In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Tear down vGIC on failed vCPU creation
If kvm_arch_vcpu_create() fails to share the vCPU page with the
hypervisor, we propagate the error back to the ioctl but leave the
vGIC vCPU data initialised. Note only does this leak the corresponding
memory when the vCPU is destroyed but it can also lead to use-after-free
if the redistributor device handling tries to walk into the vCPU.
Add the missing cleanup to kvm_arch_vcpu_create(), ensuring that the
vGIC vCPU structures are destroyed on error.
In the Linux kernel, the following vulnerability has been resolved:
pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()
With CONFIG_COMPILE_TEST && !CONFIG_HAVE_CLK, pwm_mediatek_config() has a
divide-by-zero in the following line:
do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
due to the fact that the !CONFIG_HAVE_CLK version of clk_get_rate()
returns zero.
This is presumably just a theoretical problem: COMPILE_TEST overrides
the dependency on RALINK which would select COMMON_CLK. Regardless it's
a good idea to check for the error explicitly to avoid divide-by-zero.
Fixes the following warning:
drivers/pwm/pwm-mediatek.o: warning: objtool: .text: unexpected end of section
[ukleinek: s/CONFIG_CLK/CONFIG_HAVE_CLK/]
In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix reference leak in pci_register_host_bridge()
If device_register() fails, call put_device() to give up the reference to
avoid a memory leak, per the comment at device_register().
Found by code review.
[bhelgaas: squash Dan Carpenter's double free fix from
https://lore.kernel.org/r/db806a6c-a91b-4e5a-a84b-6b7e01bdac85@stanley.mountain]
In the Linux kernel, the following vulnerability has been resolved:
jbd2: remove wrong sb->s_sequence check
Journal emptiness is not determined by sb->s_sequence == 0 but rather by
sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a
valid transaction ID so the check can spuriously trigger. Remove the
invalid WARN_ON.
In the Linux kernel, the following vulnerability has been resolved:
pm: cpupower: bench: Prevent NULL dereference on malloc failure
If malloc returns NULL due to low memory, 'config' pointer can be NULL.
Add a check to prevent NULL dereference.
In the Linux kernel, the following vulnerability has been resolved:
spi: fsl-qspi: use devm function instead of driver remove
Driver use devm APIs to manage clk/irq/resources and register the spi
controller, but the legacy remove function will be called first during
device detach and trigger kernel panic. Drop the remove function and use
devm_add_action_or_reset() for driver cleanup to ensure the release
sequence.
Trigger kernel panic on i.MX8MQ by
echo 30bb0000.spi >/sys/bus/platform/drivers/fsl-quadspi/unbind
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: scpi: Fix null-ptr-deref in scpi_cpufreq_get_rate()
cpufreq_cpu_get_raw() can return NULL when the target CPU is not present
in the policy->cpus mask. scpi_cpufreq_get_rate() does not check for
this case, which results in a NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: scmi: Fix null-ptr-deref in scmi_cpufreq_get_rate()
cpufreq_cpu_get_raw() can return NULL when the target CPU is not present
in the policy->cpus mask. scmi_cpufreq_get_rate() does not check for
this case, which results in a NULL pointer dereference.
Add NULL check after cpufreq_cpu_get_raw() to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved:
mm/vmscan: don't try to reclaim hwpoison folio
Syzkaller reports a bug as follows:
Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000
Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users
Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed
page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e
memcg:ffff0000dd6d9000
anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff)
raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9
raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000
page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio))
------------[ cut here ]------------
kernel BUG at mm/swap_state.c:184!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Modules linked in:
CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3
Hardware name: linux,dummy-virt (DT)
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : add_to_swap+0xbc/0x158
lr : add_to_swap+0xbc/0x158
sp : ffff800087f37340
x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780
x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0
x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4
x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000
x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c
x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b
x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000
x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001
x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000
Call trace:
add_to_swap+0xbc/0x158
shrink_folio_list+0x12ac/0x2648
shrink_inactive_list+0x318/0x948
shrink_lruvec+0x450/0x720
shrink_node_memcgs+0x280/0x4a8
shrink_node+0x128/0x978
balance_pgdat+0x4f0/0xb20
kswapd+0x228/0x438
kthread+0x214/0x230
ret_from_fork+0x10/0x20
I can reproduce this issue with the following steps:
1) When a dirty swapcache page is isolated by reclaim process and the
page isn't locked, inject memory failure for the page.
me_swapcache_dirty() clears uptodate flag and tries to delete from lru,
but fails. Reclaim process will put the hwpoisoned page back to lru.
2) The process that maps the hwpoisoned page exits, the page is deleted
the page will never be freed and will be in the lru forever.
3) If we trigger a reclaim again and tries to reclaim the page,
add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is
cleared.
To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the
hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap
it in shrink_folio_list(), otherwise the folio will fail to be unmaped by
hwpoison_user_mappings() since the folio isn't in lru list.