In the Linux kernel, the following vulnerability has been resolved:
tcp: fix skb_copy_ubufs() vs BIG TCP
David Ahern reported crashes in skb_copy_ubufs() caused by TCP tx zerocopy
using hugepages, and skb length bigger than ~68 KB.
skb_copy_ubufs() assumed it could copy all payload using up to
MAX_SKB_FRAGS order-0 pages.
This assumption broke when BIG TCP was able to put up to 512 KB per skb.
We did not hit this bug at Google because we use CONFIG_MAX_SKB_FRAGS=45
and limit gso_max_size to 180000.
A solution is to use higher order pages if needed.
v2: add missing __GFP_COMP, or we leak memory.
In the Linux kernel, the following vulnerability has been resolved:
drivers/perf: hisi: Don't migrate perf to the CPU going to teardown
The driver needs to migrate the perf context if the current using CPU going
to teardown. By the time calling the cpuhp::teardown() callback the
cpu_online_mask() hasn't updated yet and still includes the CPU going to
teardown. In current driver's implementation we may migrate the context
to the teardown CPU and leads to the below calltrace:
...
[ 368.104662][ T932] task:cpuhp/0 state:D stack: 0 pid: 15 ppid: 2 flags:0x00000008
[ 368.113699][ T932] Call trace:
[ 368.116834][ T932] __switch_to+0x7c/0xbc
[ 368.120924][ T932] __schedule+0x338/0x6f0
[ 368.125098][ T932] schedule+0x50/0xe0
[ 368.128926][ T932] schedule_preempt_disabled+0x18/0x24
[ 368.134229][ T932] __mutex_lock.constprop.0+0x1d4/0x5dc
[ 368.139617][ T932] __mutex_lock_slowpath+0x1c/0x30
[ 368.144573][ T932] mutex_lock+0x50/0x60
[ 368.148579][ T932] perf_pmu_migrate_context+0x84/0x2b0
[ 368.153884][ T932] hisi_pcie_pmu_offline_cpu+0x90/0xe0 [hisi_pcie_pmu]
[ 368.160579][ T932] cpuhp_invoke_callback+0x2a0/0x650
[ 368.165707][ T932] cpuhp_thread_fun+0xe4/0x190
[ 368.170316][ T932] smpboot_thread_fn+0x15c/0x1a0
[ 368.175099][ T932] kthread+0x108/0x13c
[ 368.179012][ T932] ret_from_fork+0x10/0x18
...
Use function cpumask_any_but() to find one correct active cpu to fixes
this issue.
In the Linux kernel, the following vulnerability has been resolved:
ice: Don't tx before switchdev is fully configured
There is possibility that ice_eswitch_port_start_xmit might be
called while some resources are still not allocated which might
cause NULL pointer dereference. Fix this by checking if switchdev
configuration was finished.
In the Linux kernel, the following vulnerability has been resolved:
spi: bcm-qspi: return error if neither hif_mspi nor mspi is available
If neither a "hif_mspi" nor "mspi" resource is present, the driver will
just early exit in probe but still return success. Apart from not doing
anything meaningful, this would then also lead to a null pointer access
on removal, as platform_get_drvdata() would return NULL, which it would
then try to dereference when trying to unregister the spi master.
Fix this by unconditionally calling devm_ioremap_resource(), as it can
handle a NULL res and will then return a viable ERR_PTR() if we get one.
The "return 0;" was previously a "goto qspi_resource_err;" where then
ret was returned, but since ret was still initialized to 0 at this place
this was a valid conversion in 63c5395bb7a9 ("spi: bcm-qspi: Fix
use-after-free on unbind"). The issue was not introduced by this commit,
only made more obvious.
In the Linux kernel, the following vulnerability has been resolved:
bpf, cpumap: Handle skb as well when clean up ptr_ring
The following warning was reported when running xdp_redirect_cpu with
both skb-mode and stress-mode enabled:
------------[ cut here ]------------
Incorrect XDP memory type (-2128176192) usage
WARNING: CPU: 7 PID: 1442 at net/core/xdp.c:405
Modules linked in:
CPU: 7 PID: 1442 Comm: kworker/7:0 Tainted: G 6.5.0-rc2+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Workqueue: events __cpu_map_entry_free
RIP: 0010:__xdp_return+0x1e4/0x4a0
......
Call Trace:
<TASK>
? show_regs+0x65/0x70
? __warn+0xa5/0x240
? __xdp_return+0x1e4/0x4a0
......
xdp_return_frame+0x4d/0x150
__cpu_map_entry_free+0xf9/0x230
process_one_work+0x6b0/0xb80
worker_thread+0x96/0x720
kthread+0x1a5/0x1f0
ret_from_fork+0x3a/0x70
ret_from_fork_asm+0x1b/0x30
</TASK>
The reason for the warning is twofold. One is due to the kthread
cpu_map_kthread_run() is stopped prematurely. Another one is
__cpu_map_ring_cleanup() doesn't handle skb mode and treats skbs in
ptr_ring as XDP frames.
Prematurely-stopped kthread will be fixed by the preceding patch and
ptr_ring will be empty when __cpu_map_ring_cleanup() is called. But
as the comments in __cpu_map_ring_cleanup() said, handling and freeing
skbs in ptr_ring as well to "catch any broken behaviour gracefully".
In the Linux kernel, the following vulnerability has been resolved:
bnxt: avoid overflow in bnxt_get_nvram_directory()
The value of an arithmetic expression is subject
of possible overflow due to a failure to cast operands to a larger data
type before performing arithmetic. Used macro for multiplication instead
operator for avoiding overflow.
Found by Security Code and Linux Verification
Center (linuxtesting.org) with SVACE.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix memory leaks in ext4_fname_{setup_filename,prepare_lookup}
If the filename casefolding fails, we'll be leaking memory from the
fscrypt_name struct, namely from the 'crypto_buf.name' member.
Make sure we free it in the error path on both ext4_fname_setup_filename()
and ext4_fname_prepare_lookup() functions.