In the Linux kernel, the following vulnerability has been resolved:
minix: Add required sanity checking to minix_check_superblock()
The fs/minix implementation of the minix filesystem does not currently
support any other value for s_log_zone_size than 0. This is also the
only value supported in util-linux; see mkfs.minix.c line 511. In
addition, this patch adds some sanity checking for the other minix
superblock fields, and moves the minix_blocks_needed() checks for the
zmap and imap also to minix_check_super_block().
This also closes a related syzbot bug report.
In the Linux kernel, the following vulnerability has been resolved:
tracing: ring-buffer: Fix to check event length before using
Check the event length before adding it for accessing next index in
rb_read_data_buffer(). Since this function is used for validating
possibly broken ring buffers, the length of the event could be broken.
In that case, the new event (e + len) can point a wrong address.
To avoid invalid memory access at boot, check whether the length of
each event is in the possible range before using it.
In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix pci_slot_trylock() error handling
Commit a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()")
delegates the bridge device's pci_dev_trylock() to pci_bus_trylock() in
pci_slot_trylock(), but it forgets to remove the corresponding
pci_dev_unlock() when pci_bus_trylock() fails.
Before a4e772898f8b, the code did:
if (!pci_dev_trylock(dev)) /* <- lock bridge device */
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev); /* <- unlock bridge device */
goto unlock;
}
}
After a4e772898f8b the bridge-device lock is no longer taken, but the
pci_dev_unlock(dev) on the failure path was left in place, leading to the
bug.
This yields one of two errors:
1. A warning that the lock is being unlocked when no one holds it.
2. An incorrect unlock of a lock that belongs to another thread.
Fix it by removing the now-redundant pci_dev_unlock(dev) on the failure
path.
[Same patch later posted by Keith at
https://patch.msgid.link/20260116184150.3013258-1-kbusch@meta.com]
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Make cpumask_of_node() robust against NUMA_NO_NODE
The arch definition of cpumask_of_node() cannot handle NUMA_NO_NODE -
which is a valid index - so add a check for this.
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()
Add SRCU read-side protection when reading PDPTR registers in
__get_sregs2().
Reading PDPTRs may trigger access to guest memory:
kvm_pdptr_read() -> svm_cache_reg() -> load_pdptrs() ->
kvm_vcpu_read_guest_page() -> kvm_vcpu_gfn_to_memslot()
kvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(),
which uses srcu_dereference_check() and requires either kvm->srcu or
kvm->slots_lock to be held. Currently only vcpu->mutex is held,
triggering lockdep warning:
=============================
WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot
6.12.59+ #3 Not tainted
include/linux/kvm_host.h:1062 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.5.1717/15100:
#0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824
__kvm_memslots include/linux/kvm_host.h:1062 [inline]
__kvm_memslots include/linux/kvm_host.h:1059 [inline]
kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline]
kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617
kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302
load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065
svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688
kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline]
__get_sregs2 arch/x86/kvm/x86.c:11784 [inline]
kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279
kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
PCI: endpoint: Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions
struct configfs_item_operations callbacks are defined like the following:
int (*allow_link)(struct config_item *src, struct config_item *target);
void (*drop_link)(struct config_item *src, struct config_item *target);
While pci_primary_epc_epf_link() and pci_secondary_epc_epf_link() specify
the parameters in the correct order, pci_primary_epc_epf_unlink() and
pci_secondary_epc_epf_unlink() specify the parameters in the wrong order,
leading to the below kernel crash when using the unlink command in
configfs:
Unable to handle kernel paging request at virtual address 0000000300000857
Mem abort info:
...
pc : string+0x54/0x14c
lr : vsnprintf+0x280/0x6e8
...
string+0x54/0x14c
vsnprintf+0x280/0x6e8
vprintk_default+0x38/0x4c
vprintk+0xc4/0xe0
pci_epf_unbind+0xdc/0x108
configfs_unlink+0xe0/0x208+0x44/0x74
vfs_unlink+0x120/0x29c
__arm64_sys_unlinkat+0x3c/0x90
invoke_syscall+0x48/0x134
do_el0_svc+0x1c/0x30prop.0+0xd0/0xf0
[mani: cced stable, changed commit message as per https://lore.kernel.org/linux-pci/aV9joi3jF1R6ca02@ryzen]
In the Linux kernel, the following vulnerability has been resolved:
APEI/GHES: ARM processor Error: don't go past allocated memory
If the BIOS generates a very small ARM Processor Error, or
an incomplete one, the current logic will fail to deferrence
err->section_length
and
ctx_info->size
Add checks to avoid that. With such changes, such GHESv2
records won't cause OOPSes like this:
[ 1.492129] Internal error: Oops: 0000000096000005 [#1] SMP
[ 1.495449] Modules linked in:
[ 1.495820] CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.18.0-rc1-00017-gabadcc3553dd-dirty #18 PREEMPT
[ 1.496125] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 02/02/2022
[ 1.496433] Workqueue: kacpi_notify acpi_os_execute_deferred
[ 1.496967] pstate: 814000c5 (Nzcv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[ 1.497199] pc : log_arm_hw_error+0x5c/0x200
[ 1.497380] lr : ghes_handle_arm_hw_error+0x94/0x220
0xffff8000811c5324 is in log_arm_hw_error (../drivers/ras/ras.c:75).
70 err_info = (struct cper_arm_err_info *)(err + 1);
71 ctx_info = (struct cper_arm_ctx_info *)(err_info + err->err_info_num);
72 ctx_err = (u8 *)ctx_info;
73
74 for (n = 0; n < err->context_info_num; n++) {
75 sz = sizeof(struct cper_arm_ctx_info) + ctx_info->size;
76 ctx_info = (struct cper_arm_ctx_info *)((long)ctx_info + sz);
77 ctx_len += sz;
78 }
79
and similar ones while trying to access section_length on an
error dump with too small size.
[ rjw: Subject tweaks ]
In the Linux kernel, the following vulnerability has been resolved:
fbdev: vt8500lcdfb: fix missing dma_free_coherent()
fbi->fb.screen_buffer is allocated with dma_alloc_coherent() but is not
freed if the error path is reached.
In the Linux kernel, the following vulnerability has been resolved:
atm: fore200e: fix use-after-free in tasklets during device removal
When the PCA-200E or SBA-200E adapter is being detached, the fore200e
is deallocated. However, the tx_tasklet or rx_tasklet may still be running
or pending, leading to use-after-free bug when the already freed fore200e
is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet().
One of the race conditions can occur as follows:
CPU 0 (cleanup) | CPU 1 (tasklet)
fore200e_pca_remove_one() | fore200e_interrupt()
fore200e_shutdown() | tasklet_schedule()
kfree(fore200e) | fore200e_tx_tasklet()
| fore200e-> // UAF
Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before
the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to
synchronize with any pending or running tasklets. Moreover, since
fore200e_reset() could prevent further interrupts or data transfers,
the tasklet_kill() should be placed after fore200e_reset() to prevent
the tasklet from being rescheduled in fore200e_interrupt(). Finally,
it only needs to do tasklet_kill() when the fore200e state is greater
than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized
in earlier states. In a word, the tasklet_kill() should be placed in
the FORE200E_STATE_IRQ branch within the switch...case structure.
This bug was identified through static analysis.