Linux: >> Linux Kernel >> 3.1.1 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
dm mirror log: round up region bitmap size to BITS_PER_LONG
The code in dm-log rounds up bitset_size to 32 bits. It then uses
find_next_zero_bit_le on the allocated region. find_next_zero_bit_le
accesses the bitmap using unsigned long pointers. So, on 64-bit
architectures, it may access 4 bytes beyond the allocated size.
Fix this bug by rounding up bitset_size to BITS_PER_LONG.
This bug was found by running the lvm2 testsuite with kasan.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
mm/slub: add missing TID updates on slab deactivation
The fastpath in slab_alloc_node() assumes that c->slab is stable as long as
the TID stays the same. However, two places in __slab_alloc() currently
don't update the TID when deactivating the CPU slab.
If multiple operations race the right way, this could lead to an object
getting lost; or, in an even more unlikely situation, it could even lead to
an object being freed onto the wrong slab's freelist, messing up the
`inuse` counter and eventually causing a page to be freed to the page
allocator while it still contains slab objects.
(I haven't actually tested these cases though, this is just based on
looking at the code. Writing testcases for this stuff seems like it'd be
a pain...)
The race leading to state inconsistency is (all operations on the same CPU
and kmem_cache):
- task A: begin do_slab_free():
- read TID
- read pcpu freelist (==NULL)
- check `slab == c->slab` (true)
- [PREEMPT A->B]
- task B: begin slab_alloc_node():
- fastpath fails (`c->freelist` is NULL)
- enter __slab_alloc()
- slub_get_cpu_ptr() (disables preemption)
- enter ___slab_alloc()
- take local_lock_irqsave()
- read c->freelist as NULL
- get_freelist() returns NULL
- write `c->slab = NULL`
- drop local_unlock_irqrestore()
- goto new_slab
- slub_percpu_partial() is NULL
- get_partial() returns NULL
- slub_put_cpu_ptr() (enables preemption)
- [PREEMPT B->A]
- task A: finish do_slab_free():
- this_cpu_cmpxchg_double() succeeds()
- [CORRUPT STATE: c->slab==NULL, c->freelist!=NULL]
From there, the object on c->freelist will get lost if task B is allowed to
continue from here: It will proceed to the retry_load_slab label,
set c->slab, then jump to load_freelist, which clobbers c->freelist.
But if we instead continue as follows, we get worse corruption:
- task A: run __slab_free() on object from other struct slab:
- CPU_PARTIAL_FREE case (slab was on no list, is now on pcpu partial)
- task A: run slab_alloc_node() with NUMA node constraint:
- fastpath fails (c->slab is NULL)
- call __slab_alloc()
- slub_get_cpu_ptr() (disables preemption)
- enter ___slab_alloc()
- c->slab is NULL: goto new_slab
- slub_percpu_partial() is non-NULL
- set c->slab to slub_percpu_partial(c)
- [CORRUPT STATE: c->slab points to slab-1, c->freelist has objects
from slab-2]
- goto redo
- node_match() fails
- goto deactivate_slab
- existing c->freelist is passed into deactivate_slab()
- inuse count of slab-1 is decremented to account for object from
slab-2
At this point, the inuse count of slab-1 is 1 lower than it should be.
This means that if we free all allocated objects in slab-1 except for one,
SLUB will think that slab-1 is completely unused, and may free its page,
leading to use-after-free.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
xtensa: Fix refcount leak bug in time.c
In calibrate_ccount(), of_find_compatible_node() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
dm raid: fix KASAN warning in raid5_add_disks
There's a KASAN warning in raid5_add_disk when running the LVM testsuite.
The warning happens in the test
lvconvert-raid-reshape-linear_to_raid6-single-type.sh. We fix the warning
by verifying that rdev->saved_raid_disk is within limits.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
dm raid: fix accesses beyond end of raid member array
On dm-raid table load (using raid_ctr), dm-raid allocates an array
rs->devs[rs->raid_disks] for the raid device members. rs->raid_disks
is defined by the number of raid metadata and image tupples passed
into the target's constructor.
In the case of RAID layout changes being requested, that number can be
different from the current number of members for existing raid sets as
defined in their superblocks. Example RAID layout changes include:
- raid1 legs being added/removed
- raid4/5/6/10 number of stripes changed (stripe reshaping)
- takeover to higher raid level (e.g. raid5 -> raid6)
When accessing array members, rs->raid_disks must be used in control
loops instead of the potentially larger value in rs->md.raid_disks.
Otherwise it will cause memory access beyond the end of the rs->devs
array.
Fix this by changing code that is prone to out-of-bounds access.
Also fix validate_raid_redundancy() to validate all devices that are
added. Also, use braces to help clean up raid_iterate_devices().
The out-of-bounds memory accesses was discovered using KASAN.
This commit was verified to pass all LVM2 RAID tests (with KASAN
enabled).
CVSS Score
7.1
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
xtensa: xtfpga: Fix refcount leak bug in setup
In machine_setup(), of_find_compatible_node() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
srcu: Tighten cleanup_srcu_struct() GP checks
Currently, cleanup_srcu_struct() checks for a grace period in progress,
but it does not check for a grace period that has not yet started but
which might start at any time. Such a situation could result in a
use-after-free bug, so this commit adds a check for a grace period that
is needed but not yet started to cleanup_srcu_struct().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
cipso: Fix data-races around sysctl.
While reading cipso sysctl variables, they can be changed concurrently.
So, we need to add READ_ONCE() to avoid data-races.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
icmp: Fix a data-race around sysctl_icmp_errors_use_inbound_ifaddr.
While reading sysctl_icmp_errors_use_inbound_ifaddr, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
CVSS Score
4.7
EPSS Score
0.0
Published
2025-02-26
In the Linux kernel, the following vulnerability has been resolved:
pinctrl: aspeed: Fix potential NULL dereference in aspeed_pinmux_set_mux()
pdesc could be null but still dereference pdesc->name and it will lead to
a null pointer access. So we move a null check before dereference.
CVSS Score
5.5
EPSS Score
0.001
Published
2025-02-26