Linux: >> Linux Kernel >> 4.14.101 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
0.002
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
0.002
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
0.002
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
0.002
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
0.002
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
0.002
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
0.002
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: propagate directory read errors from nilfs_find_entry()
Syzbot reported that a task hang occurs in vcs_open() during a fuzzing
test for nilfs2.
The root cause of this problem is that in nilfs_find_entry(), which
searches for directory entries, ignores errors when loading a directory
page/folio via nilfs_get_folio() fails.
If the filesystem images is corrupted, and the i_size of the directory
inode is large, and the directory page/folio is successfully read but
fails the sanity check, for example when it is zero-filled,
nilfs_check_folio() may continue to spit out error messages in bursts.
Fix this issue by propagating the error to the callers when loading a
page/folio fails in nilfs_find_entry().
The current interface of nilfs_find_entry() and its callers is outdated
and cannot propagate error codes such as -EIO and -ENOMEM returned via
nilfs_find_entry(), so fix it together.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: fix a UBSAN warning in DML2.1
When programming phantom pipe, since cursor_width is explicity set to 0,
this causes calculation logic to trigger overflow for an unsigned int
triggering the kernel's UBSAN check as below:
[ 40.962845] UBSAN: shift-out-of-bounds in /tmp/amd.EfpumTkO/amd/amdgpu/../display/dc/dml2/dml21/src/dml2_core/dml2_core_dcn4_calcs.c:3312:34
[ 40.962849] shift exponent 4294967170 is too large for 32-bit type 'unsigned int'
[ 40.962852] CPU: 1 PID: 1670 Comm: gnome-shell Tainted: G W OE 6.5.0-41-generic #41~22.04.2-Ubuntu
[ 40.962854] Hardware name: Gigabyte Technology Co., Ltd. X670E AORUS PRO X/X670E AORUS PRO X, BIOS F21 01/10/2024
[ 40.962856] Call Trace:
[ 40.962857] <TASK>
[ 40.962860] dump_stack_lvl+0x48/0x70
[ 40.962870] dump_stack+0x10/0x20
[ 40.962872] __ubsan_handle_shift_out_of_bounds+0x1ac/0x360
[ 40.962878] calculate_cursor_req_attributes.cold+0x1b/0x28 [amdgpu]
[ 40.963099] dml_core_mode_support+0x6b91/0x16bc0 [amdgpu]
[ 40.963327] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963331] ? CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport+0x18b8/0x2790 [amdgpu]
[ 40.963534] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963536] ? dml_core_mode_support+0xb3db/0x16bc0 [amdgpu]
[ 40.963730] dml2_core_calcs_mode_support_ex+0x2c/0x90 [amdgpu]
[ 40.963906] ? srso_alias_return_thunk+0x5/0x7f
[ 40.963909] ? dml2_core_calcs_mode_support_ex+0x2c/0x90 [amdgpu]
[ 40.964078] core_dcn4_mode_support+0x72/0xbf0 [amdgpu]
[ 40.964247] dml2_top_optimization_perform_optimization_phase+0x1d3/0x2a0 [amdgpu]
[ 40.964420] dml2_build_mode_programming+0x23d/0x750 [amdgpu]
[ 40.964587] dml21_validate+0x274/0x770 [amdgpu]
[ 40.964761] ? srso_alias_return_thunk+0x5/0x7f
[ 40.964763] ? resource_append_dpp_pipes_for_plane_composition+0x27c/0x3b0 [amdgpu]
[ 40.964942] dml2_validate+0x504/0x750 [amdgpu]
[ 40.965117] ? dml21_copy+0x95/0xb0 [amdgpu]
[ 40.965291] ? srso_alias_return_thunk+0x5/0x7f
[ 40.965295] dcn401_validate_bandwidth+0x4e/0x70 [amdgpu]
[ 40.965491] update_planes_and_stream_state+0x38d/0x5c0 [amdgpu]
[ 40.965672] update_planes_and_stream_v3+0x52/0x1e0 [amdgpu]
[ 40.965845] ? srso_alias_return_thunk+0x5/0x7f
[ 40.965849] dc_update_planes_and_stream+0x71/0xb0 [amdgpu]
Fix this by adding a guard for checking cursor width before triggering
the size calculation.
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-08
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: loongson3: Use raw_smp_processor_id() in do_service_request()
Use raw_smp_processor_id() instead of plain smp_processor_id() in
do_service_request(), otherwise we may get some errors with the driver
enabled:
BUG: using smp_processor_id() in preemptible [00000000] code: (udev-worker)/208
caller is loongson3_cpufreq_probe+0x5c/0x250 [loongson3_cpufreq]
CVSS Score
5.5
EPSS Score
0.002
Published
2024-11-08