In the Linux kernel, the following vulnerability has been resolved:
cxl/acpi: Fix a use-after-free in cxl_parse_cfmws()
KASAN and KFENCE detected an user-after-free in the CXL driver. This
happens in the cxl_decoder_add() fail path. KASAN prints the following
error:
BUG: KASAN: slab-use-after-free in cxl_parse_cfmws (drivers/cxl/acpi.c:299)
This happens in cxl_parse_cfmws(), where put_device() is called,
releasing cxld, which is accessed later.
Use the local variables in the dev_err() instead of pointing to the
released memory. Since the dev_err() is printing a resource, change the open
coded print format to use the %pr format specifier.
In the Linux kernel, the following vulnerability has been resolved:
kobject: Add sanity check for kset->kobj.ktype in kset_register()
When I register a kset in the following way:
static struct kset my_kset;
kobject_set_name(&my_kset.kobj, "my_kset");
ret = kset_register(&my_kset);
A null pointer dereference exception is occurred:
[ 4453.568337] Unable to handle kernel NULL pointer dereference at \
virtual address 0000000000000028
... ...
[ 4453.810361] Call trace:
[ 4453.813062] kobject_get_ownership+0xc/0x34
[ 4453.817493] kobject_add_internal+0x98/0x274
[ 4453.822005] kset_register+0x5c/0xb4
[ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset]
... ...
Because I didn't initialize my_kset.kobj.ktype.
According to the description in Documentation/core-api/kobject.rst:
- A ktype is the type of object that embeds a kobject. Every structure
that embeds a kobject needs a corresponding ktype.
So add sanity check to make sure kset->kobj.ktype is not NULL.
In the Linux kernel, the following vulnerability has been resolved:
ubi: ubi_wl_put_peb: Fix infinite loop when wear-leveling work failed
Following process will trigger an infinite loop in ubi_wl_put_peb():
ubifs_bgt ubi_bgt
ubifs_leb_unmap
ubi_leb_unmap
ubi_eba_unmap_leb
ubi_wl_put_peb wear_leveling_worker
e1 = rb_entry(rb_first(&ubi->used)
e2 = get_peb_for_wl(ubi)
ubi_io_read_vid_hdr // return err (flash fault)
out_error:
ubi->move_from = ubi->move_to = NULL
wl_entry_destroy(ubi, e1)
ubi->lookuptbl[e->pnum] = NULL
retry:
e = ubi->lookuptbl[pnum]; // return NULL
if (e == ubi->move_from) { // NULL == NULL gets true
goto retry; // infinite loop !!!
$ top
PID USER PR NI VIRT RES SHR S %CPU %MEM COMMAND
7676 root 20 0 0 0 0 R 100.0 0.0 ubifs_bgt0_0
Fix it by:
1) Letting ubi_wl_put_peb() returns directly if wearl leveling entry has
been removed from 'ubi->lookuptbl'.
2) Using 'ubi->wl_lock' protecting wl entry deletion to preventing an
use-after-free problem for wl entry in ubi_wl_put_peb().
Fetch a reproducer in [Link].
In the Linux kernel, the following vulnerability has been resolved:
iommu: Fix error unwind in iommu_group_alloc()
If either iommu_group_grate_file() fails then the
iommu_group is leaked.
Destroy it on these error paths.
Found by kselftest/iommu/iommufd_fail_nth
In the Linux kernel, the following vulnerability has been resolved:
ionic: catch failure from devlink_alloc
Add a check for NULL on the alloc return. If devlink_alloc() fails and
we try to use devlink_priv() on the NULL return, the kernel gets very
unhappy and panics. With this fix, the driver load will still fail,
but at least it won't panic the kernel.
In the Linux kernel, the following vulnerability has been resolved:
pwm: lpc32xx: Remove handling of PWM channels
Because LPC32xx PWM controllers have only a single output which is
registered as the only PWM device/channel per controller, it is known in
advance that pwm->hwpwm value is always 0. On basis of this fact
simplify the code by removing operations with pwm->hwpwm, there is no
controls which require channel number as input.
Even though I wasn't aware at the time when I forward ported that patch,
this fixes a null pointer dereference as lpc32xx->chip.pwms is NULL
before devm_pwmchip_add() is called.
In the Linux kernel, the following vulnerability has been resolved:
ext4: improve error handling from ext4_dirhash()
The ext4_dirhash() will *almost* never fail, especially when the hash
tree feature was first introduced. However, with the addition of
support of encrypted, casefolded file names, that function can most
certainly fail today.
So make sure the callers of ext4_dirhash() properly check for
failures, and reflect the errors back up to their callers.
In the Linux kernel, the following vulnerability has been resolved:
x86/MCE/AMD: Use an u64 for bank_map
Thee maximum number of MCA banks is 64 (MAX_NR_BANKS), see
a0bc32b3cacf ("x86/mce: Increase maximum number of banks to 64").
However, the bank_map which contains a bitfield of which banks to
initialize is of type unsigned int and that overflows when those bit
numbers are >= 32, leading to UBSAN complaining correctly:
UBSAN: shift-out-of-bounds in arch/x86/kernel/cpu/mce/amd.c:1365:38
shift exponent 32 is too large for 32-bit type 'int'
Change the bank_map to a u64 and use the proper BIT_ULL() macro when
modifying bits in there.
[ bp: Rewrite commit message. ]
In the Linux kernel, the following vulnerability has been resolved:
usb: xhci: tegra: fix sleep in atomic call
When we set the dual-role port to Host mode, we observed the following
splat:
[ 167.057718] BUG: sleeping function called from invalid context at
include/linux/sched/mm.h:229
[ 167.057872] Workqueue: events tegra_xusb_usb_phy_work
[ 167.057954] Call trace:
[ 167.057962] dump_backtrace+0x0/0x210
[ 167.057996] show_stack+0x30/0x50
[ 167.058020] dump_stack_lvl+0x64/0x84
[ 167.058065] dump_stack+0x14/0x34
[ 167.058100] __might_resched+0x144/0x180
[ 167.058140] __might_sleep+0x64/0xd0
[ 167.058171] slab_pre_alloc_hook.constprop.0+0xa8/0x110
[ 167.058202] __kmalloc_track_caller+0x74/0x2b0
[ 167.058233] kvasprintf+0xa4/0x190
[ 167.058261] kasprintf+0x58/0x90
[ 167.058285] tegra_xusb_find_port_node.isra.0+0x58/0xd0
[ 167.058334] tegra_xusb_find_port+0x38/0xa0
[ 167.058380] tegra_xusb_padctl_get_usb3_companion+0x38/0xd0
[ 167.058430] tegra_xhci_id_notify+0x8c/0x1e0
[ 167.058473] notifier_call_chain+0x88/0x100
[ 167.058506] atomic_notifier_call_chain+0x44/0x70
[ 167.058537] tegra_xusb_usb_phy_work+0x60/0xd0
[ 167.058581] process_one_work+0x1dc/0x4c0
[ 167.058618] worker_thread+0x54/0x410
[ 167.058650] kthread+0x188/0x1b0
[ 167.058672] ret_from_fork+0x10/0x20
The function tegra_xusb_padctl_get_usb3_companion eventually calls
tegra_xusb_find_port and this in turn calls kasprintf which might sleep
and so cannot be called from an atomic context.
Fix this by moving the call to tegra_xusb_padctl_get_usb3_companion to
the tegra_xhci_id_work function where it is really needed.