In the Linux kernel, the following vulnerability has been resolved:
bpf: avoid holding freeze_mutex during mmap operation
We use map->freeze_mutex to prevent races between map_freeze() and
memory mapping BPF map contents with writable permissions. The way we
naively do this means we'll hold freeze_mutex for entire duration of all
the mm and VMA manipulations, which is completely unnecessary. This can
potentially also lead to deadlocks, as reported by syzbot in [0].
So, instead, hold freeze_mutex only during writeability checks, bump
(proactively) "write active" count for the map, unlock the mutex and
proceed with mmap logic. And only if something went wrong during mmap
logic, then undo that "write active" counter increment.
[0] https://lore.kernel.org/bpf/678dcbc9.050a0220.303755.0066.GAE@google.com/
In the Linux kernel, the following vulnerability has been resolved:
ibmvnic: Don't reference skb after sending to VIOS
Previously, after successfully flushing the xmit buffer to VIOS,
the tx_bytes stat was incremented by the length of the skb.
It is invalid to access the skb memory after sending the buffer to
the VIOS because, at any point after sending, the VIOS can trigger
an interrupt to free this memory. A race between reading skb->len
and freeing the skb is possible (especially during LPM) and will
result in use-after-free:
==================================================================
BUG: KASAN: slab-use-after-free in ibmvnic_xmit+0x75c/0x1808 [ibmvnic]
Read of size 4 at addr c00000024eb48a70 by task hxecom/14495
<...>
Call Trace:
[c000000118f66cf0] [c0000000018cba6c] dump_stack_lvl+0x84/0xe8 (unreliable)
[c000000118f66d20] [c0000000006f0080] print_report+0x1a8/0x7f0
[c000000118f66df0] [c0000000006f08f0] kasan_report+0x128/0x1f8
[c000000118f66f00] [c0000000006f2868] __asan_load4+0xac/0xe0
[c000000118f66f20] [c0080000046eac84] ibmvnic_xmit+0x75c/0x1808 [ibmvnic]
[c000000118f67340] [c0000000014be168] dev_hard_start_xmit+0x150/0x358
<...>
Freed by task 0:
kasan_save_stack+0x34/0x68
kasan_save_track+0x2c/0x50
kasan_save_free_info+0x64/0x108
__kasan_mempool_poison_object+0x148/0x2d4
napi_skb_cache_put+0x5c/0x194
net_tx_action+0x154/0x5b8
handle_softirqs+0x20c/0x60c
do_softirq_own_stack+0x6c/0x88
<...>
The buggy address belongs to the object at c00000024eb48a00 which
belongs to the cache skbuff_head_cache of size 224
==================================================================
In the Linux kernel, the following vulnerability has been resolved:
geneve: Fix use-after-free in geneve_find_dev().
syzkaller reported a use-after-free in geneve_find_dev() [0]
without repro.
geneve_configure() links struct geneve_dev.next to
net_generic(net, geneve_net_id)->geneve_list.
The net here could differ from dev_net(dev) if IFLA_NET_NS_PID,
IFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set.
When dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally
calls unregister_netdevice_queue() for each dev in the netns,
and later the dev is freed.
However, its geneve_dev.next is still linked to the backend UDP
socket netns.
Then, use-after-free will occur when another geneve dev is created
in the netns.
Let's call geneve_dellink() instead in geneve_destroy_tunnels().
[0]:
BUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline]
BUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
Read of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441
CPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d
Hardware name: linux,dummy-virt (DT)
Call trace:
show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x16c/0x6f0 mm/kasan/report.c:489
kasan_report+0xc0/0x120 mm/kasan/report.c:602
__asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379
geneve_find_dev drivers/net/geneve.c:1295 [inline]
geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634
rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795
__rtnl_newlink net/core/rtnetlink.c:3906 [inline]
rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:713 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x410/0x6f8 net/socket.c:2568
___sys_sendmsg+0x178/0x1d8 net/socket.c:2622
__sys_sendmsg net/socket.c:2654 [inline]
__do_sys_sendmsg net/socket.c:2659 [inline]
__se_sys_sendmsg net/socket.c:2657 [inline]
__arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132
do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151
el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600
Allocated by task 13247:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x30/0x68 mm/kasan/common.c:68
kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4298 [inline]
__kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304
__kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645
alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470
rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604
rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780
__rtnl_newlink net/core/rtnetlink.c:3906 [inline]
rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
netlink_unicast_kernel net/netlink/af_n
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: f_midi: f_midi_complete to call queue_work
When using USB MIDI, a lock is attempted to be acquired twice through a
re-entrant call to f_midi_transmit, causing a deadlock.
Fix it by using queue_work() to schedule the inner f_midi_transmit() via
a high priority work queue from the completion handler.
In the Linux kernel, the following vulnerability has been resolved:
nfp: bpf: Add check for nfp_app_ctrl_msg_alloc()
Add check for the return value of nfp_app_ctrl_msg_alloc() in
nfp_bpf_cmsg_alloc() to prevent null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: Add check for next_buffer in receive_encrypted_standard()
Add check for the return value of cifs_buf_get() and cifs_small_buf_get()
in receive_encrypted_standard() to prevent null pointer dereference.
In the Linux kernel, the following vulnerability has been resolved:
acct: perform last write from workqueue
In [1] it was reported that the acct(2) system call can be used to
trigger NULL deref in cases where it is set to write to a file that
triggers an internal lookup. This can e.g., happen when pointing acc(2)
to /sys/power/resume. At the point the where the write to this file
happens the calling task has already exited and called exit_fs(). A
lookup will thus trigger a NULL-deref when accessing current->fs.
Reorganize the code so that the the final write happens from the
workqueue but with the caller's credentials. This preserves the
(strange) permission model and has almost no regression risk.
This api should stop to exist though.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix racy issue from session lookup and expire
Increment the session reference count within the lock for lookup to avoid
racy issue with session expire.
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_midi: fix MIDI Streaming descriptor lengths
While the MIDI jacks are configured correctly, and the MIDIStreaming
endpoint descriptors are filled with the correct information,
bNumEmbMIDIJack and bLength are set incorrectly in these descriptors.
This does not matter when the numbers of in and out ports are equal, but
when they differ the host will receive broken descriptors with
uninitialized stack memory leaking into the descriptor for whichever
value is smaller.
The precise meaning of "in" and "out" in the port counts is not clearly
defined and can be confusing. But elsewhere the driver consistently
uses this to match the USB meaning of IN and OUT viewed from the host,
so that "in" ports send data to the host and "out" ports receive data
from it.