Linux: >> Linux Kernel >> 3.18.52 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
bpf: support non-r10 register spill/fill to/from stack in precision tracking
Use instruction (jump) history to record instructions that performed
register spill/fill to/from stack, regardless if this was done through
read-only r10 register, or any other register after copying r10 into it
*and* potentially adjusting offset.
To make this work reliably, we push extra per-instruction flags into
instruction history, encoding stack slot index (spi) and stack frame
number in extra 10 bit flags we take away from prev_idx in instruction
history. We don't touch idx field for maximum performance, as it's
checked most frequently during backtracking.
This change removes basically the last remaining practical limitation of
precision backtracking logic in BPF verifier. It fixes known
deficiencies, but also opens up new opportunities to reduce number of
verified states, explored in the subsequent patches.
There are only three differences in selftests' BPF object files
according to veristat, all in the positive direction (less states).
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
-------------------------------------- ------------- --------- --------- ------------- ---------- ---------- -------------
test_cls_redirect_dynptr.bpf.linked3.o cls_redirect 2987 2864 -123 (-4.12%) 240 231 -9 (-3.75%)
xdp_synproxy_kern.bpf.linked3.o syncookie_tc 82848 82661 -187 (-0.23%) 5107 5073 -34 (-0.67%)
xdp_synproxy_kern.bpf.linked3.o syncookie_xdp 85116 84964 -152 (-0.18%) 5162 5130 -32 (-0.62%)
Note, I avoided renaming jmp_history to more generic insn_hist to
minimize number of lines changed and potential merge conflicts between
bpf and bpf-next trees.
Notice also cur_hist_entry pointer reset to NULL at the beginning of
instruction verification loop. This pointer avoids the problem of
relying on last jump history entry's insn_idx to determine whether we
already have entry for current instruction or not. It can happen that we
added jump history entry because current instruction is_jmp_point(), but
also we need to add instruction flags for stack access. In this case, we
don't want to entries, so we need to reuse last added entry, if it is
present.
Relying on insn_idx comparison has the same ambiguity problem as the one
that was fixed recently in [0], so we avoid that.
[0] https://patchwork.kernel.org/project/netdevbpf/patch/20231110002638.4168352-3-andrii@kernel.org/
CVSS Score
5.5
EPSS Score
0.0
Published
2024-11-05
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix user-after-free from session log off
There is racy issue between smb2 session log off and smb2 session setup.
It will cause user-after-free from session log off.
This add session_lock when setting SMB2_SESSION_EXPIRED and referece
count to session struct not to free session while it is being used.
CVSS Score
7.0
EPSS Score
0.0
Published
2024-10-29
In the Linux kernel, the following vulnerability has been resolved:
tty: n_gsm: Fix use-after-free in gsm_cleanup_mux
BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0
drivers/tty/n_gsm.c:3160 [n_gsm]
Read of size 8 at addr ffff88815fe99c00 by task poc/3379
CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56
Hardware name: VMware, Inc. VMware Virtual Platform/440BX
Desktop Reference Platform, BIOS 6.00 11/12/2020
Call Trace:
<TASK>
gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm]
__pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm]
__pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389
update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500
__pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846
__rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161
gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm]
_raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107
__pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm]
ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195
ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79
__pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338
__pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805
tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818
Allocated by task 65:
gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm]
gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm]
gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm]
gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm]
tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391
tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39
flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445
process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229
worker_thread+0x3dc/0x950 kernel/workqueue.c:3391
kthread+0x2a3/0x370 kernel/kthread.c:389
ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257
Freed by task 3367:
kfree+0x126/0x420 mm/slub.c:4580
gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm]
gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm]
tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818
[Analysis]
gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux
can be freed by multi threads through ioctl,which leads
to the occurrence of uaf. Protect it by gsm tx lock.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-29
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.
CVSS Score
7.8
EPSS Score
0.0
Published
2024-10-28
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-22
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-22
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.
CVSS Score
7.0
EPSS Score
0.0
Published
2024-10-21
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.
CVSS Score
7.0
EPSS Score
0.0
Published
2024-10-21
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.
CVSS Score
5.5
EPSS Score
0.0
Published
2024-10-21
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: FIX possible deadlock in rfcomm_sk_state_change
rfcomm_sk_state_change attempts to use sock_lock so it must never be
called with it locked but rfcomm_sock_ioctl always attempt to lock it
causing the following trace:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
------------------------------------------------------
syz-executor386/5093 is trying to acquire lock:
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1671 [inline]
ffff88807c396258 (sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM){+.+.}-{0:0}, at: rfcomm_sk_state_change+0x5b/0x310 net/bluetooth/rfcomm/sock.c:73
but task is already holding lock:
ffff88807badfd28 (&d->lock){+.+.}-{3:3}, at: __rfcomm_dlc_close+0x226/0x6a0 net/bluetooth/rfcomm/core.c:491
CVSS Score
3.3
EPSS Score
0.0
Published
2024-10-21