In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: make sure cache entry active before cache_show
The function `c_show` was called with protection from RCU. This only
ensures that `cp` will not be freed. Therefore, the reference count for
`cp` can drop to zero, which will trigger a refcount use-after-free
warning when `cache_get` is called. To resolve this issue, use
`cache_get_rcu` to ensure that `cp` remains active.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 7 PID: 822 at lib/refcount.c:25
refcount_warn_saturate+0xb1/0x120
CPU: 7 UID: 0 PID: 822 Comm: cat Not tainted 6.12.0-rc3+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
RIP: 0010:refcount_warn_saturate+0xb1/0x120
Call Trace:
<TASK>
c_show+0x2fc/0x380 [sunrpc]
seq_read_iter+0x589/0x770
seq_read+0x1e5/0x270
proc_reg_read+0xe1/0x140
vfs_read+0x125/0x530
ksys_read+0xc1/0x160
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the Linux kernel, the following vulnerability has been resolved:
sh: intc: Fix use-after-free bug in register_intc_controller()
In the error handling for this function, d is freed without ever
removing it from intc_list which would lead to a use after free.
To fix this, let's only add it to the list after everything has
succeeded.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Fix out of bounds reads when finding clock sources
The current USB-audio driver code doesn't check bLength of each
descriptor at traversing for clock descriptors. That is, when a
device provides a bogus descriptor with a shorter bLength, the driver
might hit out-of-bounds reads.
For addressing it, this patch adds sanity checks to the validator
functions for the clock descriptor traversal. When the descriptor
length is shorter than expected, it's skipped in the loop.
For the clock source and clock multiplier descriptors, we can just
check bLength against the sizeof() of each descriptor type.
OTOH, the clock selector descriptor of UAC2 and UAC3 has an array
of bNrInPins elements and two more fields at its tail, hence those
have to be checked in addition to the sizeof() check.
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix uninitialized value in ocfs2_file_read_iter()
Syzbot has reported the following KMSAN splat:
BUG: KMSAN: uninit-value in ocfs2_file_read_iter+0x9a4/0xf80
ocfs2_file_read_iter+0x9a4/0xf80
__io_read+0x8d4/0x20f0
io_read+0x3e/0xf0
io_issue_sqe+0x42b/0x22c0
io_wq_submit_work+0xaf9/0xdc0
io_worker_handle_work+0xd13/0x2110
io_wq_worker+0x447/0x1410
ret_from_fork+0x6f/0x90
ret_from_fork_asm+0x1a/0x30
Uninit was created at:
__alloc_pages_noprof+0x9a7/0xe00
alloc_pages_mpol_noprof+0x299/0x990
alloc_pages_noprof+0x1bf/0x1e0
allocate_slab+0x33a/0x1250
___slab_alloc+0x12ef/0x35e0
kmem_cache_alloc_bulk_noprof+0x486/0x1330
__io_alloc_req_refill+0x84/0x560
io_submit_sqes+0x172f/0x2f30
__se_sys_io_uring_enter+0x406/0x41c0
__x64_sys_io_uring_enter+0x11f/0x1a0
x64_sys_call+0x2b54/0x3ba0
do_syscall_64+0xcd/0x1e0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Since an instance of 'struct kiocb' may be passed from the block layer
with 'private' field uninitialized, introduce 'ocfs2_iocb_init_rw_locked()'
and use it from where 'ocfs2_dio_end_io()' might take care, i.e. in
'ocfs2_file_read_iter()' and 'ocfs2_file_write_iter()'.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: add range check for conn_rsp_epid in htc_connect_service()
I found the following bug in my fuzzer:
UBSAN: array-index-out-of-bounds in drivers/net/wireless/ath/ath9k/htc_hst.c:26:51
index 255 is out of range for type 'htc_endpoint [22]'
CPU: 0 UID: 0 PID: 8 Comm: kworker/0:0 Not tainted 6.11.0-rc6-dirty #14
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: events request_firmware_work_func
Call Trace:
<TASK>
dump_stack_lvl+0x180/0x1b0
__ubsan_handle_out_of_bounds+0xd4/0x130
htc_issue_send.constprop.0+0x20c/0x230
? _raw_spin_unlock_irqrestore+0x3c/0x70
ath9k_wmi_cmd+0x41d/0x610
? mark_held_locks+0x9f/0xe0
...
Since this bug has been confirmed to be caused by insufficient verification
of conn_rsp_epid, I think it would be appropriate to add a range check for
conn_rsp_epid to htc_connect_service() to prevent the bug from occurring.
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Prevent a potential integer overflow
If the tag length is >= U32_MAX - 3 then the "length + 4" addition
can result in an integer overflow. Address this by splitting the
decoding into several steps so that decode_cb_compound4res() does
not have to perform arithmetic on the unsafe length value.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ipset: add missing range check in bitmap_ip_uadt
When tb[IPSET_ATTR_IP_TO] is not present but tb[IPSET_ATTR_CIDR] exists,
the values of ip and ip_to are slightly swapped. Therefore, the range check
for ip should be done later, but this part is missing and it seems that the
vulnerability occurs.
So we should add missing range checks and remove unnecessary range checks.
In the Linux kernel, the following vulnerability has been resolved:
initramfs: avoid filename buffer overrun
The initramfs filename field is defined in
Documentation/driver-api/early-userspace/buffer-format.rst as:
37 cpio_file := ALGN(4) + cpio_header + filename + "\0" + ALGN(4) + data
...
55 ============= ================== =========================
56 Field name Field size Meaning
57 ============= ================== =========================
...
70 c_namesize 8 bytes Length of filename, including final \0
When extracting an initramfs cpio archive, the kernel's do_name() path
handler assumes a zero-terminated path at @collected, passing it
directly to filp_open() / init_mkdir() / init_mknod().
If a specially crafted cpio entry carries a non-zero-terminated filename
and is followed by uninitialized memory, then a file may be created with
trailing characters that represent the uninitialized memory. The ability
to create an initramfs entry would imply already having full control of
the system, so the buffer overrun shouldn't be considered a security
vulnerability.
Append the output of the following bash script to an existing initramfs
and observe any created /initramfs_test_fname_overrunAA* path. E.g.
./reproducer.sh | gzip >> /myinitramfs
It's easiest to observe non-zero uninitialized memory when the output is
gzipped, as it'll overflow the heap allocated @out_buf in __gunzip(),
rather than the initrd_start+initrd_size block.
---- reproducer.sh ----
nilchar="A" # change to "\0" to properly zero terminate / pad
magic="070701"
ino=1
mode=$(( 0100777 ))
uid=0
gid=0
nlink=1
mtime=1
filesize=0
devmajor=0
devminor=1
rdevmajor=0
rdevminor=0
csum=0
fname="initramfs_test_fname_overrun"
namelen=$(( ${#fname} + 1 )) # plus one to account for terminator
printf "%s%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%s" \
$magic $ino $mode $uid $gid $nlink $mtime $filesize \
$devmajor $devminor $rdevmajor $rdevminor $namelen $csum $fname
termpadlen=$(( 1 + ((4 - ((110 + $namelen) & 3)) % 4) ))
printf "%.s${nilchar}" $(seq 1 $termpadlen)
---- reproducer.sh ----
Symlink filename fields handled in do_symlink() won't overrun past the
data segment, due to the explicit zero-termination of the symlink
target.
Fix filename buffer overrun by aborting the initramfs FSM if any cpio
entry doesn't carry a zero-terminator at the expected (name_len - 1)
offset.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Handle dml allocation failure to avoid crash
[Why]
In the case where a dml allocation fails for any reason, the
current state's dml contexts would no longer be valid. Then
subsequent calls dc_state_copy_internal would shallow copy
invalid memory and if the new state was released, a double
free would occur.
[How]
Reset dml pointers in new_state to NULL and avoid invalid
pointer
(cherry picked from commit bcafdc61529a48f6f06355d78eb41b3aeda5296c)
In the Linux kernel, the following vulnerability has been resolved:
vdpa: solidrun: Fix UB bug with devres
In psnet_open_pf_bar() and snet_open_vf_bar() a string later passed to
pcim_iomap_regions() is placed on the stack. Neither
pcim_iomap_regions() nor the functions it calls copy that string.
Should the string later ever be used, this, consequently, causes
undefined behavior since the stack frame will by then have disappeared.
Fix the bug by allocating the strings on the heap through
devm_kasprintf().