Linux: >> Linux Kernel >> 2.1.6 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Use device rbtree in iopf reporting path
The existing I/O page fault handler currently locates the PCI device by
calling pci_get_domain_bus_and_slot(). This function searches the list
of all PCI devices until the desired device is found. To improve lookup
efficiency, replace it with device_rbtree_find() to search the device
within the probed device rbtree.
The I/O page fault is initiated by the device, which does not have any
synchronization mechanism with the software to ensure that the device
stays in the probed device tree. Theoretically, a device could be released
by the IOMMU subsystem after device_rbtree_find() and before
iopf_get_dev_fault_param(), which would cause a use-after-free problem.
Add a mutex to synchronize the I/O page fault reporting path and the IOMMU
release device path. This lock doesn't introduce any performance overhead,
as the conflict between I/O page fault reporting and device releasing is
very rare.
CVSS Score
6.8
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix information leak in btrfs_ioctl_logical_to_ino()
Syzbot reported the following information leak for in
btrfs_ioctl_logical_to_ino():
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
_copy_to_user+0xbc/0x110 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:191 [inline]
btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Uninit was created at:
__kmalloc_large_node+0x231/0x370 mm/slub.c:3921
__do_kmalloc_node mm/slub.c:3954 [inline]
__kmalloc_node+0xb07/0x1060 mm/slub.c:3973
kmalloc_node include/linux/slab.h:648 [inline]
kvmalloc_node+0xc0/0x2d0 mm/util.c:634
kvmalloc include/linux/slab.h:766 [inline]
init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779
btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480
btrfs_ioctl+0x714/0x1260
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x261/0x450 fs/ioctl.c:890
__x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890
x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Bytes 40-65535 of 65536 are uninitialized
Memory access of size 65536 starts at ffff888045a40000
This happens, because we're copying a 'struct btrfs_data_container' back
to user-space. This btrfs_data_container is allocated in
'init_data_container()' via kvmalloc(), which does not zero-fill the
memory.
Fix this by using kvzalloc() which zeroes out the memory on allocation.
CVSS Score
7.1
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
usb: udc: remove warning when queue disabled ep
It is possible trigger below warning message from mass storage function,
WARNING: CPU: 6 PID: 3839 at drivers/usb/gadget/udc/core.c:294 usb_ep_queue+0x7c/0x104
pc : usb_ep_queue+0x7c/0x104
lr : fsg_main_thread+0x494/0x1b3c
Root cause is mass storage function try to queue request from main thread,
but other thread may already disable ep when function disable.
As there is no function failure in the driver, in order to avoid effort
to fix warning, change WARN_ON_ONCE() in usb_ep_queue() to pr_debug().
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
PCI/PM: Drain runtime-idle callbacks before driver removal
A race condition between the .runtime_idle() callback and the .remove()
callback in the rtsx_pcr PCI driver leads to a kernel crash due to an
unhandled page fault [1].
The problem is that rtsx_pci_runtime_idle() is not expected to be running
after pm_runtime_get_sync() has been called, but the latter doesn't really
guarantee that. It only guarantees that the suspend and resume callbacks
will not be running when it returns.
However, if a .runtime_idle() callback is already running when
pm_runtime_get_sync() is called, the latter will notice that the runtime PM
status of the device is RPM_ACTIVE and it will return right away without
waiting for the former to complete. In fact, it cannot wait for
.runtime_idle() to complete because it may be called from that callback (it
arguably does not make much sense to do that, but it is not strictly
prohibited).
Thus in general, whoever is providing a .runtime_idle() callback needs
to protect it from running in parallel with whatever code runs after
pm_runtime_get_sync(). [Note that .runtime_idle() will not start after
pm_runtime_get_sync() has returned, but it may continue running then if it
has started earlier.]
One way to address that race condition is to call pm_runtime_barrier()
after pm_runtime_get_sync() (not before it, because a nonzero value of the
runtime PM usage counter is necessary to prevent runtime PM callbacks from
being invoked) to wait for the .runtime_idle() callback to complete should
it be running at that point. A suitable place for doing that is in
pci_device_remove() which calls pm_runtime_get_sync() before removing the
driver, so it may as well call pm_runtime_barrier() subsequently, which
will prevent the race in question from occurring, not just in the rtsx_pcr
driver, but in any PCI drivers providing .runtime_idle() callbacks.
CVSS Score
4.7
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
x86/efistub: Call mixed mode boot services on the firmware's stack
Normally, the EFI stub calls into the EFI boot services using the stack
that was live when the stub was entered. According to the UEFI spec,
this stack needs to be at least 128k in size - this might seem large but
all asynchronous processing and event handling in EFI runs from the same
stack and so quite a lot of space may be used in practice.
In mixed mode, the situation is a bit different: the bootloader calls
the 32-bit EFI stub entry point, which calls the decompressor's 32-bit
entry point, where the boot stack is set up, using a fixed allocation
of 16k. This stack is still in use when the EFI stub is started in
64-bit mode, and so all calls back into the EFI firmware will be using
the decompressor's limited boot stack.
Due to the placement of the boot stack right after the boot heap, any
stack overruns have gone unnoticed. However, commit
5c4feadb0011983b ("x86/decompressor: Move global symbol references to C code")
moved the definition of the boot heap into C code, and now the boot
stack is placed right at the base of BSS, where any overruns will
corrupt the end of the .data section.
While it would be possible to work around this by increasing the size of
the boot stack, doing so would affect all x86 systems, and mixed mode
systems are a tiny (and shrinking) fraction of the x86 installed base.
So instead, record the firmware stack pointer value when entering from
the 32-bit firmware, and switch to this stack every time a EFI boot
service call is made.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
dm snapshot: fix lockup in dm_exception_table_exit
There was reported lockup when we exit a snapshot with many exceptions.
Fix this by adding "cond_resched" to the loop that frees the exceptions.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
net: atlantic: eliminate double free in error handling logic
Driver has a logic leak in ring data allocation/free,
where aq_ring_free could be called multiple times on same ring,
if system is under stress and got memory allocation error.
Ring pointer was used as an indicator of failure, but this is
not correct since only ring data is allocated/deallocated.
Ring itself is an array member.
Changing ring allocation functions to return error code directly.
This simplifies error handling and eliminates aq_ring_free
on higher layer.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock with fiemap and extent locking
While working on the patchset to remove extent locking I got a lockdep
splat with fiemap and pagefaulting with my new extent lock replacement
lock.
This deadlock exists with our normal code, we just don't have lockdep
annotations with the extent locking so we've never noticed it.
Since we're copying the fiemap extent to user space on every iteration
we have the chance of pagefaulting. Because we hold the extent lock for
the entire range we could mkwrite into a range in the file that we have
mmap'ed. This would deadlock with the following stack trace
[<0>] lock_extent+0x28d/0x2f0
[<0>] btrfs_page_mkwrite+0x273/0x8a0
[<0>] do_page_mkwrite+0x50/0xb0
[<0>] do_fault+0xc1/0x7b0
[<0>] __handle_mm_fault+0x2fa/0x460
[<0>] handle_mm_fault+0xa4/0x330
[<0>] do_user_addr_fault+0x1f4/0x800
[<0>] exc_page_fault+0x7c/0x1e0
[<0>] asm_exc_page_fault+0x26/0x30
[<0>] rep_movs_alternative+0x33/0x70
[<0>] _copy_to_user+0x49/0x70
[<0>] fiemap_fill_next_extent+0xc8/0x120
[<0>] emit_fiemap_extent+0x4d/0xa0
[<0>] extent_fiemap+0x7f8/0xad0
[<0>] btrfs_fiemap+0x49/0x80
[<0>] __x64_sys_ioctl+0x3e1/0xb50
[<0>] do_syscall_64+0x94/0x1a0
[<0>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
I wrote an fstest to reproduce this deadlock without my replacement lock
and verified that the deadlock exists with our existing locking.
To fix this simply don't take the extent lock for the entire duration of
the fiemap. This is safe in general because we keep track of where we
are when we're searching the tree, so if an ordered extent updates in
the middle of our fiemap call we'll still emit the correct extents
because we know what offset we were on before.
The only place we maintain the lock is searching delalloc. Since the
delalloc stuff can change during writeback we want to lock the extent
range so we have a consistent view of delalloc at the time we're
checking to see if we need to set the delalloc flag.
With this patch applied we no longer deadlock with my testcase.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-17
In the Linux kernel, the following vulnerability has been resolved:
usb: aqc111: check packet for fixup for true limit
If a device sends a packet that is inbetween 0
and sizeof(u64) the value passed to skb_trim()
as length will wrap around ending up as some very
large value.
The driver will then proceed to parse the header
located at that position, which will either oops or
process some random value.
The fix is to check against sizeof(u64) rather than
0, which the driver currently does. The issue exists
since the introduction of the driver.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-05-14
Linux Kernel Bluetooth CMTP Module Double Free Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute high-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the CMTP module. The issue results from the lack of validating the existence of an object prior to performing further free operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the kernel. Was ZDI-CAN-11977.
CVSS Score
7.5
EPSS Score
0.0
Published
2024-05-07