In the Linux kernel, the following vulnerability has been resolved:
regulator: core: fix NULL dereference on unbind due to stale coupling data
Failing to reset coupling_desc.n_coupled after freeing coupled_rdevs can
lead to NULL pointer dereference when regulators are accessed post-unbind.
This can happen during runtime PM or other regulator operations that rely
on coupling metadata.
For example, on ridesx4, unbinding the 'reg-dummy' platform device triggers
a panic in regulator_lock_recursive() due to stale coupling state.
Ensure n_coupled is set to 0 to prevent access to invalid pointers.
In the Linux kernel, the following vulnerability has been resolved:
arm64/entry: Mask DAIF in cpu_switch_to(), call_on_irq_stack()
`cpu_switch_to()` and `call_on_irq_stack()` manipulate SP to change
to different stacks along with the Shadow Call Stack if it is enabled.
Those two stack changes cannot be done atomically and both functions
can be interrupted by SErrors or Debug Exceptions which, though unlikely,
is very much broken : if interrupted, we can end up with mismatched stacks
and Shadow Call Stack leading to clobbered stacks.
In `cpu_switch_to()`, it can happen when SP_EL0 points to the new task,
but x18 stills points to the old task's SCS. When the interrupt handler
tries to save the task's SCS pointer, it will save the old task
SCS pointer (x18) into the new task struct (pointed to by SP_EL0),
clobbering it.
In `call_on_irq_stack()`, it can happen when switching from the task stack
to the IRQ stack and when switching back. In both cases, we can be
interrupted when the SCS pointer points to the IRQ SCS, but SP points to
the task stack. The nested interrupt handler pushes its return addresses
on the IRQ SCS. It then detects that SP points to the task stack,
calls `call_on_irq_stack()` and clobbers the task SCS pointer with
the IRQ SCS pointer, which it will also use !
This leads to tasks returning to addresses on the wrong SCS,
or even on the IRQ SCS, triggering kernel panics via CONFIG_VMAP_STACK
or FPAC if enabled.
This is possible on a default config, but unlikely.
However, when enabling CONFIG_ARM64_PSEUDO_NMI, DAIF is unmasked and
instead the GIC is responsible for filtering what interrupts the CPU
should receive based on priority.
Given the goal of emulating NMIs, pseudo-NMIs can be received by the CPU
even in `cpu_switch_to()` and `call_on_irq_stack()`, possibly *very*
frequently depending on the system configuration and workload, leading
to unpredictable kernel panics.
Completely mask DAIF in `cpu_switch_to()` and restore it when returning.
Do the same in `call_on_irq_stack()`, but restore and mask around
the branch.
Mask DAIF even if CONFIG_SHADOW_CALL_STACK is not enabled for consistency
of behaviour between all configurations.
Introduce and use an assembly macro for saving and masking DAIF,
as the existing one saves but only masks IF.
In the Linux kernel, the following vulnerability has been resolved:
i2c: qup: jump out of the loop in case of timeout
Original logic only sets the return value but doesn't jump out of the
loop if the bus is kept active by a client. This is not expected. A
malicious or buggy i2c client can hang the kernel in this case and
should be avoided. This is observed during a long time test with a
PCA953x GPIO extender.
Fix it by changing the logic to not only sets the return value, but also
jumps out of the loop and return to the caller with -ETIMEDOUT.
In the Linux kernel, the following vulnerability has been resolved:
gfs2: No more self recovery
When a node withdraws and it turns out that it is the only node that has
the filesystem mounted, gfs2 currently tries to replay the local journal
to bring the filesystem back into a consistent state. Not only is that
a very bad idea, it has also never worked because gfs2_recover_func()
will refuse to do anything during a withdraw.
However, before even getting to this point, gfs2_recover_func()
dereferences sdp->sd_jdesc->jd_inode. This was a use-after-free before
commit 04133b607a78 ("gfs2: Prevent double iput for journal on error")
and is a NULL pointer dereference since then.
Simply get rid of self recovery to fix that.
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: reject invalid file types when reading inodes
To prevent inodes with invalid file types from tripping through the vfs
and causing malfunctions or assertion failures, add a missing sanity check
when reading an inode from a block device. If the file type is not valid,
treat it as a filesystem error.
In the Linux kernel, the following vulnerability has been resolved:
ice: Fix a null pointer dereference in ice_copy_and_init_pkg()
Add check for the return value of devm_kmemdup()
to prevent potential null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode
Andrei Lalaev reported a NULL pointer deref when a CAN device is
restarted from Bus Off and the driver does not implement the struct
can_priv::do_set_mode callback.
There are 2 code path that call struct can_priv::do_set_mode:
- directly by a manual restart from the user space, via
can_changelink()
- delayed automatic restart after bus off (deactivated by default)
To prevent the NULL pointer deference, refuse a manual restart or
configure the automatic restart delay in can_changelink() and report
the error via extack to user space.
As an additional safety measure let can_restart() return an error if
can_priv::do_set_mode is not set instead of dereferencing it
unchecked.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid out-of-boundary access in devs.path
- touch /mnt/f2fs/012345678901234567890123456789012345678901234567890123
- truncate -s $((1024*1024*1024)) \
/mnt/f2fs/012345678901234567890123456789012345678901234567890123
- touch /mnt/f2fs/file
- truncate -s $((1024*1024*1024)) /mnt/f2fs/file
- mkfs.f2fs /mnt/f2fs/012345678901234567890123456789012345678901234567890123 \
-c /mnt/f2fs/file
- mount /mnt/f2fs/012345678901234567890123456789012345678901234567890123 \
/mnt/f2fs/loop
[16937.192225] F2FS-fs (loop0): Mount Device [ 0]: /mnt/f2fs/012345678901234567890123456789012345678901234567890123\xff\x01, 511, 0 - 3ffff
[16937.192268] F2FS-fs (loop0): Failed to find devices
If device path length equals to MAX_PATH_LEN, sbi->devs.path[] may
not end up w/ null character due to path array is fully filled, So
accidently, fields locate after path[] may be treated as part of
device path, result in parsing wrong device path.
struct f2fs_dev_info {
...
char path[MAX_PATH_LEN];
...
};
Let's add one byte space for sbi->devs.path[] to store null
character of device path string.
In the Linux kernel, the following vulnerability has been resolved:
hfsplus: remove mutex_lock check in hfsplus_free_extents
Syzbot reported an issue in hfsplus filesystem:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4400 at fs/hfsplus/extents.c:346
hfsplus_free_extents+0x700/0xad0
Call Trace:
<TASK>
hfsplus_file_truncate+0x768/0xbb0 fs/hfsplus/extents.c:606
hfsplus_write_begin+0xc2/0xd0 fs/hfsplus/inode.c:56
cont_expand_zero fs/buffer.c:2383 [inline]
cont_write_begin+0x2cf/0x860 fs/buffer.c:2446
hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
generic_cont_expand_simple+0x151/0x250 fs/buffer.c:2347
hfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263
notify_change+0xe38/0x10f0 fs/attr.c:420
do_truncate+0x1fb/0x2e0 fs/open.c:65
do_sys_ftruncate+0x2eb/0x380 fs/open.c:193
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
To avoid deadlock, Commit 31651c607151 ("hfsplus: avoid deadlock
on file truncation") unlock extree before hfsplus_free_extents(),
and add check wheather extree is locked in hfsplus_free_extents().
However, when operations such as hfsplus_file_release,
hfsplus_setattr, hfsplus_unlink, and hfsplus_get_block are executed
concurrently in different files, it is very likely to trigger the
WARN_ON, which will lead syzbot and xfstest to consider it as an
abnormality.
The comment above this warning also describes one of the easy
triggering situations, which can easily trigger and cause
xfstest&syzbot to report errors.
[task A] [task B]
->hfsplus_file_release
->hfsplus_file_truncate
->hfs_find_init
->mutex_lock
->mutex_unlock
->hfsplus_write_begin
->hfsplus_get_block
->hfsplus_file_extend
->hfsplus_ext_read_extent
->hfs_find_init
->mutex_lock
->hfsplus_free_extents
WARN_ON(mutex_is_locked) !!!
Several threads could try to lock the shared extents tree.
And warning can be triggered in one thread when another thread
has locked the tree. This is the wrong behavior of the code and
we need to remove the warning.