Linux: >> Linux Kernel >> 4.14.20 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
VMCI: check context->notify_page after call to get_user_pages_fast() to avoid GPF
The call to get_user_pages_fast() in vmci_host_setup_notify() can return
NULL context->notify_page causing a GPF. To avoid GPF check if
context->notify_page == NULL and return error if so.
general protection fault, probably for non-canonical address
0xe0009d1000000060: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x0005088000000300-
0x0005088000000307]
CPU: 2 PID: 26180 Comm: repro_34802241 Not tainted 6.1.0-rc4 #1
Hardware name: Red Hat KVM, BIOS 1.15.0-2.module+el8.6.0 04/01/2014
RIP: 0010:vmci_ctx_check_signal_notify+0x91/0xe0
Call Trace:
<TASK>
vmci_host_unlocked_ioctl+0x362/0x1f40
__x64_sys_ioctl+0x1a1/0x230
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
CVSS Score
7.1
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: install stub fence into potential unused fence pointers
When using cpu to update page tables, vm update fences are unused.
Install stub fence into these fence pointers instead of NULL
to avoid NULL dereference when calling dma_fence_wait() on them.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
cacheinfo: Fix shared_cpu_map to handle shared caches at different levels
The cacheinfo sets up the shared_cpu_map by checking whether the caches
with the same index are shared between CPUs. However, this will trigger
slab-out-of-bounds access if the CPUs do not have the same cache hierarchy.
Another problem is the mismatched shared_cpu_map when the shared cache does
not have the same index between CPUs.
CPU0 I D L3
index 0 1 2 x
^ ^ ^ ^
index 0 1 2 3
CPU1 I D L2 L3
This patch checks each cache is shared with all caches on other CPUs.
CVSS Score
7.1
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
nfsd: call op_release, even when op_func returns an error
For ops with "trivial" replies, nfsd4_encode_operation will shortcut
most of the encoding work and skip to just marshalling up the status.
One of the things it skips is calling op_release. This could cause a
memory leak in the layoutget codepath if there is an error at an
inopportune time.
Have the compound processing engine always call op_release, even when
op_func sets an error in op->status. With this change, we also need
nfsd4_block_get_device_info_scsi to set the gd_device pointer to NULL
on error to avoid a double free.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
media: pci: tw68: Fix null-ptr-deref bug in buf prepare and finish
When the driver calls tw68_risc_buffer() to prepare the buffer, the
function call dma_alloc_coherent may fail, resulting in a empty buffer
buf->cpu. Later when we free the buffer or access the buffer, null ptr
deref is triggered.
This bug is similar to the following one:
https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.
We believe the bug can be also dynamically triggered from user side.
Similarly, we fix this by checking the return value of tw68_risc_buffer()
and the value of buf->cpu before buffer free.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
scsi: storvsc: Fix handling of virtual Fibre Channel timeouts
Hyper-V provides the ability to connect Fibre Channel LUNs to the host
system and present them in a guest VM as a SCSI device. I/O to the vFC
device is handled by the storvsc driver. The storvsc driver includes a
partial integration with the FC transport implemented in the generic
portion of the Linux SCSI subsystem so that FC attributes can be displayed
in /sys. However, the partial integration means that some aspects of vFC
don't work properly. Unfortunately, a full and correct integration isn't
practical because of limitations in what Hyper-V provides to the guest.
In particular, in the context of Hyper-V storvsc, the FC transport timeout
function fc_eh_timed_out() causes a kernel panic because it can't find the
rport and dereferences a NULL pointer. The original patch that added the
call from storvsc_eh_timed_out() to fc_eh_timed_out() is faulty in this
regard.
In many cases a timeout is due to a transient condition, so the situation
can be improved by just continuing to wait like with other I/O requests
issued by storvsc, and avoiding the guaranteed panic. For a permanent
failure, continuing to wait may result in a hung thread instead of a panic,
which again may be better.
So fix the panic by removing the storvsc call to fc_eh_timed_out(). This
allows storvsc to keep waiting for a response. The change has been tested
by users who experienced a panic in fc_eh_timed_out() due to transient
timeouts, and it solves their problem.
In the future we may want to deprecate the vFC functionality in storvsc
since it can't be fully fixed. But it has current users for whom it is
working well enough, so it should probably stay for a while longer.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix DFS traversal oops without CONFIG_CIFS_DFS_UPCALL
When compiled with CONFIG_CIFS_DFS_UPCALL disabled, cifs_dfs_d_automount
is NULL. cifs.ko logic for mapping CIFS_FATTR_DFS_REFERRAL attributes to
S_AUTOMOUNT and corresponding dentry flags is retained regardless of
CONFIG_CIFS_DFS_UPCALL, leading to a NULL pointer dereference in
VFS follow_automount() when traversing a DFS referral link:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
<TASK>
__traverse_mounts+0xb5/0x220
? cifs_revalidate_mapping+0x65/0xc0 [cifs]
step_into+0x195/0x610
? lookup_fast+0xe2/0xf0
path_lookupat+0x64/0x140
filename_lookup+0xc2/0x140
? __create_object+0x299/0x380
? kmem_cache_alloc+0x119/0x220
? user_path_at_empty+0x31/0x50
user_path_at_empty+0x31/0x50
__x64_sys_chdir+0x2a/0xd0
? exit_to_user_mode_prepare+0xca/0x100
do_syscall_64+0x42/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
This fix adds an inline cifs_dfs_d_automount() {return -EREMOTE} handler
when CONFIG_CIFS_DFS_UPCALL is disabled. An alternative would be to
avoid flagging S_AUTOMOUNT, etc. without CONFIG_CIFS_DFS_UPCALL. This
approach was chosen as it provides more control over the error path.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
btrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand
While trying to get the subpage blocksize tests running, I hit the
following panic on generic/476
assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229
kernel BUG at fs/btrfs/subpage.c:229!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 1 PID: 1453 Comm: fsstress Not tainted 6.4.0-rc7+ #12
Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230301gitf80f052277c8-26.fc38 03/01/2023
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : btrfs_subpage_assert+0xbc/0xf0
lr : btrfs_subpage_assert+0xbc/0xf0
Call trace:
btrfs_subpage_assert+0xbc/0xf0
btrfs_subpage_clear_checked+0x38/0xc0
btrfs_page_clear_checked+0x48/0x98
btrfs_truncate_block+0x5d0/0x6a8
btrfs_cont_expand+0x5c/0x528
btrfs_write_check.isra.0+0xf8/0x150
btrfs_buffered_write+0xb4/0x760
btrfs_do_write_iter+0x2f8/0x4b0
btrfs_file_write_iter+0x1c/0x30
do_iter_readv_writev+0xc8/0x158
do_iter_write+0x9c/0x210
vfs_iter_write+0x24/0x40
iter_file_splice_write+0x224/0x390
direct_splice_actor+0x38/0x68
splice_direct_to_actor+0x12c/0x260
do_splice_direct+0x90/0xe8
generic_copy_file_range+0x50/0x90
vfs_copy_file_range+0x29c/0x470
__arm64_sys_copy_file_range+0xcc/0x498
invoke_syscall.constprop.0+0x80/0xd8
do_el0_svc+0x6c/0x168
el0_svc+0x50/0x1b0
el0t_64_sync_handler+0x114/0x120
el0t_64_sync+0x194/0x198
This happens because during btrfs_cont_expand we'll get a page, set it
as mapped, and if it's not Uptodate we'll read it. However between the
read and re-locking the page we could have called release_folio() on the
page, but left the page in the file mapping. release_folio() can clear
the page private, and thus further down we blow up when we go to modify
the subpage bits.
Fix this by putting the set_page_extent_mapped() after the read. This
is safe because read_folio() will call set_page_extent_mapped() before
it does the read, and then if we clear page private but leave it on the
mapping we're completely safe re-setting set_page_extent_mapped(). With
this patch I can now run generic/476 without panicing.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dsi: Add missing check for alloc_ordered_workqueue
Add check for the return value of alloc_ordered_workqueue as it may return
NULL pointer and cause NULL pointer dereference.
Patchwork: https://patchwork.freedesktop.org/patch/517646/
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15
In the Linux kernel, the following vulnerability has been resolved:
spi: imx: Don't skip cleanup in remove's error path
Returning early in a platform driver's remove callback is wrong. In this
case the dma resources are not released in the error path. this is never
retried later and so this is a permanent leak. To fix this, only skip
hardware disabling if waking the device fails.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-15