Linux: >> Linux Kernel >> 6.1.49 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
udf: refactor inode_bmap() to handle error
Refactor inode_bmap() to handle error since udf_next_aext() can return
error now. On situations like ftruncate, udf_extend_file() can now
detect errors and bail out early without resorting to checking for
particular offsets and assuming internal behavior of these functions.
CVSS Score
3.3
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
ext4: don't set SB_RDONLY after filesystem errors
When the filesystem is mounted with errors=remount-ro, we were setting
SB_RDONLY flag to stop all filesystem modifications. We knew this misses
proper locking (sb->s_umount) and does not go through proper filesystem
remount procedure but it has been the way this worked since early ext2
days and it was good enough for catastrophic situation damage
mitigation. Recently, syzbot has found a way (see link) to trigger
warnings in filesystem freezing because the code got confused by
SB_RDONLY changing under its hands. Since these days we set
EXT4_FLAGS_SHUTDOWN on the superblock which is enough to stop all
filesystem modifications, modifying SB_RDONLY shouldn't be needed. So
stop doing that.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
irqchip/gic-v4: Don't allow a VMOVP on a dying VPE
Kunkun Jiang reported that there is a small window of opportunity for
userspace to force a change of affinity for a VPE while the VPE has already
been unmapped, but the corresponding doorbell interrupt still visible in
/proc/irq/.
Plug the race by checking the value of vmapp_count, which tracks whether
the VPE is mapped ot not, and returning an error in this case.
This involves making vmapp_count common to both GICv4.1 and its v4.0
ancestor.
CVSS Score
4.7
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
x86/entry_32: Clear CPU buffers after register restore in NMI return
CPU buffers are currently cleared after call to exc_nmi, but before
register state is restored. This may be okay for MDS mitigation but not for
RDFS. Because RDFS mitigation requires CPU buffers to be cleared when
registers don't have any sensitive data.
Move CLEAR_CPU_BUFFERS after RESTORE_ALL_NMI.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
arm64: probes: Fix uprobes for big-endian kernels
The arm64 uprobes code is broken for big-endian kernels as it doesn't
convert the in-memory instruction encoding (which is always
little-endian) into the kernel's native endianness before analyzing and
simulating instructions. This may result in a few distinct problems:
* The kernel may may erroneously reject probing an instruction which can
safely be probed.
* The kernel may erroneously erroneously permit stepping an
instruction out-of-line when that instruction cannot be stepped
out-of-line safely.
* The kernel may erroneously simulate instruction incorrectly dur to
interpretting the byte-swapped encoding.
The endianness mismatch isn't caught by the compiler or sparse because:
* The arch_uprobe::{insn,ixol} fields are encoded as arrays of u8, so
the compiler and sparse have no idea these contain a little-endian
32-bit value. The core uprobes code populates these with a memcpy()
which similarly does not handle endianness.
* While the uprobe_opcode_t type is an alias for __le32, both
arch_uprobe_analyze_insn() and arch_uprobe_skip_sstep() cast from u8[]
to the similarly-named probe_opcode_t, which is an alias for u32.
Hence there is no endianness conversion warning.
Fix this by changing the arch_uprobe::{insn,ixol} fields to __le32 and
adding the appropriate __le32_to_cpu() conversions prior to consuming
the instruction encoding. The core uprobes copies these fields as opaque
ranges of bytes, and so is unaffected by this change.
At the same time, remove MAX_UINSN_BYTES and consistently use
AARCH64_INSN_SIZE for clarity.
Tested with the following:
| #include <stdio.h>
| #include <stdbool.h>
|
| #define noinline __attribute__((noinline))
|
| static noinline void *adrp_self(void)
| {
| void *addr;
|
| asm volatile(
| " adrp %x0, adrp_self\n"
| " add %x0, %x0, :lo12:adrp_self\n"
| : "=r" (addr));
| }
|
|
| int main(int argc, char *argv)
| {
| void *ptr = adrp_self();
| bool equal = (ptr == adrp_self);
|
| printf("adrp_self => %p\n"
| "adrp_self() => %p\n"
| "%s\n",
| adrp_self, ptr, equal ? "EQUAL" : "NOT EQUAL");
|
| return 0;
| }
.... where the adrp_self() function was compiled to:
| 00000000004007e0 <adrp_self>:
| 4007e0: 90000000 adrp x0, 400000 <__ehdr_start>
| 4007e4: 911f8000 add x0, x0, #0x7e0
| 4007e8: d65f03c0 ret
Before this patch, the ADRP is not recognized, and is assumed to be
steppable, resulting in corruption of the result:
| # ./adrp-self
| adrp_self => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL
| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events
| # echo 1 > /sys/kernel/tracing/events/uprobes/enable
| # ./adrp-self
| adrp_self => 0x4007e0
| adrp_self() => 0xffffffffff7e0
| NOT EQUAL
After this patch, the ADRP is correctly recognized and simulated:
| # ./adrp-self
| adrp_self => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL
| #
| # echo 'p /root/adrp-self:0x007e0' > /sys/kernel/tracing/uprobe_events
| # echo 1 > /sys/kernel/tracing/events/uprobes/enable
| # ./adrp-self
| adrp_self => 0x4007e0
| adrp_self() => 0x4007e0
| EQUAL
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
posix-clock: Fix missing timespec64 check in pc_clock_settime()
As Andrew pointed out, it will make sense that the PTP core
checked timespec64 struct's tv_sec and tv_nsec range before calling
ptp->info->settime64().
As the man manual of clock_settime() said, if tp.tv_sec is negative or
tp.tv_nsec is outside the range [0..999,999,999], it should return EINVAL,
which include dynamic clocks which handles PTP clock, and the condition is
consistent with timespec64_valid(). As Thomas suggested, timespec64_valid()
only check the timespec is valid, but not ensure that the time is
in a valid range, so check it ahead using timespec64_valid_strict()
in pc_clock_settime() and return -EINVAL if not valid.
There are some drivers that use tp->tv_sec and tp->tv_nsec directly to
write registers without validity checks and assume that the higher layer
has checked it, which is dangerous and will benefit from this, such as
hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(),
and some drivers can remove the checks of itself.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: ocelot: fix system hang on level based interrupts
The current implementation only calls chained_irq_enter() and
chained_irq_exit() if it detects pending interrupts.
```
for (i = 0; i < info->stride; i++) {
uregmap_read(info->map, id_reg + 4 * i, ®);
if (!reg)
continue;
chained_irq_enter(parent_chip, desc);
```
However, in case of GPIO pin configured in level mode and the parent
controller configured in edge mode, GPIO interrupt might be lowered by the
hardware. In the result, if the interrupt is short enough, the parent
interrupt is still pending while the GPIO interrupt is cleared;
chained_irq_enter() never gets called and the system hangs trying to
service the parent interrupt.
Moving chained_irq_enter() and chained_irq_exit() outside the for loop
ensures that they are called even when GPIO interrupt is lowered by the
hardware.
The similar code with chained_irq_enter() / chained_irq_exit() functions
wrapping interrupt checking loop may be found in many other drivers:
```
grep -r -A 10 chained_irq_enter drivers/pinctrl
```
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
iio: light: veml6030: fix IIO device retrieval from embedded device
The dev pointer that is received as an argument in the
in_illuminance_period_available_show function references the device
embedded in the IIO device, not in the i2c client.
dev_to_iio_dev() must be used to accessthe right data. The current
implementation leads to a segmentation fault on every attempt to read
the attribute because indio_dev gets a NULL assignment.
This bug has been present since the first appearance of the driver,
apparently since the last version (V6) before getting applied. A
constant attribute was used until then, and the last modifications might
have not been tested again.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
mm/swapfile: skip HugeTLB pages for unuse_vma
I got a bad pud error and lost a 1GB HugeTLB when calling swapoff. The
problem can be reproduced by the following steps:
1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory.
2. Swapout the above anonymous memory.
3. run swapoff and we will get a bad pud error in kernel message:
mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)
We can tell that pud_clear_bad is called by pud_none_or_clear_bad in
unuse_pud_range() by ftrace. And therefore the HugeTLB pages will never
be freed because we lost it from page table. We can skip HugeTLB pages
for unuse_vma to fix it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
maple_tree: correct tree corruption on spanning store
Patch series "maple_tree: correct tree corruption on spanning store", v3.
There has been a nasty yet subtle maple tree corruption bug that appears
to have been in existence since the inception of the algorithm.
This bug seems far more likely to happen since commit f8d112a4e657
("mm/mmap: avoid zeroing vma tree in mmap_region()"), which is the point
at which reports started to be submitted concerning this bug.
We were made definitely aware of the bug thanks to the kind efforts of
Bert Karwatzki who helped enormously in my being able to track this down
and identify the cause of it.
The bug arises when an attempt is made to perform a spanning store across
two leaf nodes, where the right leaf node is the rightmost child of the
shared parent, AND the store completely consumes the right-mode node.
This results in mas_wr_spanning_store() mitakenly duplicating the new and
existing entries at the maximum pivot within the range, and thus maple
tree corruption.
The fix patch corrects this by detecting this scenario and disallowing the
mistaken duplicate copy.
The fix patch commit message goes into great detail as to how this occurs.
This series also includes a test which reliably reproduces the issue, and
asserts that the fix works correctly.
Bert has kindly tested the fix and confirmed it resolved his issues. Also
Mikhail Gavrilov kindly reported what appears to be precisely the same
bug, which this fix should also resolve.
This patch (of 2):
There has been a subtle bug present in the maple tree implementation from
its inception.
This arises from how stores are performed - when a store occurs, it will
overwrite overlapping ranges and adjust the tree as necessary to
accommodate this.
A range may always ultimately span two leaf nodes. In this instance we
walk the two leaf nodes, determine which elements are not overwritten to
the left and to the right of the start and end of the ranges respectively
and then rebalance the tree to contain these entries and the newly
inserted one.
This kind of store is dubbed a 'spanning store' and is implemented by
mas_wr_spanning_store().
In order to reach this stage, mas_store_gfp() invokes
mas_wr_preallocate(), mas_wr_store_type() and mas_wr_walk() in turn to
walk the tree and update the object (mas) to traverse to the location
where the write should be performed, determining its store type.
When a spanning store is required, this function returns false stopping at
the parent node which contains the target range, and mas_wr_store_type()
marks the mas->store_type as wr_spanning_store to denote this fact.
When we go to perform the store in mas_wr_spanning_store(), we first
determine the elements AFTER the END of the range we wish to store (that
is, to the right of the entry to be inserted) - we do this by walking to
the NEXT pivot in the tree (i.e. r_mas.last + 1), starting at the node we
have just determined contains the range over which we intend to write.
We then turn our attention to the entries to the left of the entry we are
inserting, whose state is represented by l_mas, and copy these into a 'big
node', which is a special node which contains enough slots to contain two
leaf node's worth of data.
We then copy the entry we wish to store immediately after this - the copy
and the insertion of the new entry is performed by mas_store_b_node().
After this we copy the elements to the right of the end of the range which
we are inserting, if we have not exceeded the length of the node (i.e.
r_mas.offset <= r_mas.end).
Herein lies the bug - under very specific circumstances, this logic can
break and corrupt the maple tree.
Consider the following tree:
Height
0 Root Node
/ \
pivot = 0xffff / \ pivot = ULONG_MAX
/
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-08