The kbuild test robot reported the following warning:
arch/sparc/mm/srmmu.c: In function 'srmmu_nocache_init': arch/sparc/mm/srmmu.c:300:9: error: variable 'pud' set but not used [-Werror=unused-but-set-variable]
300 | pud_t *pud;
This warning is caused by misprint in the page table traversal in
srmmu_nocache_init() function which accessed a PMD entry using PGD
rather than PUD.
Since sparc32 has only 3 page table levels, the PGD and PUD are
essentially the same and usage of __nocache_fix() removed the type
checking.
Use PUD for the consistency and to silence the compiler warning.
Fixes: 7235db268a ("sparc32: use pgtable-nopud instead of 4level-fixup")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200520132005.GM1059226@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Assume we have kmem configured and loaded:
[root@localhost ~]# cat /proc/iomem
...
140000000-33fffffff : Persistent Memory$
140000000-1481fffff : namespace0.0
150000000-33fffffff : dax0.0
150000000-33fffffff : System RAM
Assume we try to unload kmem. This force-unloading will work, even if
memory cannot get removed from the system.
[root@localhost ~]# rmmod kmem
[ 86.380228] removing memory fails, because memory [0x0000000150000000-0x0000000157ffffff] is onlined
...
[ 86.431225] kmem dax0.0: DAX region [mem 0x150000000-0x33fffffff] cannot be hotremoved until the next reboot
Now, we can reconfigure the namespace:
[root@localhost ~]# ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax
[ 131.409351] nd_pmem namespace0.0: could not reserve region [mem 0x140000000-0x33fffffff]dax
[ 131.410147] nd_pmem: probe of namespace0.0 failed with error -16namespace0.0 --mode=devdax
...
This fails as expected due to the busy memory resource, and the memory
cannot be used. However, the dax0.0 device is removed, and along its
name.
The name of the memory resource now points at freed memory (name of the
device):
[root@localhost ~]# cat /proc/iomem
...
140000000-33fffffff : Persistent Memory
140000000-1481fffff : namespace0.0
150000000-33fffffff : �_�^7_��/_��wR��WQ���^��� ...
150000000-33fffffff : System RAM
We have to make sure to duplicate the string. While at it, remove the
superfluous setting of the name and fixup a stale comment.
Fixes: 9f960da72b ("device-dax: "Hotremove" persistent memory that is used like normal RAM")
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org> [5.3]
Link: http://lkml.kernel.org/r/20200508084217.9160-2-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull io_uring fixes from Jens Axboe:
"A small collection of small fixes that should go into this release:
- Two fixes for async request preparation (Pavel)
- Busy clear fix for SQPOLL (Xiaoguang)
- Don't use kiocb->private for O_DIRECT buf index, some file systems
use it (Bijan)
- Kill dead check in io_splice()
- Ensure sqo_wait is initialized early
- Cancel task_work if we fail adding to original process
- Only add (IO)pollable requests to iopoll list, fixing a regression
in this merge window"
* tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block:
io_uring: reset -EBUSY error when io sq thread is waken up
io_uring: don't add non-IO requests to iopoll pending list
io_uring: don't use kiocb.private to store buf_index
io_uring: cancel work if task_work_add() fails
io_uring: remove dead check in io_splice()
io_uring: fix FORCE_ASYNC req preparation
io_uring: don't prepare DRAIN reqs twice
io_uring: initialize ctx->sqo_wait earlier
Pull block fixes from Jens Axboe:
"Two fixes for null_blk zone mode"
* tag 'block-5.7-2020-05-22' of git://git.kernel.dk/linux-block:
null_blk: don't allow discard for zoned mode
null_blk: return error for invalid zone size
Pull RISC-V fixes from Palmer Dabbelt:
"Two fixes:
- Another !MMU build fix that was a straggler from last week
- A fix to use the "register" keyword for the GP global register
variable"
* tag 'riscv-for-linus-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
RISC-V: gp_in_global needs register keyword
riscv: Fix print_vm_layout build error if NOMMU
Pull arm64 fixes from Catalin Marinas:
- Bring the PTRACE_SYSEMU semantics in line with the man page.
- Annotate variable assignment in get_user() with the type to avoid
sparse warnings.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Add get_user() type annotation on the !access_ok() path
arm64: Fix PTRACE_SYSEMU semantics
Pull sound fixes from Takashi Iwai:
"Just a few small fixes: the only significant one is a slight
improvement for PCM running position update with no-period-elapsed
case while the rest are HD-audio fixups and ice1712 model quirk"
* tag 'sound-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda/realtek - Add more fixup entries for Clevo machines
ALSA: iec1712: Initialize STDSP24 properly when using the model=staudio option
ALSA: hda/realtek - Fix silent output on Gigabyte X570 Aorus Xtreme
ALSA: pcm: fix incorrect hw_base increase
Pull powerpc fixes from Michael Ellerman:
- a revert of a recent change to the PTE bits for 32-bit BookS, which
broke swap.
- a "fix" to disable STRICT_KERNEL_RWX for 64-bit in Kconfig, as it's
causing crashes for some people.
Thanks to Christophe Leroy and Rui Salvaterra.
* tag 'powerpc-5.7-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s: Disable STRICT_KERNEL_RWX
Revert "powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits."
As Ubuntu and Fedora release new version used kernel version equal to or
higher than v5.4, They started to support kernel exfat filesystem.
Linus reported a mount error with new version of exfat on Fedora:
exfat: Unknown parameter 'namecase'
This is because there is a difference in mount option between old
staging/exfat and new exfat. And utf8, debug, and codepage options as
well as namecase have been removed from new exfat.
This patch add the dummy mount options as deprecated option to be
backward compatible with old one.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the implementation of aa_audit_rule_init(), when aa_label_parse()
fails the allocated memory for rule is released using
aa_audit_rule_free(). But after this release, the return statement
tries to access the label field of the rule which results in
use-after-free. Before releasing the rule, copy errNo and return it
after release.
Fixes: 52e8c38001 ("apparmor: Fix memory leak of rule on error exit path")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
policy_update() invokes begin_current_label_crit_section(), which
returns a reference of the updated aa_label object to "label" with
increased refcount.
When policy_update() returns, "label" becomes invalid, so the refcount
should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
policy_update(). When aa_may_manage_policy() returns not NULL, the
refcnt increased by begin_current_label_crit_section() is not decreased,
causing a refcnt leak.
Fix this issue by jumping to "end_section" label when
aa_may_manage_policy() returns not NULL.
Fixes: 5ac8c355ae ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
aa_change_profile() invokes aa_get_current_label(), which returns
a reference of the current task's label.
According to the comment of aa_get_current_label(), the returned
reference must be put with aa_put_label().
However, when the original object pointed by "label" becomes
unreachable because aa_change_profile() returns or a new object
is assigned to "label", reference count increased by
aa_get_current_label() is not decreased, causing a refcnt leak.
Fix this by calling aa_put_label() before aa_change_profile() return
and dropping unnecessary aa_get_current_label().
Fixes: 9fcf78cca1 ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
The Intel kernel build robot recently pointed out that I missed the
register keyword on this one when I refactored the code to remove local
register variables (which aren't supported by LLVM). GCC's manual
indicates that global register variables must have the register keyword,
As far as I can tell lacking the register keyword causes GCC to ignore
the __asm__ and treat this as a regular variable, but I'm not sure how
that didn't show up as some sort of failure.
Fixes: 52e7c52d2d ("RISC-V: Stop relying on GCC's register allocator's hueristics")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Pull virtio fixes from Michael Tsirkin:
"Fix a couple of build warnings"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: missing __user tags
vdpasim: remove unused variable 'ret'
Zoned block device specification do not define the behavior of
discard/trim command as this command is generally replaced by the reset
write pointer (zone reset) command. Emulate this in null_blk by making
zoned and discard options mutually exclusive.
Suggested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.
Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.
Although fixes for those are in development, they're not -rc material.
There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.
So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.
Fixes: 1e0fc9d1eb ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au
arch/riscv/mm/init.c: In function ‘print_vm_layout’:
arch/riscv/mm/init.c:68:37: error: ‘FIXADDR_START’ undeclared (first use in this function);
arch/riscv/mm/init.c:69:20: error: ‘FIXADDR_TOP’ undeclared
arch/riscv/mm/init.c:70:37: error: ‘PCI_IO_START’ undeclared
arch/riscv/mm/init.c:71:20: error: ‘PCI_IO_END’ undeclared
arch/riscv/mm/init.c:72:38: error: ‘VMEMMAP_START’ undeclared
arch/riscv/mm/init.c:73:20: error: ‘VMEMMAP_END’ undeclared (first use in this function);
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Pull MTD fixes from Richard Weinberger:
- Fix a PM regression in brcmnand driver
- Propagate ECC information correctly on SPI-NAND
- Make sure no MTD name is used multiple time in nvmem
* tag 'fixes-for-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
mtd:rawnand: brcmnand: Fix PM resume crash
mtd: Fix mtd not registered due to nvmem name collision
mtd: spinand: Propagate ECC information to the MTD structure
Pull UBI and UBIFS fixes from Richard Weinberger:
- Correctly set next cursor for detailed_erase_block_info debugfs file
- Don't use crypto_shash_descsize() for digest size in UBIFS
- Remove broken lazytime support from UBIFS
* tag 'for-linus-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
ubi: Fix seq_file usage in detailed_erase_block_info debugfs file
ubifs: fix wrong use of crypto_shash_descsize()
ubifs: remove broken lazytime support
Pull UML fixes from Richard Weinberger:
- Two missing includes which caused build issues on recent systems
- Correctly set TRANS_GRE_LEN in our vector network driver
* tag 'for-linus-5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Fix typo in vector driver transport option definition
um: syscall.c: include <asm/unistd.h>
um: Fix xor.h include
Pull power management fix from Rafael Wysocki:
"This makes a recently introduced suspend-to-idle wakeup issue on Dell
XPS13 9360 go away"
* tag 'pm-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: EC: PM: Avoid flushing EC work when EC GPE is inactive
Pull overlayfs fixes from Miklos Szeredi:
"Fix two bugs introduced in this cycle and one introduced in v5.5"
* tag 'ovl-fixes-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: potential crash in ovl_fid_to_fh()
ovl: clear ATTR_OPEN from attr->ia_valid
ovl: clear ATTR_FILE from attr->ia_valid
In io_sq_thread(), currently if we get an -EBUSY error and go to sleep,
we will won't clear it again, which will result in io_sq_thread() will
never have a chance to submit sqes again. Below test program test.c
can reveal this bug:
int main(int argc, char *argv[])
{
struct io_uring ring;
int i, fd, ret;
struct io_uring_sqe *sqe;
struct io_uring_cqe *cqe;
struct iovec *iovecs;
void *buf;
struct io_uring_params p;
if (argc < 2) {
printf("%s: file\n", argv[0]);
return 1;
}
memset(&p, 0, sizeof(p));
p.flags = IORING_SETUP_SQPOLL;
ret = io_uring_queue_init_params(4, &ring, &p);
if (ret < 0) {
fprintf(stderr, "queue_init: %s\n", strerror(-ret));
return 1;
}
fd = open(argv[1], O_RDONLY | O_DIRECT);
if (fd < 0) {
perror("open");
return 1;
}
iovecs = calloc(10, sizeof(struct iovec));
for (i = 0; i < 10; i++) {
if (posix_memalign(&buf, 4096, 4096))
return 1;
iovecs[i].iov_base = buf;
iovecs[i].iov_len = 4096;
}
ret = io_uring_register_files(&ring, &fd, 1);
if (ret < 0) {
fprintf(stderr, "%s: register %d\n", __FUNCTION__, ret);
return ret;
}
for (i = 0; i < 10; i++) {
sqe = io_uring_get_sqe(&ring);
if (!sqe)
break;
io_uring_prep_readv(sqe, 0, &iovecs[i], 1, 0);
sqe->flags |= IOSQE_FIXED_FILE;
ret = io_uring_submit(&ring);
sleep(1);
printf("submit %d\n", i);
}
for (i = 0; i < 10; i++) {
io_uring_wait_cqe(&ring, &cqe);
printf("receive: %d\n", i);
if (cqe->res != 4096) {
fprintf(stderr, "ret=%d, wanted 4096\n", cqe->res);
ret = 1;
}
io_uring_cqe_seen(&ring, cqe);
}
close(fd);
io_uring_queue_exit(&ring);
return 0;
}
sudo ./test testfile
above command will hang on the tenth request, to fix this bug, when io
sq_thread is waken up, we reset the variable 'ret' to be zero.
Suggested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Quoth the man page:
```
If the tracee was restarted by PTRACE_SYSCALL or PTRACE_SYSEMU, the
tracee enters syscall-enter-stop just prior to entering any system
call (which will not be executed if the restart was using
PTRACE_SYSEMU, regardless of any change made to registers at this
point or how the tracee is restarted after this stop).
```
The parenthetical comment is currently true on x86 and powerpc,
but not currently true on arm64. arm64 re-checks the _TIF_SYSCALL_EMU
flag after the syscall entry ptrace stop. However, at this point,
it reflects which method was used to re-start the syscall
at the entry stop, rather than the method that was used to reach it.
Fix that by recording the original flag before performing the ptrace
stop, bringing the behavior in line with documentation and x86/powerpc.
Fixes: f086f67485 ("arm64: ptrace: add support for syscall emulation")
Cc: <stable@vger.kernel.org> # 5.3.x-
Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Will Deacon <will@kernel.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Bin Lu <Bin.Lu@arm.com>
[catalin.marinas@arm.com: moved 'flags' bit masking]
[catalin.marinas@arm.com: changed 'flags' type to unsigned long]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We normally disable any commands that aren't specifically poll commands
for a ring that is setup for polling, but we do allow buffer provide and
remove commands to support buffer selection for polled IO. Once a
request is issued, we add it to the poll list to poll for completion. But
we should not do that for non-IO commands, as those request complete
inline immediately and aren't pollable. If we do, we can leave requests
on the iopoll list after they are freed.
Fixes: ddf0322db7 ("io_uring: add IORING_OP_PROVIDE_BUFFERS")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull vfs fix from Al Viro:
"Stable fodder fix: copy_fdtable() would get screwed on 64bit boxen
with sysctl_nr_open raised to 512M or higher, which became possible
since 2.6.25.
Nobody sane would set the things up that way, but..."
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix multiplication overflow in copy_fdtable()
Pull ARC fixes from Vineet Gupta:
- fix recent DSP code regression on ARC700 platforms
- fix thinkos in ICCM/DCCM size checks
- USB regression fix
- other small fixes here and there
* tag 'arc-5.7-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: show_regs: avoid extra line of output
ARC: guard dsp early init against non ARCv2
ARC: [plat-eznps]: Restrict to CONFIG_ISA_ARCOMPACT
ARC: entry: comment
arc: remove #ifndef CONFIG_AS_CFI_SIGNAL_FRAME
arc: ptrace: hard-code "arc" instead of UTS_MACHINE
ARC: [plat-hsdk]: fix USB regression
ARC: Fix ICCM & DCCM runtime size checks
cpy and set really should be size_t; we won't get an overflow on that,
since sysctl_nr_open can't be set above ~(size_t)0 / sizeof(void *),
so nr that would've managed to overflow size_t on that multiplication
won't get anywhere near copy_fdtable() - we'll fail with EMFILE
before that.
Cc: stable@kernel.org # v2.6.25+
Fixes: 9cfe015aa4 (get rid of NR_OPEN and introduce a sysctl_nr_open)
Reported-by: Thiago Macieira <thiago.macieira@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
kiocb.private is used in iomap_dio_rw() so store buf_index separately.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Move 'buf_index' to a hole in io_kiocb.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add an extra validation of the len parameter, as for ext4 some files
might have smaller file size limits than others. This also means the
redundant size check in ext4_ioctl_get_es_cache can go away, as all
size checking is done in the shared fiemap handler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200505154324.3226743-3-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4 supports max number of logical blocks in a file to be 0xffffffff.
(This is since ext4_extent's ee_block is __le32).
This means that EXT4_MAX_LOGICAL_BLOCK should be 0xfffffffe (starting
from 0 logical offset). This patch fixes this.
The issue was seen when ext4 moved to iomap_fiemap API and when
overlayfs was mounted on top of ext4. Since overlayfs was missing
filemap_check_ranges(), so it could pass a arbitrary huge length which
lead to overflow of map.m_len logic.
This patch fixes that.
Fixes: d3b6f23f71 ("ext4: move ext4_fiemap to use iomap framework")
Reported-by: syzbot+77fa5bdb65cc39711820@syzkaller.appspotmail.com
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200505154324.3226743-2-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Pull i2c fixes from Wolfram Sang:
"A set of driver and core fixes as well as MAINTAINER update"
* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
MAINTAINERS: add maintainer for mediatek i2c controller driver
i2c: mux: Replace zero-length array with flexible-array
i2c: mux: demux-pinctrl: Fix an error handling path in 'i2c_demux_pinctrl_probe()'
i2c: altera: Fix race between xfer_msg and isr thread
i2c: algo-pca: update contact email
i2c: at91: Fix pinmux after devm_gpiod_get() for bus recovery
i2c: use my kernel.org address from now on
i2c: fix missing pm_runtime_put_sync in i2c_device_probe
Pull hyperv fix from Wei Liu:
"One patch from Vitaly to fix reenlightenment notifications"
* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
x86/hyperv: Properly suspend/resume reenlightenment notifications
Pull iommu fixes from Joerg Roedel:
"All related to the AMD IOMMU driver:
- ACPI table parser fix to correctly read the UID of ACPI devices
- ACPI UID device matching fix
- Fix deferred device attachment to a domain in kdump kernels when
the IOMMU driver uses the dma-iommu DMA-API implementation"
* tag 'iommu-fixes-v5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu: Fix deferred domain attachment
iommu/amd: Fix get_acpihid_device_id()
iommu/amd: Fix over-read of ACPI UID from IVRS table
I don't see what security concern is addressed by obfuscating NULL
and IS_ERR() error pointers, printed with %p/%pK. Given the number
of sites where %p is used (over 10000) and the fact that NULL pointers
aren't uncommon, it probably wouldn't take long for an attacker to
find the hash that corresponds to 0. Although harder, the same goes
for most common error values, such as -1, -2, -11, -14, etc.
The NULL part actually fixes a regression: NULL pointers weren't
obfuscated until commit 3e5903eb9c ("vsprintf: Prevent crash when
dereferencing invalid pointers") which went into 5.2. I'm tacking
the IS_ERR() part on here because error pointers won't leak kernel
addresses and printing them as pointers shouldn't be any different
from e.g. %d with PTR_ERR_OR_ZERO(). Obfuscating them just makes
debugging based on existing pr_debug and friends excruciating.
Note that the "always print 0's for %pK when kptr_restrict == 2"
behaviour which goes way back is left as is.
Example output with the patch applied:
ptr error-ptr NULL
%p: 0000000001f8cc5b fffffffffffffff2 0000000000000000
%pK, kptr = 0: 0000000001f8cc5b fffffffffffffff2 0000000000000000
%px: ffff888048c04020 fffffffffffffff2 0000000000000000
%pK, kptr = 1: ffff888048c04020 fffffffffffffff2 0000000000000000
%pK, kptr = 2: 0000000000000000 0000000000000000 0000000000000000
Fixes: 3e5903eb9c ("vsprintf: Prevent crash when dereferencing invalid pointers")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
