In the Linux kernel, the following vulnerability has been resolved:
nbd: fix race between nbd_alloc_config() and module removal
When nbd module is being removing, nbd_alloc_config() may be
called concurrently by nbd_genl_connect(), although try_module_get()
will return false, but nbd_alloc_config() doesn't handle it.
The race may lead to the leak of nbd_config and its related
resources (e.g, recv_workq) and oops in nbd_read_stat() due
to the unload of nbd module as shown below:
BUG: kernel NULL pointer dereference, address: 0000000000000040
Oops: 0000 [#1] SMP PTI
CPU: 5 PID: 13840 Comm: kworker/u17:33 Not tainted 5.14.0+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Workqueue: knbd16-recv recv_work [nbd]
RIP: 0010:nbd_read_stat.cold+0x130/0x1a4 [nbd]
Call Trace:
recv_work+0x3b/0xb0 [nbd]
process_one_work+0x1ed/0x390
worker_thread+0x4a/0x3d0
kthread+0x12a/0x150
ret_from_fork+0x22/0x30
Fixing it by checking the return value of try_module_get()
in nbd_alloc_config(). As nbd_alloc_config() may return ERR_PTR(-ENODEV),
assign nbd->config only when nbd_alloc_config() succeeds to ensure
the value of nbd->config is binary (valid or NULL).
Also adding a debug message to check the reference counter
of nbd_config during module removal.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Fix races among concurrent prealloc proc writes
We have no protection against concurrent PCM buffer preallocation
changes via proc files, and it may potentially lead to UAF or some
weird problem. This patch applies the PCM open_mutex to the proc
write operation for avoiding the racy proc writes and the PCM stream
open (and further operations).
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Fix races among concurrent hw_params and hw_free calls
Currently we have neither proper check nor protection against the
concurrent calls of PCM hw_params and hw_free ioctls, which may result
in a UAF. Since the existing PCM stream lock can't be used for
protecting the whole ioctl operations, we need a new mutex to protect
those racy calls.
This patch introduced a new mutex, runtime->buffer_mutex, and applies
it to both hw_params and hw_free ioctl code paths. Along with it, the
both functions are slightly modified (the mmap_count check is moved
into the state-check block) for code simplicity.
In the Linux kernel, the following vulnerability has been resolved:
NFSD: prevent integer overflow on 32 bit systems
On a 32 bit system, the "len * sizeof(*p)" operation can have an
integer overflow.
In the Linux kernel, the following vulnerability has been resolved:
NFSD: prevent underflow in nfssvc_decode_writeargs()
Smatch complains:
fs/nfsd/nfsxdr.c:341 nfssvc_decode_writeargs()
warn: no lower bound on 'args->len'
Change the type to unsigned to prevent this issue.
In the Linux kernel, the following vulnerability has been resolved:
ath9k_htc: fix uninit value bugs
Syzbot reported 2 KMSAN bugs in ath9k. All of them are caused by missing
field initialization.
In htc_connect_service() svc_meta_len and pad are not initialized. Based
on code it looks like in current skb there is no service data, so simply
initialize svc_meta_len to 0.
htc_issue_send() does not initialize htc_frame_hdr::control array. Based
on firmware code, it will initialize it by itself, so simply zero whole
array to make KMSAN happy
Fail logs:
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...
Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...
Bytes 4-7 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
usb_submit_urb+0x6c1/0x2aa0 drivers/usb/core/urb.c:430
hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline]
hif_usb_send+0x5f0/0x16f0 drivers/net/wireless/ath/ath9k/hif_usb.c:479
htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline]
htc_connect_service+0x143e/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:275
...
Uninit was created at:
slab_post_alloc_hook mm/slab.h:524 [inline]
slab_alloc_node mm/slub.c:3251 [inline]
__kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0x545/0xf90 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1126 [inline]
htc_connect_service+0x1029/0x1960 drivers/net/wireless/ath/ath9k/htc_hst.c:258
...
Bytes 16-17 of 18 are uninitialized
Memory access of size 18 starts at ffff888027377e00