In the Linux kernel, the following vulnerability has been resolved:
parport: Proper fix for array out-of-bounds access
The recent fix for array out-of-bounds accesses replaced sprintf()
calls blindly with snprintf(). However, since snprintf() returns the
would-be-printed size, not the actually output size, the length
calculation can still go over the given limit.
Use scnprintf() instead of snprintf(), which returns the actually
output letters, for addressing the potential out-of-bounds access
properly.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: Fix multiple init when debugfs is disabled
If bt_debugfs is not created successfully, which happens if either
CONFIG_DEBUG_FS or CONFIG_DEBUG_FS_ALLOW_ALL is unset, then iso_init()
returns early and does not set iso_inited to true. This means that a
subsequent call to iso_init() will result in duplicate calls to
proto_register(), bt_sock_register(), etc.
With CONFIG_LIST_HARDENED and CONFIG_BUG_ON_DATA_CORRUPTION enabled, the
duplicate call to proto_register() triggers this BUG():
list_add double add: new=ffffffffc0b280d0, prev=ffffffffbab56250,
next=ffffffffc0b280d0.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:35!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 2 PID: 887 Comm: bluetoothd Not tainted 6.10.11-1-ao-desktop #1
RIP: 0010:__list_add_valid_or_report+0x9a/0xa0
...
__list_add_valid_or_report+0x9a/0xa0
proto_register+0x2b5/0x340
iso_init+0x23/0x150 [bluetooth]
set_iso_socket_func+0x68/0x1b0 [bluetooth]
kmem_cache_free+0x308/0x330
hci_sock_sendmsg+0x990/0x9e0 [bluetooth]
__sock_sendmsg+0x7b/0x80
sock_write_iter+0x9a/0x110
do_iter_readv_writev+0x11d/0x220
vfs_writev+0x180/0x3e0
do_writev+0xca/0x100
...
This change removes the early return. The check for iso_debugfs being
NULL was unnecessary, it is always NULL when iso_inited is false.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Call iso_exit() on module unload
If iso_init() has been called, iso_exit() must be called on module
unload. Without that, the struct proto that iso_init() registered with
proto_register() becomes invalid, which could cause unpredictable
problems later. In my case, with CONFIG_LIST_HARDENED and
CONFIG_BUG_ON_DATA_CORRUPTION enabled, loading the module again usually
triggers this BUG():
list_add corruption. next->prev should be prev (ffffffffb5355fd0),
but was 0000000000000068. (next=ffffffffc0a010d0).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:29!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 4159 Comm: modprobe Not tainted 6.10.11-4+bt2-ao-desktop #1
RIP: 0010:__list_add_valid_or_report+0x61/0xa0
...
__list_add_valid_or_report+0x61/0xa0
proto_register+0x299/0x320
hci_sock_init+0x16/0xc0 [bluetooth]
bt_init+0x68/0xd0 [bluetooth]
__pfx_bt_init+0x10/0x10 [bluetooth]
do_one_initcall+0x80/0x2f0
do_init_module+0x8b/0x230
__do_sys_init_module+0x15f/0x190
do_syscall_64+0x68/0x110
...
In the Linux kernel, the following vulnerability has been resolved:
uprobe: avoid out-of-bounds memory access of fetching args
Uprobe needs to fetch args into a percpu buffer, and then copy to ring
buffer to avoid non-atomic context problem.
Sometimes user-space strings, arrays can be very large, but the size of
percpu buffer is only page size. And store_trace_args() won't check
whether these data exceeds a single page or not, caused out-of-bounds
memory access.
It could be reproduced by following steps:
1. build kernel with CONFIG_KASAN enabled
2. save follow program as test.c
```
\#include <stdio.h>
\#include <stdlib.h>
\#include <string.h>
// If string length large than MAX_STRING_SIZE, the fetch_store_strlen()
// will return 0, cause __get_data_size() return shorter size, and
// store_trace_args() will not trigger out-of-bounds access.
// So make string length less than 4096.
\#define STRLEN 4093
void generate_string(char *str, int n)
{
int i;
for (i = 0; i < n; ++i)
{
char c = i % 26 + 'a';
str[i] = c;
}
str[n-1] = '\0';
}
void print_string(char *str)
{
printf("%s\n", str);
}
int main()
{
char tmp[STRLEN];
generate_string(tmp, STRLEN);
print_string(tmp);
return 0;
}
```
3. compile program
`gcc -o test test.c`
4. get the offset of `print_string()`
```
objdump -t test | grep -w print_string
0000000000401199 g F .text 000000000000001b print_string
```
5. configure uprobe with offset 0x1199
```
off=0x1199
cd /sys/kernel/debug/tracing/
echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring"
> uprobe_events
echo 1 > events/uprobes/enable
echo 1 > tracing_on
```
6. run `test`, and kasan will report error.
==================================================================
BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0
Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18
Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x55/0x70
print_address_description.constprop.0+0x27/0x310
kasan_report+0x10f/0x120
? strncpy_from_user+0x1d6/0x1f0
strncpy_from_user+0x1d6/0x1f0
? rmqueue.constprop.0+0x70d/0x2ad0
process_fetch_insn+0xb26/0x1470
? __pfx_process_fetch_insn+0x10/0x10
? _raw_spin_lock+0x85/0xe0
? __pfx__raw_spin_lock+0x10/0x10
? __pte_offset_map+0x1f/0x2d0
? unwind_next_frame+0xc5f/0x1f80
? arch_stack_walk+0x68/0xf0
? is_bpf_text_address+0x23/0x30
? kernel_text_address.part.0+0xbb/0xd0
? __kernel_text_address+0x66/0xb0
? unwind_get_return_address+0x5e/0xa0
? __pfx_stack_trace_consume_entry+0x10/0x10
? arch_stack_walk+0xa2/0xf0
? _raw_spin_lock_irqsave+0x8b/0xf0
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? depot_alloc_stack+0x4c/0x1f0
? _raw_spin_unlock_irqrestore+0xe/0x30
? stack_depot_save_flags+0x35d/0x4f0
? kasan_save_stack+0x34/0x50
? kasan_save_stack+0x24/0x50
? mutex_lock+0x91/0xe0
? __pfx_mutex_lock+0x10/0x10
prepare_uprobe_buffer.part.0+0x2cd/0x500
uprobe_dispatcher+0x2c3/0x6a0
? __pfx_uprobe_dispatcher+0x10/0x10
? __kasan_slab_alloc+0x4d/0x90
handler_chain+0xdd/0x3e0
handle_swbp+0x26e/0x3d0
? __pfx_handle_swbp+0x10/0x10
? uprobe_pre_sstep_notifier+0x151/0x1b0
irqentry_exit_to_user_mode+0xe2/0x1b0
asm_exc_int3+0x39/0x40
RIP: 0033:0x401199
Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce
RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206
RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2
RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0
RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20
R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040
R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000
</TASK>
This commit enforces the buffer's maxlen less than a page-size to avoid
store_trace_args() out-of-memory access.
In the Linux kernel, the following vulnerability has been resolved:
media: pci: cx23885: check cx23885_vdev_init() return
cx23885_vdev_init() can return a NULL pointer, but that pointer
is used in the next line without a check.
Add a NULL pointer check and go to the error unwind if it is NULL.
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: fix possible NULL pointer dereference in send_acknowledge()
Handle memory allocation failure from nci_skb_alloc() (calling
alloc_skb()) to avoid possible NULL pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
ntb: ntb_hw_switchtec: Fix use after free vulnerability in switchtec_ntb_remove due to race condition
In the switchtec_ntb_add function, it can call switchtec_ntb_init_sndev
function, then &sndev->check_link_status_work is bound with
check_link_status_work. switchtec_ntb_link_notification may be called
to start the work.
If we remove the module which will call switchtec_ntb_remove to make
cleanup, it will free sndev through kfree(sndev), while the work
mentioned above will be used. The sequence of operations that may lead
to a UAF bug is as follows:
CPU0 CPU1
| check_link_status_work
switchtec_ntb_remove |
kfree(sndev); |
| if (sndev->link_force_down)
| // use sndev
Fix it by ensuring that the work is canceled before proceeding with
the cleanup in switchtec_ntb_remove.
In the Linux kernel, the following vulnerability has been resolved:
io_uring: check if we need to reschedule during overflow flush
In terms of normal application usage, this list will always be empty.
And if an application does overflow a bit, it'll have a few entries.
However, nothing obviously prevents syzbot from running a test case
that generates a ton of overflow entries, and then flushing them can
take quite a while.
Check for needing to reschedule while flushing, and drop our locks and
do so if necessary. There's no state to maintain here as overflows
always prune from head-of-list, hence it's fine to drop and reacquire
the locks at the end of the loop.
In the Linux kernel, the following vulnerability has been resolved:
i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition
In the cdns_i3c_master_probe function, &master->hj_work is bound with
cdns_i3c_master_hj. And cdns_i3c_master_interrupt can call
cnds_i3c_master_demux_ibis function to start the work.
If we remove the module which will call cdns_i3c_master_remove to
make cleanup, it will free master->base through i3c_master_unregister
while the work mentioned above will be used. The sequence of operations
that may lead to a UAF bug is as follows:
CPU0 CPU1
| cdns_i3c_master_hj
cdns_i3c_master_remove |
i3c_master_unregister(&master->base) |
device_unregister(&master->dev) |
device_release |
//free master->base |
| i3c_master_do_daa(&master->base)
| //use master->base
Fix it by ensuring that the work is canceled before proceeding with
the cleanup in cdns_i3c_master_remove.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rtrs-srv: Avoid null pointer deref during path establishment
For RTRS path establishment, RTRS client initiates and completes con_num
of connections. After establishing all its connections, the information
is exchanged between the client and server through the info_req message.
During this exchange, it is essential that all connections have been
established, and the state of the RTRS srv path is CONNECTED.
So add these sanity checks, to make sure we detect and abort process in
error scenarios to avoid null pointer deref.