* refs/heads/tmp-2fea039
Linux 4.4.106
usb: gadget: ffs: Forbid usb_ep_alloc_request from sleeping
arm: KVM: Fix VTTBR_BADDR_MASK BUG_ON off-by-one
Revert "x86/mm/pat: Ensure cpa->pfn only contains page frame numbers"
Revert "x86/efi: Hoist page table switching code into efi_call_virt()"
Revert "x86/efi: Build our own page table structures"
net/packet: fix a race in packet_bind() and packet_notifier()
packet: fix crash in fanout_demux_rollover()
sit: update frag_off info
rds: Fix NULL pointer dereference in __rds_rdma_map
tipc: fix memory leak in tipc_accept_from_sock()
more bio_map_user_iov() leak fixes
s390: always save and restore all registers on context switch
ipmi: Stop timers before cleaning up the module
audit: ensure that 'audit=1' actually enables audit for PID 1
ipvlan: fix ipv6 outbound device
afs: Connect up the CB.ProbeUuid
IB/mlx5: Assign send CQ and recv CQ of UMR QP
IB/mlx4: Increase maximal message size under UD QP
xfrm: Copy policy family in clone_policy
jump_label: Invoke jump_label_test() via early_initcall()
atm: horizon: Fix irq release error
sctp: use the right sk after waking up from wait_buf sleep
sctp: do not free asoc when it is already dead in sctp_sendmsg
sparc64/mm: set fields in deferred pages
block: wake up all tasks blocked in get_request()
sunrpc: Fix rpc_task_begin trace point
NFS: Fix a typo in nfs_rename()
dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0
lib/genalloc.c: make the avail variable an atomic_long_t
route: update fnhe_expires for redirect when the fnhe exists
route: also update fnhe_genid when updating a route cache
mac80211_hwsim: Fix memory leak in hwsim_new_radio_nl()
kbuild: pkg: use --transform option to prefix paths in tar
EDAC, i5000, i5400: Fix definition of NRECMEMB register
EDAC, i5000, i5400: Fix use of MTR_DRAM_WIDTH macro
powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested
drm/amd/amdgpu: fix console deadlock if late init failed
axonram: Fix gendisk handling
netfilter: don't track fragmented packets
zram: set physical queue limits to avoid array out of bounds accesses
i2c: riic: fix restart condition
crypto: s5p-sss - Fix completing crypto request in IRQ handler
ipv6: reorder icmpv6_init() and ip6_mr_init()
bnx2x: do not rollback VF MAC/VLAN filters we did not configure
bnx2x: fix possible overrun of VFPF multicast addresses array
bnx2x: prevent crash when accessing PTP with interface down
spi_ks8995: fix "BUG: key accdaa28 not in .data!"
arm64: KVM: Survive unknown traps from guests
arm: KVM: Survive unknown traps from guests
KVM: nVMX: reset nested_run_pending if the vCPU is going to be reset
irqchip/crossbar: Fix incorrect type of register size
scsi: lpfc: Fix crash during Hardware error recovery on SLI3 adapters
workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq
libata: drop WARN from protocol error in ata_sff_qc_issue()
kvm: nVMX: VMCLEAR should not cause the vCPU to shut down
USB: gadgetfs: Fix a potential memory leak in 'dev_config()'
usb: gadget: configs: plug memory leak
HID: chicony: Add support for another ASUS Zen AiO keyboard
gpio: altera: Use handle_level_irq when configured as a level_high
ARM: OMAP2+: Release device node after it is no longer needed.
ARM: OMAP2+: Fix device node reference counts
module: set __jump_table alignment to 8
selftest/powerpc: Fix false failures for skipped tests
x86/hpet: Prevent might sleep splat on resume
ARM: OMAP2+: gpmc-onenand: propagate error on initialization failure
vti6: Don't report path MTU below IPV6_MIN_MTU.
Revert "s390/kbuild: enable modversions for symbols exported from asm"
Revert "spi: SPI_FSL_DSPI should depend on HAS_DMA"
Revert "drm/armada: Fix compile fail"
mm: drop unused pmdp_huge_get_and_clear_notify()
thp: fix MADV_DONTNEED vs. numa balancing race
thp: reduce indentation level in change_huge_pmd()
scsi: storvsc: Workaround for virtual DVD SCSI version
ARM: avoid faulting on qemu
ARM: BUG if jumping to usermode address in kernel mode
arm64: fpsimd: Prevent registers leaking from dead tasks
KVM: VMX: remove I/O port 0x80 bypass on Intel hosts
arm64: KVM: fix VTTBR_BADDR_MASK BUG_ON off-by-one
media: dvb: i2c transfers over usb cannot be done from stack
drm/exynos: gem: Drop NONCONTIG flag for buffers allocated without IOMMU
drm: extra printk() wrapper macros
kdb: Fix handling of kallsyms_symbol_next() return value
s390: fix compat system call table
iommu/vt-d: Fix scatterlist offset handling
ALSA: usb-audio: Add check return value for usb_string()
ALSA: usb-audio: Fix out-of-bound error
ALSA: seq: Remove spurious WARN_ON() at timer check
ALSA: pcm: prevent UAF in snd_pcm_info
x86/PCI: Make broadcom_postcore_init() check acpi_disabled
X.509: reject invalid BIT STRING for subjectPublicKey
ASN.1: check for error from ASN1_OP_END__ACT actions
ASN.1: fix out-of-bounds read when parsing indefinite length item
efi: Move some sysfs files to be read-only by root
scsi: libsas: align sata_device's rps_resp on a cacheline
isa: Prevent NULL dereference in isa_bus driver callbacks
hv: kvp: Avoid reading past allocated blocks from KVP file
virtio: release virtio index when fail to device_register
can: usb_8dev: cancel urb on -EPIPE and -EPROTO
can: esd_usb2: cancel urb on -EPIPE and -EPROTO
can: ems_usb: cancel urb on -EPIPE and -EPROTO
can: kvaser_usb: cancel urb on -EPIPE and -EPROTO
can: kvaser_usb: ratelimit errors if incomplete messages are received
can: kvaser_usb: Fix comparison bug in kvaser_usb_read_bulk_callback()
can: kvaser_usb: free buf in error paths
can: ti_hecc: Fix napi poll return value for repoll
BACKPORT: irq: Make the irqentry text section unconditional
UPSTREAM: arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections
UPSTREAM: x86, kasan, ftrace: Put APIC interrupt handlers into .irqentry.text
UPSTREAM: kasan: make get_wild_bug_type() static
UPSTREAM: kasan: separate report parts by empty lines
UPSTREAM: kasan: improve double-free report format
UPSTREAM: kasan: print page description after stacks
UPSTREAM: kasan: improve slab object description
UPSTREAM: kasan: change report header
UPSTREAM: kasan: simplify address description logic
UPSTREAM: kasan: change allocation and freeing stack traces headers
UPSTREAM: kasan: unify report headers
UPSTREAM: kasan: introduce helper functions for determining bug type
BACKPORT: kasan: report only the first error by default
UPSTREAM: kasan: fix races in quarantine_remove_cache()
UPSTREAM: kasan: resched in quarantine_remove_cache()
BACKPORT: kasan, sched/headers: Uninline kasan_enable/disable_current()
BACKPORT: kasan: drain quarantine of memcg slab objects
UPSTREAM: kasan: eliminate long stalls during quarantine reduction
UPSTREAM: kasan: support panic_on_warn
UPSTREAM: x86/suspend: fix false positive KASAN warning on suspend/resume
UPSTREAM: kasan: support use-after-scope detection
UPSTREAM: kasan/tests: add tests for user memory access functions
UPSTREAM: mm, kasan: add a ksize() test
UPSTREAM: kasan: test fix: warn if the UAF could not be detected in kmalloc_uaf2
UPSTREAM: kasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right()
UPSTREAM: lib/stackdepot: export save/fetch stack for drivers
UPSTREAM: lib/stackdepot.c: bump stackdepot capacity from 16MB to 128MB
BACKPORT: kprobes: Unpoison stack in jprobe_return() for KASAN
UPSTREAM: kasan: remove the unnecessary WARN_ONCE from quarantine.c
UPSTREAM: kasan: avoid overflowing quarantine size on low memory systems
UPSTREAM: kasan: improve double-free reports
BACKPORT: mm: coalesce split strings
BACKPORT: mm/kasan: get rid of ->state in struct kasan_alloc_meta
UPSTREAM: mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta
UPSTREAM: mm: kasan: remove unused 'reserved' field from struct kasan_alloc_meta
UPSTREAM: mm/kasan, slub: don't disable interrupts when object leaves quarantine
UPSTREAM: mm/kasan: don't reduce quarantine in atomic contexts
UPSTREAM: mm/kasan: fix corruptions and false positive reports
UPSTREAM: lib/stackdepot.c: use __GFP_NOWARN for stack allocations
BACKPORT: mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB
UPSTREAM: kasan/quarantine: fix bugs on qlist_move_cache()
UPSTREAM: mm: mempool: kasan: don't poot mempool objects in quarantine
UPSTREAM: kasan: change memory hot-add error messages to info messages
BACKPORT: mm/kasan: add API to check memory regions
UPSTREAM: mm/kasan: print name of mem[set,cpy,move]() caller in report
UPSTREAM: mm: kasan: initial memory quarantine implementation
UPSTREAM: lib/stackdepot: avoid to return 0 handle
UPSTREAM: lib/stackdepot.c: allow the stack trace hash to be zero
UPSTREAM: mm, kasan: fix compilation for CONFIG_SLAB
BACKPORT: mm, kasan: stackdepot implementation. Enable stackdepot for SLAB
BACKPORT: mm, kasan: add GFP flags to KASAN API
UPSTREAM: mm, kasan: SLAB support
UPSTREAM: mm/slab: align cache size first before determination of OFF_SLAB candidate
UPSTREAM: mm/slab: use more appropriate condition check for debug_pagealloc
UPSTREAM: mm/slab: factor out debugging initialization in cache_init_objs()
UPSTREAM: mm/slab: remove object status buffer for DEBUG_SLAB_LEAK
UPSTREAM: mm/slab: alternative implementation for DEBUG_SLAB_LEAK
UPSTREAM: mm/slab: clean up DEBUG_PAGEALLOC processing code
UPSTREAM: mm/slab: activate debug_pagealloc in SLAB when it is actually enabled
sched: EAS/WALT: Don't take into account of running task's util
BACKPORT: schedutil: Reset cached freq if it is not in sync with next_freq
UPSTREAM: kasan: add functions to clear stack poison
Conflicts:
arch/arm/include/asm/kvm_arm.h
arch/arm64/kernel/vmlinux.lds.S
include/linux/kasan.h
kernel/softirq.c
lib/Kconfig
lib/Kconfig.kasan
lib/Makefile
lib/stackdepot.c
mm/kasan/kasan.c
sound/usb/mixer.c
Change-Id: If70ced6da5f19be3dd92d10a8d8cd4d5841e5870
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
For KASAN builds:
- switch SLUB allocator to using stackdepot instead of storing the
allocation/deallocation stacks in the objects;
- change the freelist hook so that parts of the freelist can be put
into the quarantine.
[aryabinin@virtuozzo.com: fixes]
Link: http://lkml.kernel.org/r/1468601423-28676-1-git-send-email-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/1468347165-41906-3-git-send-email-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 64145065
(cherry-picked from 80a9201a5965f4715d5c09790862e0df84ce0614)
Change-Id: I2b59c6d50d0db62d3609edfdc7be54e48f8afa5c
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Implement the stack depot and provide CONFIG_STACKDEPOT. Stack depot
will allow KASAN store allocation/deallocation stack traces for memory
chunks. The stack traces are stored in a hash table and referenced by
handles which reside in the kasan_alloc_meta and kasan_free_meta
structures in the allocated memory chunks.
IRQ stack traces are cut below the IRQ entry point to avoid unnecessary
duplication.
Right now stackdepot support is only enabled in SLAB allocator. Once
KASAN features in SLAB are on par with those in SLUB we can switch SLUB
to stackdepot as well, thus removing the dependency on SLUB stack
bookkeeping, which wastes a lot of memory.
This patch is based on the "mm: kasan: stack depots" patch originally
prepared by Dmitry Chernenkov.
Joonsoo has said that he plans to reuse the stackdepot code for the
mm/page_owner.c debugging facility.
[akpm@linux-foundation.org: s/depot_stack_handle/depot_stack_handle_t]
[aryabinin@virtuozzo.com: comment style fixes]
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 64145065
(cherry-picked from cd11016e5f5212c13c0cec7384a525edc93b4921)
Change-Id: Ic804318410823b95d84e264a6334e018f21ef943
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Add KASAN hooks to SLAB allocator.
This patch is based on the "mm: kasan: unified support for SLUB and SLAB
allocators" patch originally prepared by Dmitry Chernenkov.
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 64145065
(cherry-picked from 7ed2f9e663854db313f177a511145630e398b402)
Change-Id: I131fdafc1c27a25732475f5bbd1653b66954e1b7
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Allow enabling KASAN on a per-directory or per-file basis rather than
for the entire kernel.
Change-Id: I9a491d3ab0df4c42302a258b9edb3b78cf4e1db0
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
[satyap: trivial merge conflict resolution]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
It's recommended to have slub's user tracking enabled with CONFIG_KASAN,
because:
a) User tracking disables slab merging which improves
detecting out-of-bounds accesses.
b) User tracking metadata acts as redzone which also improves
detecting out-of-bounds accesses.
c) User tracking provides additional information about object.
This information helps to understand bugs.
Currently it is not enabled by default. Besides recompiling the kernel
with KASAN and reinstalling it, user also have to change the boot cmdline,
which is not very handy.
Enable slub user tracking by default with KASAN=y, since there is no good
reason to not do this.
[akpm@linux-foundation.org: little fixes, per David]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KASAN_SHADOW_OFFSET is purely arch specific setting,
so it should be in arch's Kconfig file.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435828178-10975-7-git-send-email-a.ryabinin@samsung.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The documentation shows a need for gcc > 4.9.2, but it's really >=. The
Kconfig entries don't show require versions so add them. Correct a
latter/later typo too. Also mention that gcc 5 required to catch out of
bounds accesses to global and stack variables.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This feature let us to detect accesses out of bounds of global variables.
This will work as for globals in kernel image, so for globals in modules.
Currently this won't work for symbols in user-specified sections (e.g.
__init, __read_mostly, ...)
The idea of this is simple. Compiler increases each global variable by
redzone size and add constructors invoking __asan_register_globals()
function. Information about global variable (address, size, size with
redzone ...) passed to __asan_register_globals() so we could poison
variable's redzone.
This patch also forces module_alloc() to return 8*PAGE_SIZE aligned
address making shadow memory handling (
kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment
guarantees that each shadow page backing modules address space correspond
to only one module_alloc() allocation.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a test module doing various nasty things like out of bounds
accesses, use after free. It is useful for testing kernel debugging
features like kernel address sanitizer.
It mostly concentrates on testing of slab allocator, but we might want to
add more different stuff here in future (like stack/global variables out
of bounds accesses and so on).
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With this patch kasan will be able to catch bugs in memory allocated by
slub. Initially all objects in newly allocated slab page, marked as
redzone. Later, when allocation of slub object happens, requested by
caller number of bytes marked as accessible, and the rest of the object
(including slub's metadata) marked as redzone (inaccessible).
We also mark object as accessible if ksize was called for this object.
There is some places in kernel where ksize function is called to inquire
size of really allocated area. Such callers could validly access whole
allocated memory, so it should be marked as accessible.
Code in slub.c and slab_common.c files could validly access to object's
metadata, so instrumentation for this files are disabled.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Dmitry Chernenkov <dmitryc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds arch specific code for kernel address sanitizer.
16TB of virtual addressed used for shadow memory. It's located in range
[ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup
stacks.
At early stage we map whole shadow region with zero page. Latter, after
pages mapped to direct mapping address range we unmap zero pages from
corresponding shadow (see kasan_map_shadow()) and allocate and map a real
shadow memory reusing vmemmap_populate() function.
Also replace __pa with __pa_nodebug before shadow initialized. __pa with
CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr)
__phys_addr is instrumented, so __asan_load could be called before shadow
area initialized.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel Address sanitizer (KASan) is a dynamic memory error detector. It
provides fast and comprehensive solution for finding use-after-free and
out-of-bounds bugs.
KASAN uses compile-time instrumentation for checking every memory access,
therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with
putting symbol aliases into the wrong section, which breaks kasan
instrumentation of globals.
This patch only adds infrastructure for kernel address sanitizer. It's
not available for use yet. The idea and some code was borrowed from [1].
Basic idea:
The main idea of KASAN is to use shadow memory to record whether each byte
of memory is safe to access or not, and use compiler's instrumentation to
check the shadow memory on each memory access.
Address sanitizer uses 1/8 of the memory addressable in kernel for shadow
memory and uses direct mapping with a scale and offset to translate a
memory address to its corresponding shadow address.
Here is function to translate address to corresponding shadow address:
unsigned long kasan_mem_to_shadow(unsigned long addr)
{
return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET;
}
where KASAN_SHADOW_SCALE_SHIFT = 3.
So for every 8 bytes there is one corresponding byte of shadow memory.
The following encoding used for each shadow byte: 0 means that all 8 bytes
of the corresponding memory region are valid for access; k (1 <= k <= 7)
means that the first k bytes are valid for access, and other (8 - k) bytes
are not; Any negative value indicates that the entire 8-bytes are
inaccessible. Different negative values used to distinguish between
different kinds of inaccessible memory (redzones, freed memory) (see
mm/kasan/kasan.h).
To be able to detect accesses to bad memory we need a special compiler.
Such compiler inserts a specific function calls (__asan_load*(addr),
__asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16.
These functions check whether memory region is valid to access or not by
checking corresponding shadow memory. If access is not valid an error
printed.
Historical background of the address sanitizer from Dmitry Vyukov:
"We've developed the set of tools, AddressSanitizer (Asan),
ThreadSanitizer and MemorySanitizer, for user space. We actively use
them for testing inside of Google (continuous testing, fuzzing,
running prod services). To date the tools have found more than 10'000
scary bugs in Chromium, Google internal codebase and various
open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and
lots of others): [2] [3] [4].
The tools are part of both gcc and clang compilers.
We have not yet done massive testing under the Kernel AddressSanitizer
(it's kind of chicken and egg problem, you need it to be upstream to
start applying it extensively). To date it has found about 50 bugs.
Bugs that we've found in upstream kernel are listed in [5].
We've also found ~20 bugs in out internal version of the kernel. Also
people from Samsung and Oracle have found some.
[...]
As others noted, the main feature of AddressSanitizer is its
performance due to inline compiler instrumentation and simple linear
shadow memory. User-space Asan has ~2x slowdown on computational
programs and ~2x memory consumption increase. Taking into account that
kernel usually consumes only small fraction of CPU and memory when
running real user-space programs, I would expect that kernel Asan will
have ~10-30% slowdown and similar memory consumption increase (when we
finish all tuning).
I agree that Asan can well replace kmemcheck. We have plans to start
working on Kernel MemorySanitizer that finds uses of unitialized
memory. Asan+Msan will provide feature-parity with kmemcheck. As
others noted, Asan will unlikely replace debug slab and pagealloc that
can be enabled at runtime. Asan uses compiler instrumentation, so even
if it is disabled, it still incurs visible overheads.
Asan technology is easily portable to other architectures. Compiler
instrumentation is fully portable. Runtime has some arch-dependent
parts like shadow mapping and atomic operation interception. They are
relatively easy to port."
Comparison with other debugging features:
========================================
KMEMCHECK:
- KASan can do almost everything that kmemcheck can. KASan uses
compile-time instrumentation, which makes it significantly faster than
kmemcheck. The only advantage of kmemcheck over KASan is detection of
uninitialized memory reads.
Some brief performance testing showed that kasan could be
x500-x600 times faster than kmemcheck:
$ netperf -l 30
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
no debug: 87380 16384 16384 30.00 41624.72
kasan inline: 87380 16384 16384 30.00 12870.54
kasan outline: 87380 16384 16384 30.00 10586.39
kmemcheck: 87380 16384 16384 30.03 20.23
- Also kmemcheck couldn't work on several CPUs. It always sets
number of CPUs to 1. KASan doesn't have such limitation.
DEBUG_PAGEALLOC:
- KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page
granularity level, so it able to find more bugs.
SLUB_DEBUG (poisoning, redzones):
- SLUB_DEBUG has lower overhead than KASan.
- SLUB_DEBUG in most cases are not able to detect bad reads,
KASan able to detect both reads and writes.
- In some cases (e.g. redzone overwritten) SLUB_DEBUG detect
bugs only on allocation/freeing of object. KASan catch
bugs right before it will happen, so we always know exact
place of first bad read/write.
[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
[2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs
[3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs
[4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs
[5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies
Based on work by Andrey Konovalov.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Srinivasarao P
Paul Lawrence
Alexander Potapenko
Patrick Daly
Andrey Ryabinin
Andrey Ryabinin
Joe Perches