| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iommu/sprd: Release dma buffer to avoid memory leak
When attaching to a domain, the driver would alloc a DMA buffer which
is used to store address mapping table, and it need to be released
when the IOMMU domain is freed. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: htc_hst: free skb in ath9k_htc_rx_msg() if there is no callback function
It is stated that ath9k_htc_rx_msg() either frees the provided skb or
passes its management to another callback function. However, the skb is
not freed in case there is no another callback function, and Syzkaller was
able to cause a memory leak. Also minor comment fix.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix dropping valid root bus resources with .end = zero
On r8a7791/koelsch:
kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xc3a34e00 (size 64):
comm "swapper/0", pid 1, jiffies 4294937460 (age 199.080s)
hex dump (first 32 bytes):
b4 5d 81 f0 b4 5d 81 f0 c0 b0 a2 c3 00 00 00 00 .]...]..........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<fe3aa979>] __kmalloc+0xf0/0x140
[<34bd6bc0>] resource_list_create_entry+0x18/0x38
[<767046bc>] pci_add_resource_offset+0x20/0x68
[<b3f3edf2>] devm_of_pci_get_host_bridge_resources.constprop.0+0xb0/0x390
When coalescing two resources for a contiguous aperture, the second
resource is enlarged to cover the full contiguous range, while the first
resource is marked invalid. This invalidation is done by clearing the
flags, start, and end members.
When adding the initial resources to the bus later, invalid resources are
skipped. Unfortunately, the check for an invalid resource considers only
the end member, causing false positives.
E.g. on r8a7791/koelsch, root bus resource 0 ("bus 00") is skipped, and no
longer registered with pci_bus_insert_busn_res() (causing the memory leak),
nor printed:
pci-rcar-gen2 ee090000.pci: host bridge /soc/pci@ee090000 ranges:
pci-rcar-gen2 ee090000.pci: MEM 0x00ee080000..0x00ee08ffff -> 0x00ee080000
pci-rcar-gen2 ee090000.pci: PCI: revision 11
pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00
-pci_bus 0000:00: root bus resource [bus 00]
pci_bus 0000:00: root bus resource [mem 0xee080000-0xee08ffff]
Fix this by only skipping resources where all of the flags, start, and end
members are zero. |
| In the Linux kernel, the following vulnerability has been resolved:
dm clone: Fix UAF in clone_dtr()
Dm_clone also has the same UAF problem when dm_resume()
and dm_destroy() are concurrent.
Therefore, cancelling timer again in clone_dtr(). |
| In the Linux kernel, the following vulnerability has been resolved:
posix-timers: Prevent RT livelock in itimer_delete()
itimer_delete() has a retry loop when the timer is concurrently expired. On
non-RT kernels this just spin-waits until the timer callback has completed,
except for posix CPU timers which have HAVE_POSIX_CPU_TIMERS_TASK_WORK
enabled.
In that case and on RT kernels the existing task could live lock when
preempting the task which does the timer delivery.
Replace spin_unlock() with an invocation of timer_wait_running() to handle
it the same way as the other retry loops in the posix timer code. |
| In the Linux kernel, the following vulnerability has been resolved:
ARM: zynq: Fix refcount leak in zynq_early_slcr_init
of_find_compatible_node() returns a node pointer with refcount incremented,
we should use of_node_put() on error path.
Add missing of_node_put() to avoid refcount leak. |
| In the Linux kernel, the following vulnerability has been resolved:
kcm: Fix error handling for SOCK_DGRAM in kcm_sendmsg().
syzkaller found a memory leak in kcm_sendmsg(), and commit c821a88bd720
("kcm: Fix memory leak in error path of kcm_sendmsg()") suppressed it by
updating kcm_tx_msg(head)->last_skb if partial data is copied so that the
following sendmsg() will resume from the skb.
However, we cannot know how many bytes were copied when we get the error.
Thus, we could mess up the MSG_MORE queue.
When kcm_sendmsg() fails for SOCK_DGRAM, we should purge the queue as we
do so for UDP by udp_flush_pending_frames().
Even without this change, when the error occurred, the following sendmsg()
resumed from a wrong skb and the queue was messed up. However, we have
yet to get such a report, and only syzkaller stumbled on it. So, this
can be changed safely.
Note this does not change SOCK_SEQPACKET behaviour. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: via-sdmmc: fix return value check of mmc_add_host()
mmc_add_host() may return error, if we ignore its return value,
it will lead two issues:
1. The memory that allocated in mmc_alloc_host() is leaked.
2. In the remove() path, mmc_remove_host() will be called to
delete device, but it's not added yet, it will lead a kernel
crash because of null-ptr-deref in device_del().
Fix this by checking the return value and goto error path which
will call mmc_free_host(). |
| In the Linux kernel, the following vulnerability has been resolved:
ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()
Wear-leveling entry could be freed in error path, which may be accessed
again in eraseblk_count_seq_show(), for example:
__erase_worker eraseblk_count_seq_show
wl = ubi->lookuptbl[*block_number]
if (wl)
wl_entry_destroy
ubi->lookuptbl[e->pnum] = NULL
kmem_cache_free(ubi_wl_entry_slab, e)
erase_count = wl->ec // UAF!
Wear-leveling entry updating/accessing in ubi->lookuptbl should be
protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize
wl entry accessing between wl_entry_destroy() and
eraseblk_count_seq_show().
Fetch a reproducer in [Link]. |
| In the Linux kernel, the following vulnerability has been resolved:
md/raid0, raid10: Don't set discard sectors for request queue
It should use disk_stack_limits to get a proper max_discard_sectors
rather than setting a value by stack drivers.
And there is a bug. If all member disks are rotational devices,
raid0/raid10 set max_discard_sectors. So the member devices are
not ssd/nvme, but raid0/raid10 export the wrong value. It reports
warning messages in function __blkdev_issue_discard when mkfs.xfs
like this:
[ 4616.022599] ------------[ cut here ]------------
[ 4616.027779] WARNING: CPU: 4 PID: 99634 at block/blk-lib.c:50 __blkdev_issue_discard+0x16a/0x1a0
[ 4616.140663] RIP: 0010:__blkdev_issue_discard+0x16a/0x1a0
[ 4616.146601] Code: 24 4c 89 20 31 c0 e9 fe fe ff ff c1 e8 09 8d 48 ff 4c 89 f0 4c 09 e8 48 85 c1 0f 84 55 ff ff ff b8 ea ff ff ff e9 df fe ff ff <0f> 0b 48 8d 74 24 08 e8 ea d6 00 00 48 c7 c6 20 1e 89 ab 48 c7 c7
[ 4616.167567] RSP: 0018:ffffaab88cbffca8 EFLAGS: 00010246
[ 4616.173406] RAX: ffff9ba1f9e44678 RBX: 0000000000000000 RCX: ffff9ba1c9792080
[ 4616.181376] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9ba1c9792080
[ 4616.189345] RBP: 0000000000000cc0 R08: ffffaab88cbffd10 R09: 0000000000000000
[ 4616.197317] R10: 0000000000000012 R11: 0000000000000000 R12: 0000000000000000
[ 4616.205288] R13: 0000000000400000 R14: 0000000000000cc0 R15: ffff9ba1c9792080
[ 4616.213259] FS: 00007f9a5534e980(0000) GS:ffff9ba1b7c80000(0000) knlGS:0000000000000000
[ 4616.222298] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4616.228719] CR2: 000055a390a4c518 CR3: 0000000123e40006 CR4: 00000000001706e0
[ 4616.236689] Call Trace:
[ 4616.239428] blkdev_issue_discard+0x52/0xb0
[ 4616.244108] blkdev_common_ioctl+0x43c/0xa00
[ 4616.248883] blkdev_ioctl+0x116/0x280
[ 4616.252977] __x64_sys_ioctl+0x8a/0xc0
[ 4616.257163] do_syscall_64+0x5c/0x90
[ 4616.261164] ? handle_mm_fault+0xc5/0x2a0
[ 4616.265652] ? do_user_addr_fault+0x1d8/0x690
[ 4616.270527] ? do_syscall_64+0x69/0x90
[ 4616.274717] ? exc_page_fault+0x62/0x150
[ 4616.279097] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 4616.284748] RIP: 0033:0x7f9a55398c6b |
| In the Linux kernel, the following vulnerability has been resolved:
pstore: Avoid kcore oops by vmap()ing with VM_IOREMAP
An oops can be induced by running 'cat /proc/kcore > /dev/null' on
devices using pstore with the ram backend because kmap_atomic() assumes
lowmem pages are accessible with __va().
Unable to handle kernel paging request at virtual address ffffff807ff2b000
Mem abort info:
ESR = 0x96000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000081d87000
[ffffff807ff2b000] pgd=180000017fe18003, p4d=180000017fe18003, pud=180000017fe18003, pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in: dm_integrity
CPU: 7 PID: 21179 Comm: perf Not tainted 5.15.67-10882-ge4eb2eb988cd #1 baa443fb8e8477896a370b31a821eb2009f9bfba
Hardware name: Google Lazor (rev3 - 8) (DT)
pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __memcpy+0x110/0x260
lr : vread+0x194/0x294
sp : ffffffc013ee39d0
x29: ffffffc013ee39f0 x28: 0000000000001000 x27: ffffff807ff2b000
x26: 0000000000001000 x25: ffffffc0085a2000 x24: ffffff802d4b3000
x23: ffffff80f8a60000 x22: ffffff802d4b3000 x21: ffffffc0085a2000
x20: ffffff8080b7bc68 x19: 0000000000001000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffffffd3073f2e60
x14: ffffffffad588000 x13: 0000000000000000 x12: 0000000000000001
x11: 00000000000001a2 x10: 00680000fff2bf0b x9 : 03fffffff807ff2b
x8 : 0000000000000001 x7 : 0000000000000000 x6 : 0000000000000000
x5 : ffffff802d4b4000 x4 : ffffff807ff2c000 x3 : ffffffc013ee3a78
x2 : 0000000000001000 x1 : ffffff807ff2b000 x0 : ffffff802d4b3000
Call trace:
__memcpy+0x110/0x260
read_kcore+0x584/0x778
proc_reg_read+0xb4/0xe4
During early boot, memblock reserves the pages for the ramoops reserved
memory node in DT that would otherwise be part of the direct lowmem
mapping. Pstore's ram backend reuses those reserved pages to change the
memory type (writeback or non-cached) by passing the pages to vmap()
(see pfn_to_page() usage in persistent_ram_vmap() for more details) with
specific flags. When read_kcore() starts iterating over the vmalloc
region, it runs over the virtual address that vmap() returned for
ramoops. In aligned_vread() the virtual address is passed to
vmalloc_to_page() which returns the page struct for the reserved lowmem
area. That lowmem page is passed to kmap_atomic(), which effectively
calls page_to_virt() that assumes a lowmem page struct must be directly
accessible with __va() and friends. These pages are mapped via vmap()
though, and the lowmem mapping was never made, so accessing them via the
lowmem virtual address oopses like above.
Let's side-step this problem by passing VM_IOREMAP to vmap(). This will
tell vread() to not include the ramoops region in the kcore. Instead the
area will look like a bunch of zeros. The alternative is to teach kmap()
about vmalloc areas that intersect with lowmem. Presumably such a change
isn't a one-liner, and there isn't much interest in inspecting the
ramoops region in kcore files anyway, so the most expedient route is
taken for now. |
| In the Linux kernel, the following vulnerability has been resolved:
regulator: core: Use different devices for resource allocation and DT lookup
Following by the below discussion, there's the potential UAF issue
between regulator and mfd.
https://lore.kernel.org/all/20221128143601.1698148-1-yangyingliang@huawei.com/
From the analysis of Yingliang
CPU A |CPU B
mt6370_probe() |
devm_mfd_add_devices() |
|mt6370_regulator_probe()
| regulator_register()
| //allocate init_data and add it to devres
| regulator_of_get_init_data()
i2c_unregister_device() |
device_del() |
devres_release_all() |
// init_data is freed |
release_nodes() |
| // using init_data causes UAF
| regulator_register()
It's common to use mfd core to create child device for the regulator.
In order to do the DT lookup for init data, the child that registered
the regulator would pass its parent as the parameter. And this causes
init data resource allocated to its parent, not itself. The issue happen
when parent device is going to release and regulator core is still doing
some operation of init data constraint for the regulator of child device.
To fix it, this patch expand 'regulator_register' API to use the
different devices for init data allocation and DT lookup. |
| In the Linux kernel, the following vulnerability has been resolved:
RISC-V: Make port I/O string accessors actually work
Fix port I/O string accessors such as `insb', `outsb', etc. which use
the physical PCI port I/O address rather than the corresponding memory
mapping to get at the requested location, which in turn breaks at least
accesses made by our parport driver to a PCIe parallel port such as:
PCI parallel port detected: 1415:c118, I/O at 0x1000(0x1008), IRQ 20
parport0: PC-style at 0x1000 (0x1008), irq 20, using FIFO [PCSPP,TRISTATE,COMPAT,EPP,ECP]
causing a memory access fault:
Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000001008
Oops [#1]
Modules linked in:
CPU: 1 PID: 350 Comm: cat Not tainted 6.0.0-rc2-00283-g10d4879f9ef0-dirty #23
Hardware name: SiFive HiFive Unmatched A00 (DT)
epc : parport_pc_fifo_write_block_pio+0x266/0x416
ra : parport_pc_fifo_write_block_pio+0xb4/0x416
epc : ffffffff80542c3e ra : ffffffff80542a8c sp : ffffffd88899fc60
gp : ffffffff80fa2700 tp : ffffffd882b1e900 t0 : ffffffd883d0b000
t1 : ffffffffff000002 t2 : 4646393043330a38 s0 : ffffffd88899fcf0
s1 : 0000000000001000 a0 : 0000000000000010 a1 : 0000000000000000
a2 : ffffffd883d0a010 a3 : 0000000000000023 a4 : 00000000ffff8fbb
a5 : ffffffd883d0a001 a6 : 0000000100000000 a7 : ffffffc800000000
s2 : ffffffffff000002 s3 : ffffffff80d28880 s4 : ffffffff80fa1f50
s5 : 0000000000001008 s6 : 0000000000000008 s7 : ffffffd883d0a000
s8 : 0004000000000000 s9 : ffffffff80dc1d80 s10: ffffffd8807e4000
s11: 0000000000000000 t3 : 00000000000000ff t4 : 393044410a303930
t5 : 0000000000001000 t6 : 0000000000040000
status: 0000000200000120 badaddr: 0000000000001008 cause: 000000000000000f
[<ffffffff80543212>] parport_pc_compat_write_block_pio+0xfe/0x200
[<ffffffff8053bbc0>] parport_write+0x46/0xf8
[<ffffffff8050530e>] lp_write+0x158/0x2d2
[<ffffffff80185716>] vfs_write+0x8e/0x2c2
[<ffffffff80185a74>] ksys_write+0x52/0xc2
[<ffffffff80185af2>] sys_write+0xe/0x16
[<ffffffff80003770>] ret_from_syscall+0x0/0x2
---[ end trace 0000000000000000 ]---
For simplicity address the problem by adding PCI_IOBASE to the physical
address requested in the respective wrapper macros only, observing that
the raw accessors such as `__insb', `__outsb', etc. are not supposed to
be used other than by said macros. Remove the cast to `long' that is no
longer needed on `addr' now that it is used as an offset from PCI_IOBASE
and add parentheses around `addr' needed for predictable evaluation in
macro expansion. No need to make said adjustments in separate changes
given that current code is gravely broken and does not ever work. |
| In the Linux kernel, the following vulnerability has been resolved:
vhost_vdpa: fix the crash in unmap a large memory
While testing in vIOMMU, sometimes Guest will unmap very large memory,
which will cause the crash. To fix this, add a new function
vhost_vdpa_general_unmap(). This function will only unmap the memory
that saved in iotlb.
Call Trace:
[ 647.820144] ------------[ cut here ]------------
[ 647.820848] kernel BUG at drivers/iommu/intel/iommu.c:1174!
[ 647.821486] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[ 647.822082] CPU: 10 PID: 1181 Comm: qemu-system-x86 Not tainted 6.0.0-rc1home_lulu_2452_lulu7_vhost+ #62
[ 647.823139] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qem4
[ 647.824365] RIP: 0010:domain_unmap+0x48/0x110
[ 647.825424] Code: 48 89 fb 8d 4c f6 1e 39 c1 0f 4f c8 83 e9 0c 83 f9 3f 7f 18 48 89 e8 48 d3 e8 48 85 c0 75 59
[ 647.828064] RSP: 0018:ffffae5340c0bbf0 EFLAGS: 00010202
[ 647.828973] RAX: 0000000000000001 RBX: ffff921793d10540 RCX: 000000000000001b
[ 647.830083] RDX: 00000000080000ff RSI: 0000000000000001 RDI: ffff921793d10540
[ 647.831214] RBP: 0000000007fc0100 R08: ffffae5340c0bcd0 R09: 0000000000000003
[ 647.832388] R10: 0000007fc0100000 R11: 0000000000100000 R12: 00000000080000ff
[ 647.833668] R13: ffffae5340c0bcd0 R14: ffff921793d10590 R15: 0000008000100000
[ 647.834782] FS: 00007f772ec90640(0000) GS:ffff921ce7a80000(0000) knlGS:0000000000000000
[ 647.836004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 647.836990] CR2: 00007f02c27a3a20 CR3: 0000000101b0c006 CR4: 0000000000372ee0
[ 647.838107] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 647.839283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 647.840666] Call Trace:
[ 647.841437] <TASK>
[ 647.842107] intel_iommu_unmap_pages+0x93/0x140
[ 647.843112] __iommu_unmap+0x91/0x1b0
[ 647.844003] iommu_unmap+0x6a/0x95
[ 647.844885] vhost_vdpa_unmap+0x1de/0x1f0 [vhost_vdpa]
[ 647.845985] vhost_vdpa_process_iotlb_msg+0xf0/0x90b [vhost_vdpa]
[ 647.847235] ? _raw_spin_unlock+0x15/0x30
[ 647.848181] ? _copy_from_iter+0x8c/0x580
[ 647.849137] vhost_chr_write_iter+0xb3/0x430 [vhost]
[ 647.850126] vfs_write+0x1e4/0x3a0
[ 647.850897] ksys_write+0x53/0xd0
[ 647.851688] do_syscall_64+0x3a/0x90
[ 647.852508] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 647.853457] RIP: 0033:0x7f7734ef9f4f
[ 647.854408] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 76 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c8
[ 647.857217] RSP: 002b:00007f772ec8f040 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[ 647.858486] RAX: ffffffffffffffda RBX: 00000000fef00000 RCX: 00007f7734ef9f4f
[ 647.859713] RDX: 0000000000000048 RSI: 00007f772ec8f090 RDI: 0000000000000010
[ 647.860942] RBP: 00007f772ec8f1a0 R08: 0000000000000000 R09: 0000000000000000
[ 647.862206] R10: 0000000000000001 R11: 0000000000000293 R12: 0000000000000010
[ 647.863446] R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff01100000
[ 647.864692] </TASK>
[ 647.865458] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs v]
[ 647.874688] ---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix infinite loop in nilfs_mdt_get_block()
If the disk image that nilfs2 mounts is corrupted and a virtual block
address obtained by block lookup for a metadata file is invalid,
nilfs_bmap_lookup_at_level() may return the same internal return code as
-ENOENT, meaning the block does not exist in the metadata file.
This duplication of return codes confuses nilfs_mdt_get_block(), causing
it to read and create a metadata block indefinitely.
In particular, if this happens to the inode metadata file, ifile,
semaphore i_rwsem can be left held, causing task hangs in lock_mount.
Fix this issue by making nilfs_bmap_lookup_at_level() treat virtual block
address translation failures with -ENOENT as metadata corruption instead
of returning the error code. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7921: fix use after free in mt7921_acpi_read()
Don't dereference "sar_root" after it has been freed. |
| In the Linux kernel, the following vulnerability has been resolved:
NFSv4: Fix a credential leak in _nfs4_discover_trunking() |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix xid leak in cifs_ses_add_channel()
Before return, should free the xid, otherwise, the
xid will be leaked. |
| In the Linux kernel, the following vulnerability has been resolved:
rapidio: rio: fix possible name leak in rio_register_mport()
If device_register() returns error, the name allocated by dev_set_name()
need be freed. It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and
list_del() is called to delete the port from rio_mports. |
| In the Linux kernel, the following vulnerability has been resolved:
usb-storage: alauda: Fix uninit-value in alauda_check_media()
Syzbot got KMSAN to complain about access to an uninitialized value in
the alauda subdriver of usb-storage:
BUG: KMSAN: uninit-value in alauda_transport+0x462/0x57f0
drivers/usb/storage/alauda.c:1137
CPU: 0 PID: 12279 Comm: usb-storage Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
__msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
alauda_check_media+0x344/0x3310 drivers/usb/storage/alauda.c:460
The problem is that alauda_check_media() doesn't verify that its USB
transfer succeeded before trying to use the received data. What
should happen if the transfer fails isn't entirely clear, but a
reasonably conservative approach is to pretend that no media is
present.
A similar problem exists in a usb_stor_dbg() call in
alauda_get_media_status(). In this case, when an error occurs the
call is redundant, because usb_stor_ctrl_transfer() already will print
a debugging message.
Finally, unrelated to the uninitialized memory access, is the fact
that alauda_check_media() performs DMA to a buffer on the stack.
Fortunately usb-storage provides a general purpose DMA-able buffer for
uses like this. We'll use it instead. |