linux-stable.git/include/linux, branch v4.4.294

siphash: use _unaligned version by default

2021-12-08T07:44:08+00:00

commit f7e5b9bfa6c8820407b64eabc1f29c9a87e8993d upstream.

On ARM v6 and later, we define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
because the ordinary load/store instructions (ldr, ldrh, ldrb) can
tolerate any misalignment of the memory address. However, load/store
double and load/store multiple instructions (ldrd, ldm) may still only
be used on memory addresses that are 32-bit aligned, and so we have to
use the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS macro with care, or we
may end up with a severe performance hit due to alignment traps that
require fixups by the kernel. Testing shows that this currently happens
with clang-13 but not gcc-11. In theory, any compiler version can
produce this bug or other problems, as we are dealing with undefined
behavior in C99 even on architectures that support this in hardware,
see also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363.

Fortunately, the get_unaligned() accessors do the right thing: when
building for ARMv6 or later, the compiler will emit unaligned accesses
using the ordinary load/store instructions (but avoid the ones that
require 32-bit alignment). When building for older ARM, those accessors
will emit the appropriate sequence of ldrb/mov/orr instructions. And on
architectures that can truly tolerate any kind of misalignment, the
get_unaligned() accessors resolve to the leXX_to_cpup accessors that
operate on aligned addresses.

Since the compiler will in fact emit ldrd or ldm instructions when
building this code for ARM v6 or later, the solution is to use the
unaligned accessors unconditionally on architectures where this is
known to be fast. The _aligned version of the hash function is
however still needed to get the best performance on architectures
that cannot do any unaligned access in hardware.

This new version avoids the undefined behavior and should produce
the fastest hash on all architectures we support.

Link: https://lore.kernel.org/linux-arm-kernel/20181008211554.5355-4-ard.biesheuvel@linaro.org/
Link: https://lore.kernel.org/linux-crypto/CAK8P3a2KfmmGDbVHULWevB0hv71P2oi2ZCHEAqT=8dQfa0=cqQ@mail.gmail.com/
Reported-by: Ard Biesheuvel
Fixes: 2c956a60778c ("siphash: add cryptographically secure PRF")
Signed-off-by: Arnd Bergmann
Reviewed-by: Jason A. Donenfeld
Acked-by: Ard Biesheuvel
Signed-off-by: Jason A. Donenfeld
Signed-off-by: Jakub Kicinski
Signed-off-by: Greg Kroah-Hartman

fs: add fget_many() and fput_many()

2021-12-08T07:44:08+00:00

commit 091141a42e15fe47ada737f3996b317072afcefb upstream.

Some uses cases repeatedly get and put references to the same file, but
the only exposed interface is doing these one at the time. As each of
these entail an atomic inc or dec on a shared structure, that cost can
add up.

Add fget_many(), which works just like fget(), except it takes an
argument for how many references to get on the file. Ditto fput_many(),
which can drop an arbitrary number of references to a file.

Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

kprobes: Limit max data_size of the kretprobe instances

2021-12-08T07:44:07+00:00

commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream.

The 'kprobe::data_size' is unsigned, thus it can not be negative.  But if
user sets it enough big number (e.g. (size_t)-8), the result of 'data_size
+ sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct
kretprobe_instance) or zero. In result, the kretprobe_instance are
allocated without enough memory, and kretprobe accesses outside of
allocated memory.

To avoid this issue, introduce a max limitation of the
kretprobe::data_size. 4KB per instance should be OK.

Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler")
Reported-by: zhangyue 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

shm: extend forced shm destroy to support objects from several IPC nses

2021-12-08T07:44:06+00:00

commit 85b6d24646e4125c591639841169baa98a2da503 upstream.

Currently, the exit_shm() function not designed to work properly when
task->sysvshm.shm_clist holds shm objects from different IPC namespaces.

This is a real pain when sysctl kernel.shm_rmid_forced = 1, because it
leads to use-after-free (reproducer exists).

This is an attempt to fix the problem by extending exit_shm mechanism to
handle shm's destroy from several IPC ns'es.

To achieve that we do several things:

1. add a namespace (non-refcounted) pointer to the struct shmid_kernel

2. during new shm object creation (newseg()/shmget syscall) we
   initialize this pointer by current task IPC ns

3. exit_shm() fully reworked such that it traverses over all shp's in
   task->sysvshm.shm_clist and gets IPC namespace not from current task
   as it was before but from shp's object itself, then call
   shm_destroy(shp, ns).

Note: We need to be really careful here, because as it was said before
(1), our pointer to IPC ns non-refcnt'ed.  To be on the safe side we
using special helper get_ipc_ns_not_zero() which allows to get IPC ns
refcounter only if IPC ns not in the "state of destruction".

Q/A

Q: Why can we access shp->ns memory using non-refcounted pointer?
A: Because shp object lifetime is always shorther than IPC namespace
   lifetime, so, if we get shp object from the task->sysvshm.shm_clist
   while holding task_lock(task) nobody can steal our namespace.

Q: Does this patch change semantics of unshare/setns/clone syscalls?
A: No. It's just fixes non-covered case when process may leave IPC
   namespace without getting task->sysvshm.shm_clist list cleaned up.

Link: https://lkml.kernel.org/r/67bb03e5-f79c-1815-e2bf-949c67047418@colorfullife.com
Link: https://lkml.kernel.org/r/20211109151501.4921-1-manfred@colorfullife.com
Fixes: ab602f79915 ("shm: make exit_shm work proportional to task activity")
Co-developed-by: Manfred Spraul 
Signed-off-by: Manfred Spraul 
Signed-off-by: Alexander Mikhalitsyn 
Cc: "Eric W. Biederman" 
Cc: Davidlohr Bueso 
Cc: Greg KH 
Cc: Andrei Vagin 
Cc: Pavel Tikhomirov 
Cc: Vasily Averin 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

libata: fix read log timeout value

2021-11-26T10:58:33+00:00

commit 68dbbe7d5b4fde736d104cbbc9a2fce875562012 upstream.

Some ATA drives are very slow to respond to READ_LOG_EXT and
READ_LOG_DMA_EXT commands issued from ata_dev_configure() when the
device is revalidated right after resuming a system or inserting the
ATA adapter driver (e.g. ahci). The default 5s timeout
(ATA_EH_CMD_DFL_TIMEOUT) used for these commands is too short, causing
errors during the device configuration. Ex:

...
ata9: SATA max UDMA/133 abar m524288@0x9d200000 port 0x9d200400 irq 209
ata9: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata9.00: ATA-9: XXX  XXXXXXXXXXXXXXX, XXXXXXXX, max UDMA/133
ata9.00: qc timeout (cmd 0x2f)
ata9.00: Read log page 0x00 failed, Emask 0x4
ata9.00: Read log page 0x00 failed, Emask 0x40
ata9.00: NCQ Send/Recv Log not supported
ata9.00: Read log page 0x08 failed, Emask 0x40
ata9.00: 27344764928 sectors, multi 16: LBA48 NCQ (depth 32), AA
ata9.00: Read log page 0x00 failed, Emask 0x40
ata9.00: ATA Identify Device Log not supported
ata9.00: failed to set xfermode (err_mask=0x40)
ata9: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata9.00: configured for UDMA/133
...

The timeout error causes a soft reset of the drive link, followed in
most cases by a successful revalidation as that give enough time to the
drive to become fully ready to quickly process the read log commands.
However, in some cases, this also fails resulting in the device being
dropped.

Fix this by using adding the ata_eh_revalidate_timeouts entries for the
READ_LOG_EXT and READ_LOG_DMA_EXT commands. This defines a timeout
increased to 15s, retriable one time.

Reported-by: Geert Uytterhoeven 
Tested-by: Geert Uytterhoeven 
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Signed-off-by: Greg Kroah-Hartman

binder: use cred instead of task for selinux checks

2021-11-26T10:58:33+00:00

commit 52f88693378a58094c538662ba652aff0253c4fe upstream.

Since binder was integrated with selinux, it has passed
'struct task_struct' associated with the binder_proc
to represent the source and target of transactions.
The conversion of task to SID was then done in the hook
implementations. It turns out that there are race conditions
which can result in an incorrect security context being used.

Fix by using the 'struct cred' saved during binder_open and pass
it to the selinux subsystem.

Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables)
Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.")
Suggested-by: Jann Horn 
Signed-off-by: Todd Kjos 
Acked-by: Casey Schaufler 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

elfcore: correct reference to CONFIG_UML

2021-10-27T07:32:39+00:00

commit b0e901280d9860a0a35055f220e8e457f300f40a upstream.

Commit 6e7b64b9dd6d ("elfcore: fix building with clang") introduces
special handling for two architectures, ia64 and User Mode Linux.
However, the wrong name, i.e., CONFIG_UM, for the intended Kconfig
symbol for User-Mode Linux was used.

Although the directory for User Mode Linux is ./arch/um; the Kconfig
symbol for this architecture is called CONFIG_UML.

Luckily, ./scripts/checkkconfigsymbols.py warns on non-existing configs:

  UM
  Referencing files: include/linux/elfcore.h
  Similar symbols: UML, NUMA

Correct the name of the config to the intended one.

[akpm@linux-foundation.org: fix um/x86_64, per Catalin]
  Link: https://lkml.kernel.org/r/20211006181119.2851441-1-catalin.marinas@arm.com
  Link: https://lkml.kernel.org/r/YV6pejGzLy5ppEpt@arm.com

Link: https://lkml.kernel.org/r/20211006082209.417-1-lukas.bulwahn@gmail.com
Fixes: 6e7b64b9dd6d ("elfcore: fix building with clang")
Signed-off-by: Lukas Bulwahn 
Cc: Arnd Bergmann 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Catalin Marinas 
Cc: Barret Rhoden 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

libata: Add ATA_HORKAGE_NO_NCQ_ON_ATI for Samsung 860 and 870 SSD.

2021-10-09T11:24:30+00:00

commit 7a8526a5cd51cf5f070310c6c37dd7293334ac49 upstream.

Many users are reporting that the Samsung 860 and 870 SSD are having
various issues when combined with AMD/ATI (vendor ID 0x1002)  SATA
controllers and only completely disabling NCQ helps to avoid these
issues.

Always disabling NCQ for Samsung 860/870 SSDs regardless of the host
SATA adapter vendor will cause I/O performance degradation with well
behaved adapters. To limit the performance impact to ATI adapters,
introduce the ATA_HORKAGE_NO_NCQ_ON_ATI flag to force disable NCQ
only for these adapters.

Also, two libata.force parameters (noncqati and ncqati) are introduced
to disable and enable the NCQ for the system which equipped with ATI
SATA adapter and Samsung 860 and 870 SSDs. The user can determine NCQ
function to be enabled or disabled according to the demand.

After verifying the chipset from the user reports, the issue appears
on AMD/ATI SB7x0/SB8x0/SB9x0 SATA Controllers and does not appear on
recent AMD SATA adapters. The vendor ID of ATI should be 0x1002.
Therefore, ATA_HORKAGE_NO_NCQ_ON_AMD was modified to
ATA_HORKAGE_NO_NCQ_ON_ATI.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=201693
Signed-off-by: Kate Hsuan 
Reviewed-by: Hans de Goede 
Link: https://lore.kernel.org/r/20210903094411.58749-1-hpa@redhat.com
Reviewed-by: Martin K. Petersen 
Signed-off-by: Jens Axboe 
Cc: Krzysztof Olędzki 
Signed-off-by: Greg Kroah-Hartman

cred: allow get_cred() and put_cred() to be given NULL.

2021-10-06T08:22:25+00:00

commit f06bc03339ad4c1baa964a5f0606247ac1c3c50b upstream.

It is common practice for helpers like this to silently,
accept a NULL pointer.
get_rpccred() and put_rpccred() used by NFS act this way
and using the same interface will ease the conversion
for NFS, and simplify the resulting code.

Signed-off-by: NeilBrown 
Signed-off-by: Anna Schumaker 
Cc: Eric Dumazet 
Signed-off-by: Greg Kroah-Hartman

compiler.h: Introduce absolute_pointer macro

2021-10-06T08:22:23+00:00

[ Upstream commit f6b5f1a56987de837f8e25cd560847106b8632a8 ]

absolute_pointer() disassociates a pointer from its originating symbol
type and context. Use it to prevent compiler warnings/errors such as

  drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
  arch/m68k/include/asm/string.h:72:25: error:
	'__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]

Such warnings may be reported by gcc 11.x for string and memory
operations on fixed addresses.

Suggested-by: Linus Torvalds 
Signed-off-by: Guenter Roeck 
Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin