In the Linux kernel, the following vulnerability has been resolved:
netrom: check buffer length before accessing it
Syzkaller reports an uninit value read from ax25cmp when sending raw message
through ieee802154 implementation.
=====================================================
BUG: KMSAN: uninit-value in ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119
ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119
nr_dev_get+0x20e/0x450 net/netrom/nr_route.c:601
nr_route_frame+0x1a2/0xfc0 net/netrom/nr_route.c:774
nr_xmit+0x5a/0x1c0 net/netrom/nr_dev.c:144
__netdev_start_xmit include/linux/netdevice.h:4940 [inline]
netdev_start_xmit include/linux/netdevice.h:4954 [inline]
xmit_one net/core/dev.c:3548 [inline]
dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564
__dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349
dev_queue_xmit include/linux/netdevice.h:3134 [inline]
raw_sendmsg+0x654/0xc10 net/ieee802154/socket.c:299
ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
__sys_sendmsg net/socket.c:2667 [inline]
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Uninit was created at:
slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
__alloc_skb+0x318/0x740 net/core/skbuff.c:651
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334
sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2780
sock_alloc_send_skb include/net/sock.h:1884 [inline]
raw_sendmsg+0x36d/0xc10 net/ieee802154/socket.c:282
ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638
__sys_sendmsg net/socket.c:2667 [inline]
__do_sys_sendmsg net/socket.c:2676 [inline]
__se_sys_sendmsg net/socket.c:2674 [inline]
__x64_sys_sendmsg+0x307/0x490 net/socket.c:2674
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
CPU: 0 PID: 5037 Comm: syz-executor166 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
=====================================================
This issue occurs because the skb buffer is too small, and it's actual
allocation is aligned. This hides an actual issue, which is that nr_route_frame
does not validate the buffer size before using it.
Fix this issue by checking skb->len before accessing any fields in skb->data.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
jffs2: Prevent rtime decompress memory corruption
The rtime decompression routine does not fully check bounds during the
entirety of the decompression pass and can corrupt memory outside the
decompression buffer if the compressed data is corrupted. This adds the
required check to prevent this failure mode.
In the Linux kernel, the following vulnerability has been resolved:
scsi: megaraid_sas: Fix for a potential deadlock
This fixes a 'possible circular locking dependency detected' warning
CPU0 CPU1
---- ----
lock(&instance->reset_mutex);
lock(&shost->scan_mutex);
lock(&instance->reset_mutex);
lock(&shost->scan_mutex);
Fix this by temporarily releasing the reset_mutex.
In the Linux kernel, the following vulnerability has been resolved:
drm/dp_mst: Ensure mst_primary pointer is valid in drm_dp_mst_handle_up_req()
While receiving an MST up request message from one thread in
drm_dp_mst_handle_up_req(), the MST topology could be removed from
another thread via drm_dp_mst_topology_mgr_set_mst(false), freeing
mst_primary and setting drm_dp_mst_topology_mgr::mst_primary to NULL.
This could lead to a NULL deref/use-after-free of mst_primary in
drm_dp_mst_handle_up_req().
Avoid the above by holding a reference for mst_primary in
drm_dp_mst_handle_up_req() while it's used.
v2: Fix kfreeing the request if getting an mst_primary reference fails.
In the Linux kernel, the following vulnerability has been resolved:
drm/modes: Avoid divide by zero harder in drm_mode_vrefresh()
drm_mode_vrefresh() is trying to avoid divide by zero
by checking whether htotal or vtotal are zero. But we may
still end up with a div-by-zero of vtotal*htotal*...
In the Linux kernel, the following vulnerability has been resolved:
netfilter: IDLETIMER: Fix for possible ABBA deadlock
Deletion of the last rule referencing a given idletimer may happen at
the same time as a read of its file in sysfs:
| ======================================================
| WARNING: possible circular locking dependency detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| ------------------------------------------------------
| iptables/3303 is trying to acquire lock:
| ffff8881057e04b8 (kn->active#48){++++}-{0:0}, at: __kernfs_remove+0x20
|
| but task is already holding lock:
| ffffffffa0249068 (list_mutex){+.+.}-{3:3}, at: idletimer_tg_destroy_v]
|
| which lock already depends on the new lock.
A simple reproducer is:
| #!/bin/bash
|
| while true; do
| iptables -A INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| iptables -D INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| done &
| while true; do
| cat /sys/class/xt_idletimer/timers/testme >/dev/null
| done
Avoid this by freeing list_mutex right after deleting the element from
the list, then continuing with the teardown.
In the Linux kernel, the following vulnerability has been resolved:
dma-debug: fix a possible deadlock on radix_lock
radix_lock() shouldn't be held while holding dma_hash_entry[idx].lock
otherwise, there's a possible deadlock scenario when
dma debug API is called holding rq_lock():
CPU0 CPU1 CPU2
dma_free_attrs()
check_unmap() add_dma_entry() __schedule() //out
(A) rq_lock()
get_hash_bucket()
(A) dma_entry_hash
check_sync()
(A) radix_lock() (W) dma_entry_hash
dma_entry_free()
(W) radix_lock()
// CPU2's one
(W) rq_lock()
CPU1 situation can happen when it extending radix tree and
it tries to wake up kswapd via wake_all_kswapd().
CPU2 situation can happen while perf_event_task_sched_out()
(i.e. dma sync operation is called while deleting perf_event using
etm and etr tmc which are Arm Coresight hwtracing driver backends).
To remove this possible situation, call dma_entry_free() after
put_hash_bucket() in check_unmap().
In the Linux kernel, the following vulnerability has been resolved:
dlm: fix possible lkb_resource null dereference
This patch fixes a possible null pointer dereference when this function is
called from request_lock() as lkb->lkb_resource is not assigned yet,
only after validate_lock_args() by calling attach_lkb(). Another issue
is that a resource name could be a non printable bytearray and we cannot
assume to be ASCII coded.
The log functionality is probably never being hit when DLM is used in
normal way and no debug logging is enabled. The null pointer dereference
can only occur on a new created lkb that does not have the resource
assigned yet, it probably never hits the null pointer dereference but we
should be sure that other changes might not change this behaviour and we
actually can hit the mentioned null pointer dereference.
In this patch we just drop the printout of the resource name, the lkb id
is enough to make a possible connection to a resource name if this
exists.
In the Linux kernel, the following vulnerability has been resolved:
pinmux: Use sequential access to access desc->pinmux data
When two client of the same gpio call pinctrl_select_state() for the
same functionality, we are seeing NULL pointer issue while accessing
desc->mux_owner.
Let's say two processes A, B executing in pin_request() for the same pin
and process A updates the desc->mux_usecount but not yet updated the
desc->mux_owner while process B see the desc->mux_usecount which got
updated by A path and further executes strcmp and while accessing
desc->mux_owner it crashes with NULL pointer.
Serialize the access to mux related setting with a mutex lock.
cpu0 (process A) cpu1(process B)
pinctrl_select_state() { pinctrl_select_state() {
pin_request() { pin_request() {
...
....
} else {
desc->mux_usecount++;
desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
if (desc->mux_usecount > 1)
return 0;
desc->mux_owner = owner;
} }