In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: display: Fix refcount leak bug
In omapdss_init_fbdev(), of_find_node_by_name() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: pdata-quirks: Fix refcount leak bug
In pdata_quirks_init_clocks(), the loop contains
of_find_node_by_name() but without corresponding of_node_put().
In the Linux kernel, the following vulnerability has been resolved:
ext2: Add more validity checks for inode counts
Add checks verifying number of inodes stored in the superblock matches
the number computed from number of inodes per group. Also verify we have
at least one block worth of inodes per group. This prevents crashes on
corrupted filesystems.
In the Linux kernel, the following vulnerability has been resolved:
arm64: fix oops in concurrently setting insn_emulation sysctls
emulation_proc_handler() changes table->data for proc_dointvec_minmax
and can generate the following Oops if called concurrently with itself:
| Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
| Internal error: Oops: 96000006 [#1] SMP
| Call trace:
| update_insn_emulation_mode+0xc0/0x148
| emulation_proc_handler+0x64/0xb8
| proc_sys_call_handler+0x9c/0xf8
| proc_sys_write+0x18/0x20
| __vfs_write+0x20/0x48
| vfs_write+0xe4/0x1d0
| ksys_write+0x70/0xf8
| __arm64_sys_write+0x20/0x28
| el0_svc_common.constprop.0+0x7c/0x1c0
| el0_svc_handler+0x2c/0xa0
| el0_svc+0x8/0x200
To fix this issue, keep the table->data as &insn->current_mode and
use container_of() to retrieve the insn pointer. Another mutex is
used to protect against the current_mode update but not for retrieving
insn_emulation as table->data is no longer changing.
In the Linux kernel, the following vulnerability has been resolved:
ARM: bcm: Fix refcount leak in bcm_kona_smc_init
of_find_matching_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.
In the Linux kernel, the following vulnerability has been resolved:
selinux: Add boundary check in put_entry()
Just like next_entry(), boundary check is necessary to prevent memory
out-of-bound access.
In the Linux kernel, the following vulnerability has been resolved:
PM: hibernate: defer device probing when resuming from hibernation
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.
When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.
There are three cases that can prevent probe_count from dropping to 0.
(a) A device being probed stopped responding (i.e. broken/malicious
hardware).
(b) A process emulating a USB device using /dev/raw-gadget interface
stopped responding for some reason.
(c) New device probe requests keeps coming in before existing device
probe requests complete.
The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.
This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).
Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: fix potential buffer overflow in ni_set_mc_special_registers()
The last case label can write two buffers 'mc_reg_address[j]' and
'mc_data[j]' with 'j' offset equal to SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE
since there are no checks for this value in both case labels after the
last 'j++'.
Instead of changing '>' to '>=' there, add the bounds check at the start
of the second 'case' (the first one already has it).
Also, remove redundant last checks for 'j' index bigger than array size.
The expression is always false. Moreover, before or after the patch
'table->last' can be equal to SMC_NISLANDS_MC_REGISTER_ARRAY_SIZE and it
seems it can be a valid value.
Detected using the static analysis tool - Svace.