| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers()
Previously fsg_num_buffers_validate() was removed as it was not
necessary due to Kconfig setting the limits for n from 2 to 256 with
default as 2. However, setting the page content in such a way that
kstrtou8() reflects n value as either 0 or 1 bypasses these
restrictions leading to a null pointer dereference if n is 0. Fix
this by adding a check for n < 2 and returning -EINVAL if n is
either 0 or 1 consistent with Kconfig logic. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_midi: initialize work in f_midi_alloc()
f_midi_alloc initializes free_ref to 1 and it can only be incremented
when a sound card is registered via f_midi_register_card().
f_midi_register_card() is only called in f_midi_bind() which actually
performs INIT_WORK. If f_midi_bind() is never run, work is not
initialized and the if condition in f_midi_free becomes true,
this results in a warning later in __flush_work as work->func = 0.
Fix this by moving INIT_WORK from f_midi_bind() to f_midi_alloc(). |
| In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: fix NULL pointer dereference in gadget_dev_ioctl()
gadget_dev_ioctl() reads dev->gadget before acquiring dev->lock, but
dev->state is checked after acquiring the lock. Therefore a concurrent
bind can change the device state between these operations, which can
leave ioctl with a stale NULL gadget pointer and causing a NULL pointer
dereference at gadget->ops->ioctl.
Read dev->gadget while holding dev->lock so that the gadget pointer
and device state are sampled consistently. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: fix null pointer dereference in usb_put_function_instance()
usb_put_function_instance() attempts to dereference fd inside fi struct
to get mod in uvc_alloc_inst() error path. However, fd is not allocated
until later in try_get_usb_function_instance() after allocating fi in
uvc_alloc_inst() and thus guranteed to be null in error path. Fix this
by adding a null check for fi->fd that returns if fd is null. |
| In the Linux kernel, the following vulnerability has been resolved:
xhci: fix lost bounce buffers on TDs spanning several ring segments
When a TD reaches a link TRB with data that is not aligned to the
endpoint's wMaxPacketSize, xhci_align_td() stages the unalignable tail
through the bounce buffer of the ring segment holding that link TRB.
xhci_unmap_td_bounce_buffer() later unmaps it and, for IN transfers,
copies the data back into the URB's buffer.
The enqueue path records the segment that was bounced in td->bounce_seg,
under the assumption that a TD never spans more than two ring segments.
That assumption does not hold: a TD large enough to span three or more
segments crosses several link TRBs and can be bounced at each of them.
Only the last one survives in td->bounce_seg, so every earlier bounce
buffer is neither copied back nor DMA unmapped.
The URB still completes with actual_length equal to the requested length
and no error, so the transfer looks successful while a wMaxPacketSize
sized hole in the destination buffer silently keeps its previous
contents. It also leaks a DMA mapping per dropped bounce.
Any sufficiently large and fragmented bulk transfer can hit this. It was
found with a USB mass storage device behind xHCI backing a dm-verity
target with 512 byte hash blocks, where the stale data is detected rather
than silently consumed. The device enumerates as SuperSpeed, so
wMaxPacketSize is 1024, while dm-bufio issues one 512 byte bio per hash
block. verity_prefetch_io() makes the block layer merge hundreds of them
into a single request of up to 512 scatterlist entries of 512 bytes each.
At 256 TRBs per ring segment such a TD spans three segments, and every
segment boundary falls on an odd multiple of 512, i.e. unaligned to
wMaxPacketSize. dm-bufio then caches a hash block holding stale data and
dm-verity declares the metadata block corrupted:
device-mapper: verity: 8:2: metadata block 10850 is corrupted
A reproducer running this under qemu is available at
https://github.com/baloo/xhci-verity
The bounce state (bounce_buf, bounce_dma, bounce_len, bounce_offs)
already lives on the ring segment, so there is nothing extra to track.
Keep recording the last bounced segment in td->bounce_seg and, on
completion, walk the segments from td->start_seg up to it, unmapping
every segment that still has a pending bounce.
Stopping at td->bounce_seg rather than td->end_seg matters: a bounce
implies the TD continues past that segment's link TRB, so bounce_seg is
always strictly before end_seg, and a later TD may already have started
in end_seg and been bounced there. Walking that far would copy a foreign
bounce buffer into this URB and unmap it twice. It also keeps the walk
correct if a TD ever wraps the whole ring so that end_seg == start_seg.
[mn: Add ring->num_segs check to prevent unlikely infinite for loop.] |
| In the Linux kernel, the following vulnerability has been resolved:
samples/damon/mtier: handle damon_stop() failure
damon_sample_mtier_stop() assumes its damon_stop() call will always
successfully stops the two DAMON contexts. Hence it deallocates the two
DAMON contexts after the damon_stop() call. However, if a given context
is already stopped, damon_stop() fails and returns an error while letting
the DAMON contexts that have not yet stopped keep running. This kind of
unexpected early DAMON context stops could happen due to memory allocation
failures in kdamond_fn(). Because damon_sample_mtier_stop() just
deallocates all DAMON contexts with damon_target and damon_region objects
that are linked to the contexts, the execution of the unstopped DAMON
context (kdamond) ends up using the memory that freed (use-after-free).
Fix the issue by separating the damon_stop() to be invoked per context.
Note that DAMON_SYSFS also allows multiple DAMON contexts execution. But,
it calls damon_stop() for each context one by one. Hence this issue is
only in mtier.
For the long term, it would be better to refactor damon_stop() to always
ensure stopping all contexts regardless of the failures in the middle.
Make this fix in the current way, though, to keep it simple and easy to
backport. I will do the refactoring later.
The issue was discovered [1] by Sashiko. |
| In the Linux kernel, the following vulnerability has been resolved:
samples/damon/wsse: handle damon_start() failure
Patch series "samples/damon: handle damon_{start,stop}() failures".
All DAMON sample modules are not correctly handling failures from
damon_start(). Among those, mtier also has an additional problem for
handling of damon_stop() failures. wsse and prcl also have a problem in
their damon_call() failure handling. As a result, memory leaks, next
DAMON operation disruptions, and use-after-free can happen. Fix those.
Note that only the damon_start() failure caused issues can reliably be
reproduced. Reproducing those issues require the admin permission,
though.
This patch (of 6):
damon_sample_wsse_start() callers assume it will clean up resources when
it fails. And the function does the cleanup for context buildup failures.
However, it is not doing the cleanup for damon_start() failure. As a
result, when damon_start() fails, it leaks the memory for DAMON context.
Free the context in case of the failure to fix the issues.
Note that the issue can reliably be reproduced because the module calls
damon_start() in the exclusive mode. For example,
$ sudo damo start
$ echo $$ | sudo tee /sys/module/damon_sample_wsse/parameters/target_pid
$ echo Y | sudo tee /sys/module/damon_sample_wsse/parameters/enabled
$ sudo cat /proc/allocinfo | grep damon_new_ctx
Because the first command is running another DAMON instance, the third
command fails the damon_start() call because the new DAMON instance cannot
exclusively run. And without this fix, by repeating the third and the
fourth commands above, we can show the memory consumption is only
increasing due to the leaks. It requires the sudo permission though.
The issue was discovered [1] by Sashiko. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/damon/core: handle region split failure in apply_min_nr_regions()
damon_apply_min_nr_regions() repeatedly split each region until its size
becomes small enough to meet the user-defined low limit of the number of
regions. The loop assumes the split operation (damon_split_region_at())
will always succeed and create the new region. But the operation could
silently fail for memory allocation failures, for example.
If such failure happens and the region was the last region, the linked
list-based next region fetching returns invalid pointer. As a result,
invalid memory dereference and corruption could happen. Even if the
corner case is handled, it imposes stress to the allocator by trying split
regions for other targets. Fix the issue by breaking all the loops for
any region split failure.
This means there could be a min_nr_regions violation. It will only rarely
happen since the allocation is arguably too small to fail. Even if it
happens, it is only temporal. damon_apply_min_nr_regions() will be called
again after the aggregation interval.
The user impact of the issue should be minor, since the allocation is
arguably too small to fail. But, it could still theoretically happen, and
the consequence is very bad.
This issue was discovered [1] by Sashiko. |
| In the Linux kernel, the following vulnerability has been resolved:
dma-buf: dma-heap: don't publish fd before copy_to_user() succeeds
DMA_HEAP_IOCTL_ALLOC allocates a dma-buf and installs an fd into the
caller's fd table via dma_buf_fd() -> fd_install() before
dma_heap_ioctl() copies the result back to userspace. If the trailing
copy_to_user() fails, userspace never learns the fd number, but the
fd (and the underlying dma-buf reference) are already visible to
other threads in the same process and are leaked for the lifetime of
the process.
The obvious "close it on the failure path" fix is unsafe: once
fd_install() has run, another thread can already dup() the fd, send
it via SCM_RIGHTS, or close() it and let its number be reused, so a
subsequent close_fd() from the ioctl path can operate on an unrelated
file. This was pointed out by Christian König on v1 [1].
Restructure the allocation path so that fd_install() is the last,
unfailable step of a successful ioctl:
1. heap->ops->allocate() creates the dma_buf.
2. get_unused_fd_flags() reserves an fd number in the caller's
fd table without publishing it, so
no other thread can observe it.
3. copy_to_user() delivers the fd number to userspace;
on failure the fd is returned with
put_unused_fd() and the dma_buf
reference is dropped with
dma_buf_put(), leaving no user-
visible state behind.
4. dma_buf_fd_install() publishes the fd and emits the
trace_dma_buf_fd tracepoint -- from
here on the ioctl cannot fail.
A new dma_buf_fd_install() helper is introduced in dma-buf.c to wrap
fd_install() together with the DMA_BUF_TRACE() call, preserving the
export tracing that dma_buf_fd() provides. dma_heap_ioctl_allocate()
is refactored to return the struct dma_buf * directly (returning
ERR_PTR on failure) so the caller holds the dmabuf reference across
steps 3 and 4.
The failure at step 3 is easily reachable from userspace: pass a
struct dma_heap_allocation_data that lives in a page whose protection
is flipped to PROT_READ between copy_from_user() and copy_to_user()
(e.g. via mprotect()). Before this change each such ioctl leaks one
dmabuf fd; after it, the fd table is unchanged on failure and only
/dev/dma_heap/<name> remains open.
No UAPI or heap-driver interface change.
[1] https://lore.kernel.org/dri-devel/175e98de-f414-47d7-81c1-c0fe0a8f7f62@amd.com/ |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: dw-edma: Initialize IRQ data before requesting IRQs
dw_edma_irq_request() passes struct dw_edma_irq to request_irq() before
dw_edma_channel_setup() fills the back pointer. A shared interrupt can
therefore enter the handler with dw_irq->dw still NULL, leading to a
NULL pointer dereference.
Set the back pointer before installing each handler. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix infinite loop in pcpu_freelist push with one possible CPU
__pcpu_freelist_push() can loop forever when only one CPU is possible
and an NMI re-enters pcpu_freelist_push() while the interrupted context
holds that CPU's freelist lock.
After the current-CPU fast path fails, the fallback loop walks
cpu_possible_mask while skipping the current CPU. With CONFIG_SMP=n, or
when an SMP kernel is limited to one possible CPU with nr_cpus=1 or
possible_cpus=1, there are no other possible CPUs to examine. The loop
therefore makes no lock acquisition attempt and can never make progress.
The following stack was observed on a UP system:
NMI context:
pcpu_freelist_push
free_htab_elem
htab_map_delete_elem
[perf-event BPF program]
__perf_event_overflow
perf_event_nmi_handler
exc_nmi
Interrupted context:
__pcpu_freelist_push
pcpu_freelist_push
free_htab_elem
htab_map_delete_elem
[raw_tp/sys_enter BPF program]
__bpf_trace_sys_enter
do_syscall_64
raw_res_spin_lock() detects the same-CPU recursive acquisition and
returns -EDEADLK, but the subsequent fallback loop has no candidate head
on a system with one possible CPU.
Restore the extra fallback head that existed before the rqspinlock
conversion. Keep the current-CPU fast path, then try the other possible
CPUs and finally the extra head. The additional head lets a push, which
cannot fail without losing a preallocated element, make progress when the
only per-CPU head is held by the interrupted context.
Also check the extra head from the pop path so that nodes placed there
can be reused. |
| In the Linux kernel, the following vulnerability has been resolved:
ima: Check for ERR_PTR from dentry_path() in validate_hash_algo()
dentry_path() returns ERR_PTR(-ENAMETOOLONG) when the path exceeds the
buffer. validate_hash_algo() passes the result straight to
integrity_audit_msg() without checking. ERR_PTR is not NULL, so
integrity_audit_message() sees a valid pointer and calls strlen() on
it, which faults:
BUG: unable to handle page fault for address: ffffffffffffffdc
RIP: 0010:strlen+0x30/0xa0
Call Trace:
audit_log_untrustedstring+0x19/0x30
integrity_audit_message+0x366/0x4f0
ima_inode_setxattr+0x512/0x5f0
Check for IS_ERR() and use NULL instead, which makes the audit message
skip the name= field instead of crashing. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: transfer the pmd dirty bit to the folio on zap
zap_huge_pmd_folio() propagates the pmd young bit to the folio for the
file case, but not the dirty bit. The pte path does propagate it, in
zap_present_folio_ptes() and so does the pmd split path, in
__split_huge_pmd_locked().
For most file mappings the omission is harmless, because writing to a
shared file mapping goes through page_mkwrite(), which dirties the folio.
tmpfs is different: it has no page_mkwrite(), and vma_wants_writenotify()
is false for it, so a *read* fault on a MAP_SHARED tmpfs mapping installs
a writable pmd via do_read_fault(). do_read_fault() does not call
fault_dirty_shared_page(), so subsequent stores through that mapping set
only the hardware dirty bit in the pmd and never call folio_mark_dirty().
A shmem folio allocated by a fault is marked uptodate but not dirty (see
the clear: block in shmem_get_folio_gfp()), so PG_dirty is never set at
all.
Unmapping such a folio - munmap(), or exit_mmap() when the process dies -
then loses the only record that it was written, because zap_huge_pmd()
drops the pmd without transferring the dirty bit. Reclaim afterwards sees
a clean shmem folio: the whole swap-out block in shrink_folio_list() is
inside "if (folio_test_dirty(folio))", so pageout() is skipped and the
folio falls into __remove_mapping(). There, folio_is_file_lru() is false
for a swapbacked folio, so no shadow entry is created and
__filemap_remove_folio(folio, NULL) simply empties the i_pages slot. The
data is freed without ever being written to swap, and the next fault on
that index returns a freshly zeroed folio.
This is silent data loss for any process that keeps state in a MAP_SHARED
tmpfs segment across an unmap - for example a cache handed from one
process generation to the next through /dev/shm. It requires the folio to
be PMD-mapped, so it only shows up once shmem THP is enabled (which is
what we did in Meta fleet and started noticing crashes); with THP off the
pte path transfers the dirty bit correctly. It also only becomes visible
when swap is enabled, because with no swap device shmem folios (which are
on the anon LRU) are not scanned by reclaim at all, so the clean folio is
never dropped.
Reproduced on x86_64 with a tmpfs mounted huge=within_size: read-fault a
2MB-backed region, write a known pattern through the resulting mapping,
munmap, force reclaim of the cgroup, then re-map and read back. Without
this patch the region reads back as zeros and vmstat shows zswpout 0 - the
data was discarded rather than swapped. With this patch the region reads
back correctly and the pages are swapped out as expected. With
huge=never, or when the first touch is a write, the test passes either
way. |
| In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix kernel address leakages in LBR stack
Before Arch LBR gained CPL filtering support, a user-only branch stack
could still contain kernel addresses. As a result, kernel branch records
may be exposed to user space even when PERF_SAMPLE_BRANCH_USER is
requested.
For example, on Intel Tiger Lake, the following command can still report
SYSRET/ERET entries with kernel-space from addresses:
$ ./perf record -e cycles:p -o - --branch-filter any,save_type,u -- \
./perf bench syscall basic --loop 1000 | \
./perf script -i - --fields brstack|tr ' ' '\n'| \
grep -E '0x[89a-f][0-9a-f]{15}'
Total time: 0.000 [sec]
0.219000 usecs/op
4,566,210 ops/sec
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.551 MB - ]
0xffffffff93c001c8/0x7f12a2b1d647/P/-/-/16959/SYSRET/-
0xffffffff93c001c8/0x7f12a2b1d5c2/P/-/-/17535/SYSRET/-
0xffffffff93c01928/0x7f12a2861000/P/-/-/6719/ERET/-
0xffffffff93c01928/0x7f12a297a000/P/-/-/8575/ERET/-
The problem is that intel_pmu_lbr_filter() does not fully validate the
privilege level of sampled entries. It filters some mismatches based on
the branch type and the to address, but it does not reject entries whose
from address violates the requested branch privilege filter.
Fix this by extending software filtering to validate both from and to
addresses against br_sel. Any LBR entry contains kernel address does not
match the requested user filter is dropped. This prevents kernel
addresses from appearing in user-only branch stacks. |
| In the Linux kernel, the following vulnerability has been resolved:
i2c: core: fix debugfs UAF on adapter removal
i2c_del_adapter() frees the adapter's debugfs directory before it
unregisters the adapter device, but the new_device sysfs attribute
stays writable until device_del(). A write racing with removal still
reaches i2c_device_probe(), which passes the freed adap->debugfs to
debugfs_create_dir() as the new client's parent:
BUG: KASAN: slab-use-after-free in lookup_noperm_common+0x407/0x430
Read of size 4 at addr ffff88803ef87810 by task syz.0.61/6090
lookup_noperm_common+0x407/0x430
simple_start_creating+0x9c/0x110
debugfs_start_creating+0xdb/0x1a0
debugfs_create_dir+0x24/0x350
i2c_device_probe+0x814/0xbf0
It's technically possible to create a client after i2c_deregister_clients
has run. That client will never be unregistered and make
wait_for_completion hang.
Close the window by removing the new_device attribute at the start of
i2c_del_adapter(). device_remove_file() will drain any clients left. |
| In the Linux kernel, the following vulnerability has been resolved:
i2c: mux: Fix channel node leak on adapter add failure
i2c_mux_add_adapter() takes a reference to the Device Tree channel node
before registering the new adapter. If adapter registration fails, the
error path frees the private data without dropping that reference.
Release the channel node before freeing the private data. |
| In the Linux kernel, the following vulnerability has been resolved:
arm64: Don't read GMID_EL1 when MTE is disabled
__cpuinfo_store_cpu() gates the GMID_EL1 read on the raw
ID_AA64PFR1_EL1, so it reads the register even when the kernel has
disabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5
in that case, and pKVM injects an UNDEF the host cannot handle:
Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP
pc : __cpuinfo_store_cpu+0xf4/0x264
Kernel panic - not syncing: Attempted to kill the idle task!
Only pKVM reaches it, and only after a CPU is offlined and brought back
online: its CPU_ON relay sets the host HCR before the CPU enters EL1,
while plain nVHE sets it at CPUHP_AP_KVM_ONLINE.
Gate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line
override applied, and on CONFIG_ARM64_MTE, which no register reflects.
The boot CPU stores its registers before init_cpu_features() strips an
unsafe override, so clamp against the hardware value here too. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: return early from a zero-length flush
SYNC_BO does not constrain its size, so a request for zero bytes reaches
drm_clflush_virt_range(), which ends with an unconditional
clflushopt(end - 1). For an empty range that is the byte before the
mapping, and abo->mem.kva comes from vmap(), so the access lands in the
guard page below the vmalloc area and faults:
BUG: unable to handle page fault for address: ffffd16fbbc70fff
#PF: supervisor read access in kernel mode
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 7 UID: 1000 Comm: sync_bo_probe
RIP: 0010:drm_clflush_virt_range+0x3c/0x70
Call Trace:
amdxdna_drm_sync_bo_ioctl+0x124/0x430 [amdxdna]
drm_ioctl+0x301/0x4c0
__x64_sys_ioctl+0x115/0x2f0
do_syscall_64+0xa6/0x3d0
Any process that can open the render node can do this. Reproduced 3 of 3
times on a Strix Point NPU (1022:17f0), by calling SYNC_BO with size 0 on
an AMDXDNA_BO_SHARE object. The import arm takes the same request but
flushes the whole scatterlist, so it survives it.
Nothing needs flushing for an empty range, so answer before choosing a
path. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/ethosu: check MMIO mapping errors in probe
devm_platform_ioremap_resource() returns an error pointer when the register
resource cannot be mapped. ethosu_probe() stores it and continues until
initialization dereferences it through MMIO accessors.
Return the mapping error before initializing the device. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/ethosu: fix job completion fence cleanup
ethosu_ioctl_submit_job() allocates done_fence before validating buffer
handles. Errors after allocation call ethosu_job_err_cleanup(), which frees
the job but leaks the uninitialized fence.
A scheduler dependency error also lets ethosu_job_run() return before
dma_fence_init(). Normal cleanup then passes a zeroed refcount to
dma_fence_put().
Release done_fence in the common cleanup path and use
dma_fence_was_initialized() to distinguish initialized fences from raw
allocations.
[robh: also fix goto] |
