In the Linux kernel, the following vulnerability has been resolved:
virtio_console: eliminate anonymous module_init & module_exit
Eliminate anonymous module_init() and module_exit(), which can lead to
confusion or ambiguity when reading System.map, crashes/oops/bugs,
or an initcall_debug log.
Give each of these init and exit functions unique driver-specific
names to eliminate the anonymous names.
Example 1: (System.map)
ffffffff832fc78c t init
ffffffff832fc79e t init
ffffffff832fc8f8 t init
Example 2: (initcall_debug log)
calling init+0x0/0x12 @ 1
initcall init+0x0/0x12 returned 0 after 15 usecs
calling init+0x0/0x60 @ 1
initcall init+0x0/0x60 returned 0 after 2 usecs
calling init+0x0/0x9a @ 1
initcall init+0x0/0x9a returned 0 after 74 usecs
In the Linux kernel, the following vulnerability has been resolved:
habanalabs: fix possible memory leak in MMU DR fini
This patch fixes what seems to be copy paste error.
We will have a memory leak if the host-resident shadow is NULL (which
will likely happen as the DR and HR are not dependent).
In the Linux kernel, the following vulnerability has been resolved:
NFSv4.2: fix reference count leaks in _nfs42_proc_copy_notify()
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The reference counting issue happens in two error paths in the
function _nfs42_proc_copy_notify(). In both error paths, the function
simply returns the error code and forgets to balance the refcount of
object `ctx`, bumped by get_nfs_open_context() earlier, which may
cause refcount leaks.
Fix it by balancing refcount of the `ctx` object before the function
returns in both error paths.
In the Linux kernel, the following vulnerability has been resolved:
staging: vchiq_core: handle NULL result of find_service_by_handle
In case of an invalid handle the function find_servive_by_handle
returns NULL. So take care of this and avoid a NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
staging: wfx: fix an error handling in wfx_init_common()
One error handler of wfx_init_common() return without calling
ieee80211_free_hw(hw), which may result in memory leak. And I add
one err label to unify the error handler, which is useful for the
subsequent changes.
In the Linux kernel, the following vulnerability has been resolved:
mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0)
If an mremap() syscall with old_size=0 ends up in move_page_tables(), it
will call invalidate_range_start()/invalidate_range_end() unnecessarily,
i.e. with an empty range.
This causes a WARN in KVM's mmu_notifier. In the past, empty ranges
have been diagnosed to be off-by-one bugs, hence the WARNing. Given the
low (so far) number of unique reports, the benefits of detecting more
buggy callers seem to outweigh the cost of having to fix cases such as
this one, where userspace is doing something silly. In this particular
case, an early return from move_page_tables() is enough to fix the
issue.
In the Linux kernel, the following vulnerability has been resolved:
gpio: Restrict usage of GPIO chip irq members before initialization
GPIO chip irq members are exposed before they could be completely
initialized and this leads to race conditions.
One such issue was observed for the gc->irq.domain variable which
was accessed through the I2C interface in gpiochip_to_irq() before
it could be initialized by gpiochip_add_irqchip(). This resulted in
Kernel NULL pointer dereference.
Following are the logs for reference :-
kernel: Call Trace:
kernel: gpiod_to_irq+0x53/0x70
kernel: acpi_dev_gpio_irq_get_by+0x113/0x1f0
kernel: i2c_acpi_get_irq+0xc0/0xd0
kernel: i2c_device_probe+0x28a/0x2a0
kernel: really_probe+0xf2/0x460
kernel: RIP: 0010:gpiochip_to_irq+0x47/0xc0
To avoid such scenarios, restrict usage of GPIO chip irq members before
they are completely initialized.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix qgroup reserve overflow the qgroup limit
We use extent_changeset->bytes_changed in qgroup_reserve_data() to record
how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the
bytes_changed is set as "unsigned int", and it will overflow if we try to
fallocate a range larger than 4GiB. The result is we reserve less bytes
and eventually break the qgroup limit.
Unlike regular buffered/direct write, which we use one changeset for
each ordered extent, which can never be larger than 256M. For
fallocate, we use one changeset for the whole range, thus it no longer
respects the 256M per extent limit, and caused the problem.
The following example test script reproduces the problem:
$ cat qgroup-overflow.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
# Set qgroup limit to 2GiB.
btrfs quota enable $MNT
btrfs qgroup limit 2G $MNT
# Try to fallocate a 3GiB file. This should fail.
echo
echo "Try to fallocate a 3GiB file..."
fallocate -l 3G $MNT/3G.file
# Try to fallocate a 5GiB file.
echo
echo "Try to fallocate a 5GiB file..."
fallocate -l 5G $MNT/5G.file
# See we break the qgroup limit.
echo
sync
btrfs qgroup show -r $MNT
umount $MNT
When running the test:
$ ./qgroup-overflow.sh
(...)
Try to fallocate a 3GiB file...
fallocate: fallocate failed: Disk quota exceeded
Try to fallocate a 5GiB file...
qgroupid rfer excl max_rfer
-------- ---- ---- --------
0/5 5.00GiB 5.00GiB 2.00GiB
Since we have no control of how bytes_changed is used, it's better to
set it to u64.
In the Linux kernel, the following vulnerability has been resolved:
powerpc: Fix virt_addr_valid() for 64-bit Book3E & 32-bit
mpe: On 64-bit Book3E vmalloc space starts at 0x8000000000000000.
Because of the way __pa() works we have:
__pa(0x8000000000000000) == 0, and therefore
virt_to_pfn(0x8000000000000000) == 0, and therefore
virt_addr_valid(0x8000000000000000) == true
Which is wrong, virt_addr_valid() should be false for vmalloc space.
In fact all vmalloc addresses that alias with a valid PFN will return
true from virt_addr_valid(). That can cause bugs with hardened usercopy
as described below by Kefeng Wang:
When running ethtool eth0 on 64-bit Book3E, a BUG occurred:
usercopy: Kernel memory exposure attempt detected from SLUB object not in SLUB page?! (offset 0, size 1048)!
kernel BUG at mm/usercopy.c:99
...
usercopy_abort+0x64/0xa0 (unreliable)
__check_heap_object+0x168/0x190
__check_object_size+0x1a0/0x200
dev_ethtool+0x2494/0x2b20
dev_ioctl+0x5d0/0x770
sock_do_ioctl+0xf0/0x1d0
sock_ioctl+0x3ec/0x5a0
__se_sys_ioctl+0xf0/0x160
system_call_exception+0xfc/0x1f0
system_call_common+0xf8/0x200
The code shows below,
data = vzalloc(array_size(gstrings.len, ETH_GSTRING_LEN));
copy_to_user(useraddr, data, gstrings.len * ETH_GSTRING_LEN))
The data is alloced by vmalloc(), virt_addr_valid(ptr) will return true
on 64-bit Book3E, which leads to the panic.
As commit 4dd7554a6456 ("powerpc/64: Add VIRTUAL_BUG_ON checks for __va
and __pa addresses") does, make sure the virt addr above PAGE_OFFSET in
the virt_addr_valid() for 64-bit, also add upper limit check to make
sure the virt is below high_memory.
Meanwhile, for 32-bit PAGE_OFFSET is the virtual address of the start
of lowmem, high_memory is the upper low virtual address, the check is
suitable for 32-bit, this will fix the issue mentioned in commit
602946ec2f90 ("powerpc: Set max_mapnr correctly") too.
On 32-bit there is a similar problem with high memory, that was fixed in
commit 602946ec2f90 ("powerpc: Set max_mapnr correctly"), but that
commit breaks highmem and needs to be reverted.
We can't easily fix __pa(), we have code that relies on its current
behaviour. So for now add extra checks to virt_addr_valid().
For 64-bit Book3S the extra checks are not necessary, the combination of
virt_to_pfn() and pfn_valid() should yield the correct result, but they
are harmless.
[mpe: Add additional change log detail]
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: tcmu: Fix possible page UAF
tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not
take refcount properly and just returns page pointer. When
tcmu_try_get_data_page() returns, the returned page may have been freed by
tcmu_blocks_release().
We need to get_page() under cmdr_lock to avoid concurrent
tcmu_blocks_release().