Security Vulnerabilities
- CVEs Published In May 2024
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Fix slab-use-after-free in gfs2_qd_dealloc
In gfs2_put_super(), whether withdrawn or not, the quota should
be cleaned up by gfs2_quota_cleanup().
Otherwise, struct gfs2_sbd will be freed before gfs2_qd_dealloc (rcu
callback) has run for all gfs2_quota_data objects, resulting in
use-after-free.
Also, gfs2_destroy_threads() and gfs2_quota_cleanup() is already called
by gfs2_make_fs_ro(), so in gfs2_put_super(), after calling
gfs2_make_fs_ro(), there is no need to call them again.
In the Linux kernel, the following vulnerability has been resolved:
riscv: VMAP_STACK overflow detection thread-safe
commit 31da94c25aea ("riscv: add VMAP_STACK overflow detection") added
support for CONFIG_VMAP_STACK. If overflow is detected, CPU switches to
`shadow_stack` temporarily before switching finally to per-cpu
`overflow_stack`.
If two CPUs/harts are racing and end up in over flowing kernel stack, one
or both will end up corrupting each other state because `shadow_stack` is
not per-cpu. This patch optimizes per-cpu overflow stack switch by
directly picking per-cpu `overflow_stack` and gets rid of `shadow_stack`.
Following are the changes in this patch
- Defines an asm macro to obtain per-cpu symbols in destination
register.
- In entry.S, when overflow is detected, per-cpu overflow stack is
located using per-cpu asm macro. Computing per-cpu symbol requires
a temporary register. x31 is saved away into CSR_SCRATCH
(CSR_SCRATCH is anyways zero since we're in kernel).
Please see Links for additional relevant disccussion and alternative
solution.
Tested by `echo EXHAUST_STACK > /sys/kernel/debug/provoke-crash/DIRECT`
Kernel crash log below
Insufficient stack space to handle exception!/debug/provoke-crash/DIRECT
Task stack: [0xff20000010a98000..0xff20000010a9c000]
Overflow stack: [0xff600001f7d98370..0xff600001f7d99370]
CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34
Hardware name: riscv-virtio,qemu (DT)
epc : __memset+0x60/0xfc
ra : recursive_loop+0x48/0xc6 [lkdtm]
epc : ffffffff808de0e4 ra : ffffffff0163a752 sp : ff20000010a97e80
gp : ffffffff815c0330 tp : ff600000820ea280 t0 : ff20000010a97e88
t1 : 000000000000002e t2 : 3233206874706564 s0 : ff20000010a982b0
s1 : 0000000000000012 a0 : ff20000010a97e88 a1 : 0000000000000000
a2 : 0000000000000400 a3 : ff20000010a98288 a4 : 0000000000000000
a5 : 0000000000000000 a6 : fffffffffffe43f0 a7 : 00007fffffffffff
s2 : ff20000010a97e88 s3 : ffffffff01644680 s4 : ff20000010a9be90
s5 : ff600000842ba6c0 s6 : 00aaaaaac29e42b0 s7 : 00fffffff0aa3684
s8 : 00aaaaaac2978040 s9 : 0000000000000065 s10: 00ffffff8a7cad10
s11: 00ffffff8a76a4e0 t3 : ffffffff815dbaf4 t4 : ffffffff815dbaf4
t5 : ffffffff815dbab8 t6 : ff20000010a9bb48
status: 0000000200000120 badaddr: ff20000010a97e88 cause: 000000000000000f
Kernel panic - not syncing: Kernel stack overflow
CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80006754>] dump_backtrace+0x30/0x38
[<ffffffff808de798>] show_stack+0x40/0x4c
[<ffffffff808ea2a8>] dump_stack_lvl+0x44/0x5c
[<ffffffff808ea2d8>] dump_stack+0x18/0x20
[<ffffffff808dec06>] panic+0x126/0x2fe
[<ffffffff800065ea>] walk_stackframe+0x0/0xf0
[<ffffffff0163a752>] recursive_loop+0x48/0xc6 [lkdtm]
SMP: stopping secondary CPUs
---[ end Kernel panic - not syncing: Kernel stack overflow ]---
In the Linux kernel, the following vulnerability has been resolved:
virtio-blk: fix implicit overflow on virtio_max_dma_size
The following codes have an implicit conversion from size_t to u32:
(u32)max_size = (size_t)virtio_max_dma_size(vdev);
This may lead overflow, Ex (size_t)4G -> (u32)0. Once
virtio_max_dma_size() has a larger size than U32_MAX, use U32_MAX
instead.
In the Linux kernel, the following vulnerability has been resolved:
i3c: master: mipi-i3c-hci: Fix a kernel panic for accessing DAT_data.
The `i3c_master_bus_init` function may attach the I2C devices before the
I3C bus initialization. In this flow, the DAT `alloc_entry`` will be used
before the DAT `init`. Additionally, if the `i3c_master_bus_init` fails,
the DAT `cleanup` will execute before the device is detached, which will
execue DAT `free_entry` function. The above scenario can cause the driver
to use DAT_data when it is NULL.
In the Linux kernel, the following vulnerability has been resolved:
media: gspca: cpia1: shift-out-of-bounds in set_flicker
Syzkaller reported the following issue:
UBSAN: shift-out-of-bounds in drivers/media/usb/gspca/cpia1.c:1031:27
shift exponent 245 is too large for 32-bit type 'int'
When the value of the variable "sd->params.exposure.gain" exceeds the
number of bits in an integer, a shift-out-of-bounds error is reported. It
is triggered because the variable "currentexp" cannot be left-shifted by
more than the number of bits in an integer. In order to avoid invalid
range during left-shift, the conditional expression is added.
In the Linux kernel, the following vulnerability has been resolved:
mfd: qcom-spmi-pmic: Fix revid implementation
The Qualcomm SPMI PMIC revid implementation is broken in multiple ways.
First, it assumes that just because the sibling base device has been
registered that means that it is also bound to a driver, which may not
be the case (e.g. due to probe deferral or asynchronous probe). This
could trigger a NULL-pointer dereference when attempting to access the
driver data of the unbound device.
Second, it accesses driver data of a sibling device directly and without
any locking, which means that the driver data may be freed while it is
being accessed (e.g. on driver unbind).
Third, it leaks a struct device reference to the sibling device which is
looked up using the spmi_device_from_of() every time a function (child)
device is calling the revid function (e.g. on probe).
Fix this mess by reimplementing the revid lookup so that it is done only
at probe of the PMIC device; the base device fetches the revid info from
the hardware, while any secondary SPMI device fetches the information
from the base device and caches it so that it can be accessed safely
from its children. If the base device has not been probed yet then probe
of a secondary device is deferred.
In the Linux kernel, the following vulnerability has been resolved:
i3c: mipi-i3c-hci: Fix out of bounds access in hci_dma_irq_handler
Do not loop over ring headers in hci_dma_irq_handler() that are not
allocated and enabled in hci_dma_init(). Otherwise out of bounds access
will occur from rings->headers[i] access when i >= number of allocated
ring headers.
In the Linux kernel, the following vulnerability has been resolved:
tls: fix NULL deref on tls_sw_splice_eof() with empty record
syzkaller discovered that if tls_sw_splice_eof() is executed as part of
sendfile() when the plaintext/ciphertext sk_msg are empty, the send path
gets confused because the empty ciphertext buffer does not have enough
space for the encryption overhead. This causes tls_push_record() to go on
the `split = true` path (which is only supposed to be used when interacting
with an attached BPF program), and then get further confused and hit the
tls_merge_open_record() path, which then assumes that there must be at
least one populated buffer element, leading to a NULL deref.
It is possible to have empty plaintext/ciphertext buffers if we previously
bailed from tls_sw_sendmsg_locked() via the tls_trim_both_msgs() path.
tls_sw_push_pending_record() already handles this case correctly; let's do
the same check in tls_sw_splice_eof().
In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: use vmm_table as array in wilc struct
Enabling KASAN and running some iperf tests raises some memory issues with
vmm_table:
BUG: KASAN: slab-out-of-bounds in wilc_wlan_handle_txq+0x6ac/0xdb4
Write of size 4 at addr c3a61540 by task wlan0-tx/95
KASAN detects that we are writing data beyond range allocated to vmm_table.
There is indeed a mismatch between the size passed to allocator in
wilc_wlan_init, and the range of possible indexes used later: allocation
size is missing a multiplication by sizeof(u32)
In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix use-after-free in rdata->read_into_pages()
When the network status is unstable, use-after-free may occur when
read data from the server.
BUG: KASAN: use-after-free in readpages_fill_pages+0x14c/0x7e0
Call Trace:
<TASK>
dump_stack_lvl+0x38/0x4c
print_report+0x16f/0x4a6
kasan_report+0xb7/0x130
readpages_fill_pages+0x14c/0x7e0
cifs_readv_receive+0x46d/0xa40
cifs_demultiplex_thread+0x121c/0x1490
kthread+0x16b/0x1a0
ret_from_fork+0x2c/0x50
</TASK>
Allocated by task 2535:
kasan_save_stack+0x22/0x50
kasan_set_track+0x25/0x30
__kasan_kmalloc+0x82/0x90
cifs_readdata_direct_alloc+0x2c/0x110
cifs_readdata_alloc+0x2d/0x60
cifs_readahead+0x393/0xfe0
read_pages+0x12f/0x470
page_cache_ra_unbounded+0x1b1/0x240
filemap_get_pages+0x1c8/0x9a0
filemap_read+0x1c0/0x540
cifs_strict_readv+0x21b/0x240
vfs_read+0x395/0x4b0
ksys_read+0xb8/0x150
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Freed by task 79:
kasan_save_stack+0x22/0x50
kasan_set_track+0x25/0x30
kasan_save_free_info+0x2e/0x50
__kasan_slab_free+0x10e/0x1a0
__kmem_cache_free+0x7a/0x1a0
cifs_readdata_release+0x49/0x60
process_one_work+0x46c/0x760
worker_thread+0x2a4/0x6f0
kthread+0x16b/0x1a0
ret_from_fork+0x2c/0x50
Last potentially related work creation:
kasan_save_stack+0x22/0x50
__kasan_record_aux_stack+0x95/0xb0
insert_work+0x2b/0x130
__queue_work+0x1fe/0x660
queue_work_on+0x4b/0x60
smb2_readv_callback+0x396/0x800
cifs_abort_connection+0x474/0x6a0
cifs_reconnect+0x5cb/0xa50
cifs_readv_from_socket.cold+0x22/0x6c
cifs_read_page_from_socket+0xc1/0x100
readpages_fill_pages.cold+0x2f/0x46
cifs_readv_receive+0x46d/0xa40
cifs_demultiplex_thread+0x121c/0x1490
kthread+0x16b/0x1a0
ret_from_fork+0x2c/0x50
The following function calls will cause UAF of the rdata pointer.
readpages_fill_pages
cifs_read_page_from_socket
cifs_readv_from_socket
cifs_reconnect
__cifs_reconnect
cifs_abort_connection
mid->callback() --> smb2_readv_callback
queue_work(&rdata->work) # if the worker completes first,
# the rdata is freed
cifs_readv_complete
kref_put
cifs_readdata_release
kfree(rdata)
return rdata->... # UAF in readpages_fill_pages()
Similarly, this problem also occurs in the uncache_fill_pages().
Fix this by adjusts the order of condition judgment in the return
statement.