Linux: >> Linux Kernel >> 6.1.0 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
comedi: Flush partial mappings in error case
If some remap_pfn_range() calls succeeded before one failed, we still have
buffer pages mapped into the userspace page tables when we drop the buffer
reference with comedi_buf_map_put(bm). The userspace mappings are only
cleaned up later in the mmap error path.
Fix it by explicitly flushing all mappings in our VMA on the error path.
See commit 79a61cc3fc04 ("mm: avoid leaving partial pfn mappings around in
error case").
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-24
In the Linux kernel, the following vulnerability has been resolved:
x86/xen: don't do PV iret hypercall through hypercall page
Instead of jumping to the Xen hypercall page for doing the iret
hypercall, directly code the required sequence in xen-asm.S.
This is done in preparation of no longer using hypercall page at all,
as it has shown to cause problems with speculation mitigations.
This is part of XSA-466 / CVE-2024-53241.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-24
In the Linux kernel, the following vulnerability has been resolved:
bpf: sync_linked_regs() must preserve subreg_def
Range propagation must not affect subreg_def marks, otherwise the
following example is rewritten by verifier incorrectly when
BPF_F_TEST_RND_HI32 flag is set:
0: call bpf_ktime_get_ns call bpf_ktime_get_ns
1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff
2: w1 = w0 rewrites w1 = w0
3: if w0 < 10 goto +0 --------------> r11 = 0x2f5674a6 (r)
4: r1 >>= 32 r11 <<= 32 (r)
5: r0 = r1 r1 |= r11 (r)
6: exit; if w0 < 0xa goto pc+0
r1 >>= 32
r0 = r1
exit
(or zero extension of w1 at (2) is missing for architectures that
require zero extension for upper register half).
The following happens w/o this patch:
- r0 is marked as not a subreg at (0);
- w1 is marked as subreg at (2);
- w1 subreg_def is overridden at (3) by copy_register_state();
- w1 is read at (5) but mark_insn_zext() does not mark (2)
for zero extension, because w1 subreg_def is not set;
- because of BPF_F_TEST_RND_HI32 flag verifier inserts random
value for hi32 bits of (2) (marked (r));
- this random value is read at (5).
CVSS Score
5.5
EPSS Score
0.0
Published
2024-12-04
In the Linux kernel, the following vulnerability has been resolved:
ima: fix buffer overrun in ima_eventdigest_init_common
Function ima_eventdigest_init() calls ima_eventdigest_init_common()
with HASH_ALGO__LAST which is then used to access the array
hash_digest_size[] leading to buffer overrun. Have a conditional
statement to handle this.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-12-02
In the Linux kernel, the following vulnerability has been resolved:
media: av7110: fix a spectre vulnerability
As warned by smatch:
drivers/staging/media/av7110/av7110_ca.c:270 dvb_ca_ioctl() warn: potential spectre issue 'av7110->ci_slot' [w] (local cap)
There is a spectre-related vulnerability at the code. Fix it.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-19
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
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Avoid overflow from uint32_t to uint8_t
[WHAT & HOW]
dmub_rb_cmd's ramping_boundary has size of uint8_t and it is assigned
0xFFFF. Fix it by changing it to uint8_t with value of 0xFF.
This fixes 2 INTEGER_OVERFLOW issues reported by Coverity.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Remove register from DCN35 DMCUB diagnostic collection
[Why]
These registers should not be read from driver and triggering the
security violation when DMCUB work times out and diagnostics are
collected blocks Z8 entry.
[How]
Remove the register read from DCN35.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Disable DMCUB timeout for DCN35
[Why]
DMCUB can intermittently take longer than expected to process commands.
Old ASIC policy was to continue while logging a diagnostic error - which
works fine for ASIC without IPS, but with IPS this could lead to a race
condition where we attempt to access DCN state while it's inaccessible,
leading to a system hang when the NIU port is not disabled or register
accesses that timeout and the display configuration in an undefined
state.
[How]
We need to investigate why these accesses take longer than expected, but
for now we should disable the timeout on DCN35 to avoid this race
condition. Since the waits happen only at lower interrupt levels the
risk of taking too long at higher IRQ and causing a system watchdog
timeout are minimal.
CVSS Score
4.7
EPSS Score
0.0
Published
2024-10-09
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Correct the defined value for AMDGPU_DMUB_NOTIFICATION_MAX
[Why & How]
It actually exposes '6' types in enum dmub_notification_type. Not 5. Using smaller
number to create array dmub_callback & dmub_thread_offload has potential to access
item out of array bound. Fix it.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-09