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841a915d20
linux/lib
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Steven Rostedt (VMware) 841a915d20 vsprintf: Do not have bprintf dereference pointers 
When trace_printk() was introduced, it was discussed that making it be as
low overhead as possible, that the processing of the format string should be
delayed until it is read. That is, a "trace_printk()" should not convert
the %d into numbers and so on, but instead, save the fmt string and all the
args in the buffer at the time of recording. When the trace_printk() data is
read, it would then parse the format string and do the conversions of the
saved arguments in the tracing buffer.

The code to perform this was added to vsprintf where vbin_printf() would
save the arguments of a specified format string in a buffer, then
bstr_printf() could be used to convert the buffer with the same format
string into the final output, as if vsprintf() was called in one go.

The issue arises when dereferenced pointers are used. The problem is that
something like %*pbl which reads a bitmask, will save the pointer to the
bitmask in the buffer. Then the reading of the buffer via bstr_printf() will
then look at the pointer to process the final output. Obviously the value of
that pointer could have changed since the time it was recorded to the time
the buffer is read. Worse yet, the bitmask could be unmapped, and the
reading of the trace buffer could actually cause a kernel oops.

Another problem is that user space tools such as perf and trace-cmd do not
have access to the contents of these pointers, and they become useless when
the tracing buffer is extracted.

Instead of having vbin_printf() simply save the pointer in the buffer for
later processing, have it perform the formatting at the time bin_printf() is
called. This will fix the issue of dereferencing pointers at a later time,
and has the extra benefit of having user space tools understand these
values.

Since perf and trace-cmd already can handle %p[sSfF] via saving kallsyms,
their pointers are saved and not processed during vbin_printf(). If they
were converted, it would break perf and trace-cmd, as they would not know
how to deal with the conversion.

Link: http://lkml.kernel.org/r/20171228204025.14a71d8f@gandalf.local.home

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-23 15:57:30 -05:00
..
842 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fonts License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lz4 lib/lz4: make arrays static const, reduces object code size 2017-10-03 17:54:25 -07:00
lzo License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpi lib/mpi: Fix umul_ppmm() for MIPS64r6 2017-12-22 19:39:09 +11:00
raid6 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
reed_solomon
xz lib/xz: Add fall-through comments to a switch statement 2017-10-12 15:10:12 +02:00
zlib_deflate
zlib_inflate lib/zlib_inflate/inftrees.c: fix potential buffer overflow 2017-05-08 17:15:12 -07:00
zstd lib: Add zstd modules 2017-08-15 09:02:08 -07:00
.gitignore
argv_split.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ashldi3.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
ashrdi3.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
asn1_decoder.c ASN.1: check for error from ASN1_OP_END__ACT actions 2017-12-08 15:13:27 +00:00
assoc_array.c Merge branch 'linus' into locking/core, to resolve conflicts 2017-11-07 10:32:44 +01:00
atomic64_test.c lib/atomic64_test.c: add a test that atomic64_inc_not_zero() returns an int 2017-07-14 15:05:13 -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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bcd.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bch.c
bitmap.c documentation: kernel-api: add more info on bitmap functions 2017-10-19 13:01:40 -06:00
bitrev.c
bsearch.c lib/bsearch.c: micro-optimize pivot position calculation 2017-07-10 16:32:35 -07:00
btree.c
bug.c bug: define the "cut here" string in a single place 2017-11-17 16:10:01 -08:00
build_OID_registry
bust_spinlocks.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
chacha20.c random: replace non-blocking pool with a Chacha20-based CRNG 2016-07-03 00:57:23 -04:00
check_signature.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
checksum.c
clz_ctz.c
clz_tab.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cmdline.c lib/cmdline.c: remove meaningless comment 2017-09-08 18:26:49 -07:00
cmpdi2.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
compat_audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cordic.c
cpu_rmap.c
cpumask.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crc4.c docs: clean up and add rest of CRC functions to kernel-api.rst 2017-09-26 15:01:20 -06:00
crc7.c
crc8.c docs: clean up and add rest of CRC functions to kernel-api.rst 2017-09-26 15:01:20 -06:00
crc16.c
crc32.c docs: clean up and add rest of CRC functions to kernel-api.rst 2017-09-26 15:01:20 -06:00
crc32defs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crc32test.c lib: add module support to crc32 tests 2017-02-24 17:46:57 -08:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug_info.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
debug_locks.c
debugobjects.c debugobjects: Make kmemleak ignore debug objects 2017-08-14 16:51:01 +02:00
dec_and_lock.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
decompress_bunzip2.c
decompress_inflate.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
decompress_unlz4.c lib/decompress_unlz4: change module to work with new LZ4 module version 2017-02-24 17:46:57 -08:00
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
devres.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
digsig.c lib/digsig: fix dereference of NULL user_key_payload 2017-10-12 17:16:40 +01:00
div64.c A relatively calm cycle for the docs tree again. 2017-11-13 08:25:06 -08:00
dma-debug.c lib/dma-debug.c: fix incorrect pfn calculation 2017-11-17 16:10:00 -08:00
dma-noop.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dma-virt.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dump_stack.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dynamic_debug.c dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0 2017-11-17 16:10:01 -08:00
dynamic_queue_limits.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
earlycpio.c lib/cpio: Make find_cpio_data()'s offset arg optional 2016-06-08 11:04:19 +02:00
errseq.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
extable.c lib/extable.c: use bsearch() library function in search_extable() 2017-07-10 16:32:35 -07:00
fault-inject.c fault-inject: fix wrong should_fail() decision in task context 2017-08-10 15:54:06 -07:00
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit.c lib/find_bit.c: micro-optimise find_next_*_bit 2017-02-24 17:46:57 -08:00
flex_array.c
flex_proportions.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
gcd.c lib/gcd: add kernel-doc notation 2017-10-07 10:45:14 -06:00
gen_crc32table.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
genalloc.c lib/genalloc.c: make the avail variable an atomic_long_t 2017-11-17 16:10:02 -08:00
glob.c lib: add module support to glob tests 2017-02-24 17:46:57 -08:00
globtest.c lib: add module support to glob tests 2017-02-24 17:46:57 -08:00
hexdump.c lib/hexdump.c: return -EINVAL in case of error in hex2bin() 2017-09-08 18:26:49 -07:00
hweight.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
idr.c mm, truncate: do not check mapping for every page being truncated 2017-11-15 18:21:06 -08:00
inflate.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
int_sqrt.c lib/int_sqrt: adjust comments 2017-11-17 16:10:01 -08:00
interval_tree_test.c lib/rbtree-test: lower default params 2017-11-17 16:10:02 -08:00
interval_tree.c
iomap_copy.c
iomap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iommu-common.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iommu-helper.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ioremap.c License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
iov_iter.c new primitive: iov_iter_for_each_range() 2017-10-11 22:36:54 -04:00
irq_poll.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq_regs.c
is_single_threaded.c sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
jedec_ddr_data.c
kasprintf.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig This pull request contains the following core changes: 2017-11-22 20:46:06 -10:00
Kconfig.debug locking/lockdep: Remove the cross-release locking checks 2017-12-12 12:38:51 +01:00
Kconfig.kasan mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB 2016-07-28 16:07:41 -07:00
Kconfig.kgdb lib: update location of kgdb documentation 2017-05-16 08:44:22 -03:00
Kconfig.ubsan Kconfig: lib/Kconfig.ubsan fix reference to ubsan documentation 2016-12-14 16:04:08 -08:00
kfifo.c
klist.c
kobject_uevent.c kobject: fix suppressing modalias in uevents delivered over netlink 2017-12-21 11:10:33 +01:00
kobject.c kobject: Export kobject_get_unless_zero() 2017-03-22 20:11:35 -06:00
kstrtox.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kstrtox.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lcm.c
libcrc32c.c crypto: Work around deallocated stack frame reference gcc bug on sparc. 2017-06-08 17:36:03 +08:00
list_debug.c bug: switch data corruption check to __must_check 2017-02-24 17:46:56 -08:00
list_sort.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
llist.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
locking-selftest-hardirq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-mutex.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-rsem.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-rtmutex.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-softirq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest-wsem.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
locking-selftest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lockref.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
lru_cache.c
lshrdi3.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
Makefile lib: test module for find_*_bit() functions 2017-11-17 16:10:02 -08:00
memory-notifier-error-inject.c
memweight.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
muldi3.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
net_utils.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
netdev-notifier-error-inject.c
nlattr.c netlink: Relax attr validation for fixed length types 2017-12-07 14:00:57 -05:00
nmi_backtrace.c lib/nmi_backtrace.c: fix kernel text address leak 2017-11-17 16:10:02 -08:00
nodemask.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
notifier-error-inject.c
notifier-error-inject.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
of-reconfig-notifier-error-inject.c
oid_registry.c 509: fix printing uninitialized stack memory when OID is empty 2017-12-08 15:13:28 +00:00
once.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
parman.c lib: Introduce priority array area manager 2017-02-03 16:35:42 -05:00
parser.c parser: add u64 number parser 2016-12-06 10:17:03 +02:00
pci_iomap.c
percpu_counter.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
percpu_ida.c sched/headers: Prepare to remove the <linux/gfp.h> include from <linux/sched.h> 2017-03-02 08:42:34 +01:00
percpu_test.c
percpu-refcount.c percpu-refcount: support synchronous switch to atomic mode. 2017-03-22 19:18:43 -07:00
plist.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
pm-notifier-error-inject.c
prime_numbers.c lib/prime_numbers: Suppress warn on kmalloc failure 2017-01-23 09:17:12 +01:00
radix-tree.c mm, truncate: do not check mapping for every page being truncated 2017-11-15 18:21:06 -08:00
random32.c treewide: Switch DEFINE_TIMER callbacks to struct timer_list * 2017-11-21 15:57:05 -08:00
ratelimit.c lib/ratelimit.c: use deferred printk() version 2017-10-03 17:54:26 -07:00
rational.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rbtree_test.c lib/rbtree-test: lower default params 2017-11-17 16:10:02 -08:00
rbtree.c lib/rbtree,drm/mm: add rbtree_replace_node_cached() 2017-12-14 16:00:48 -08:00
reciprocal_div.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
refcount.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rhashtable.c rhashtable: Documentation tweak 2017-09-19 15:18:33 -07:00
sbitmap.c sbitmap: add sbitmap_get_shallow() operation 2017-04-14 14:06:52 -06:00
scatterlist.c lib/scatterlist: Introduce and export __sg_alloc_table_from_pages 2017-09-07 10:48:29 +01:00
seq_buf.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sg_pool.c
sg_split.c
sha1.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
show_mem.c lib/show_mem.c: teach show_mem to work with the given nodemask 2017-02-22 16:41:30 -08:00
siphash.c siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
smp_processor_id.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sort.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
stackdepot.c lib/stackdepot: export save/fetch stack for drivers 2016-11-11 08:12:37 -08:00
stmp_device.c
string_helpers.c mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
string.c lib: add module support to string tests 2017-11-17 16:10:01 -08:00
strncpy_from_user.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
strnlen_user.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swiotlb.c x86/mm: Add DMA support for SEV memory encryption 2017-11-07 15:35:58 +01:00
syscall.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
test_bitmap.c lib/test_bitmap.c: use ULL suffix for 64-bit constants 2017-09-13 18:53:15 -07:00
test_bpf.c bpf: introduce BPF_JIT_ALWAYS_ON config 2018-01-09 22:25:26 +01:00
test_debug_virtual.c lib: add test module for CONFIG_DEBUG_VIRTUAL 2017-09-08 18:26:49 -07:00
test_find_bit.c lib: test module for find_*_bit() functions 2017-11-17 16:10:02 -08:00
test_firmware.c test_firmware: add batched firmware tests 2017-08-10 13:58:41 -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_kasan.c lib/test: delete five error messages for failed memory allocations 2017-11-17 16:10:01 -08:00
test_kmod.c lib/test: delete five error messages for failed memory allocations 2017-11-17 16:10:01 -08:00
test_list_sort.c lib/test: delete five error messages for failed memory allocations 2017-11-17 16:10:01 -08:00
test_module.c
test_parman.c lib: fix spelling mistake: "actualy" -> "actually" 2017-02-26 11:03:38 -05:00
test_printf.c printk: hash addresses printed with %p 2017-11-29 12:09:02 +11:00
test_rhashtable.c test_rhashtable: remove initdata annotation 2017-09-21 20:40:55 -07:00
test_siphash.c siphash: implement HalfSipHash1-3 for hash tables 2017-01-09 13:58:57 -05:00
test_sort.c Revert "lib/test_sort.c: make it explicitly non-modular" 2017-05-08 17:15:10 -07:00
test_static_key_base.c
test_static_keys.c
test_string.c lib: add module support to string tests 2017-11-17 16:10:01 -08:00
test_sysctl.c test_sysctl: test against int proc_dointvec() array support 2017-07-12 16:26:00 -07:00
test_user_copy.c lib: remove check for AVR32 arch in test_user_copy 2017-05-01 09:36:30 +02:00
test_uuid.c uuid: fix incorrect uuid_equal conversion in test_uuid_test 2017-07-21 09:38:30 +02:00
test-kstrtox.c
test-string_helpers.c
textsearch.c
timerqueue.c timerqueue: Document return values of timerqueue_add/del() 2017-12-29 23:13:10 +01:00
ts_bm.c
ts_fsm.c textsearch: fix typos in library helpers 2017-10-22 03:14:07 +01:00
ts_kmp.c textsearch: fix typos in library helpers 2017-10-22 03:14:07 +01:00
ubsan.c UBSAN: fix typo in format string 2016-08-02 17:31:41 -04:00
ubsan.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ucmpdi2.c move libgcc.h to include/linux 2017-12-01 13:09:40 -08:00
ucs2_string.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
usercopy.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
uuid.c uuid: hoist uuid_is_null() helper from libnvdimm 2017-06-05 16:59:05 +02:00
vsprintf.c vsprintf: Do not have bprintf dereference pointers 2018-01-23 15:57:30 -05:00
win_minmax.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xxhash.c lib: Add xxhash module 2017-08-15 09:02:07 -07:00