK 2013-12-04 10:56:06 -08:00