| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
raid1: fix use-after-free for original bio in raid1_write_request()
r1_bio->bios[] is used to record new bios that will be issued to
underlying disks, however, in raid1_write_request(), r1_bio->bios[]
will set to the original bio temporarily. Meanwhile, if blocked rdev
is set, free_r1bio() will be called causing that all r1_bio->bios[]
to be freed:
raid1_write_request()
r1_bio = alloc_r1bio(mddev, bio); -> r1_bio->bios[] is NULL
for (i = 0; i < disks; i++) -> for each rdev in conf
// first rdev is normal
r1_bio->bios[0] = bio; -> set to original bio
// second rdev is blocked
if (test_bit(Blocked, &rdev->flags))
break
if (blocked_rdev)
free_r1bio()
put_all_bios()
bio_put(r1_bio->bios[0]) -> original bio is freed
Test scripts:
mdadm -CR /dev/md0 -l1 -n4 /dev/sd[abcd] --assume-clean
fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 \
-iodepth=128 -name=test -direct=1
echo blocked > /sys/block/md0/md/rd2/state
Test result:
BUG bio-264 (Not tainted): Object already free
-----------------------------------------------------------------------------
Allocated in mempool_alloc_slab+0x24/0x50 age=1 cpu=1 pid=869
kmem_cache_alloc+0x324/0x480
mempool_alloc_slab+0x24/0x50
mempool_alloc+0x6e/0x220
bio_alloc_bioset+0x1af/0x4d0
blkdev_direct_IO+0x164/0x8a0
blkdev_write_iter+0x309/0x440
aio_write+0x139/0x2f0
io_submit_one+0x5ca/0xb70
__do_sys_io_submit+0x86/0x270
__x64_sys_io_submit+0x22/0x30
do_syscall_64+0xb1/0x210
entry_SYSCALL_64_after_hwframe+0x6c/0x74
Freed in mempool_free_slab+0x1f/0x30 age=1 cpu=1 pid=869
kmem_cache_free+0x28c/0x550
mempool_free_slab+0x1f/0x30
mempool_free+0x40/0x100
bio_free+0x59/0x80
bio_put+0xf0/0x220
free_r1bio+0x74/0xb0
raid1_make_request+0xadf/0x1150
md_handle_request+0xc7/0x3b0
md_submit_bio+0x76/0x130
__submit_bio+0xd8/0x1d0
submit_bio_noacct_nocheck+0x1eb/0x5c0
submit_bio_noacct+0x169/0xd40
submit_bio+0xee/0x1d0
blkdev_direct_IO+0x322/0x8a0
blkdev_write_iter+0x309/0x440
aio_write+0x139/0x2f0
Since that bios for underlying disks are not allocated yet, fix this
problem by using mempool_free() directly to free the r1_bio. |
| In the Linux kernel, the following vulnerability has been resolved:
media: mediatek: vcodec: Fix oops when HEVC init fails
The stateless HEVC decoder saves the instance pointer in the context
regardless if the initialization worked or not. This caused a use after
free, when the pointer is freed in case of a failure in the deinit
function.
Only store the instance pointer when the initialization was successful,
to solve this issue.
Hardware name: Acer Tomato (rev3 - 4) board (DT)
pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
lr : vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
sp : ffff80008750bc20
x29: ffff80008750bc20 x28: ffff1299f6d70000 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
x23: ffff80008750bc98 x22: 000000000000a003 x21: ffffd45c4cfae000
x20: 0000000000000010 x19: ffff1299fd668310 x18: 000000000000001a
x17: 000000040044ffff x16: ffffd45cb15dc648 x15: 0000000000000000
x14: ffff1299c08da1c0 x13: ffffd45cb1f87a10 x12: ffffd45cb2f5fe80
x11: 0000000000000001 x10: 0000000000001b30 x9 : ffffd45c4d12b488
x8 : 1fffe25339380d81 x7 : 0000000000000001 x6 : ffff1299c9c06c00
x5 : 0000000000000132 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000010 x1 : ffff80008750bc98 x0 : 0000000000000000
Call trace:
vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
vpu_dec_deinit+0x1c/0x30 [mtk_vcodec_dec]
vdec_hevc_slice_deinit+0x30/0x98 [mtk_vcodec_dec]
vdec_if_deinit+0x38/0x68 [mtk_vcodec_dec]
mtk_vcodec_dec_release+0x20/0x40 [mtk_vcodec_dec]
fops_vcodec_release+0x64/0x118 [mtk_vcodec_dec]
v4l2_release+0x7c/0x100
__fput+0x80/0x2d8
__fput_sync+0x58/0x70
__arm64_sys_close+0x40/0x90
invoke_syscall+0x50/0x128
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x38/0xd8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x1a8/0x1b0
Code: d503201f f9401660 b900127f b900227f (f9400400) |
| In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrum_acl_tcam: Fix possible use-after-free during activity update
The rule activity update delayed work periodically traverses the list of
configured rules and queries their activity from the device.
As part of this task it accesses the entry pointed by 'ventry->entry',
but this entry can be changed concurrently by the rehash delayed work,
leading to a use-after-free [1].
Fix by closing the race and perform the activity query under the
'vregion->lock' mutex.
[1]
BUG: KASAN: slab-use-after-free in mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
Read of size 8 at addr ffff8881054ed808 by task kworker/0:18/181
CPU: 0 PID: 181 Comm: kworker/0:18 Not tainted 6.9.0-rc2-custom-00781-gd5ab772d32f7 #2
Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
Workqueue: mlxsw_core mlxsw_sp_acl_rule_activity_update_work
Call Trace:
<TASK>
dump_stack_lvl+0xc6/0x120
print_report+0xce/0x670
kasan_report+0xd7/0x110
mlxsw_sp_acl_tcam_flower_rule_activity_get+0x121/0x140
mlxsw_sp_acl_rule_activity_update_work+0x219/0x400
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 1039:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
__kmalloc+0x19c/0x360
mlxsw_sp_acl_tcam_entry_create+0x7b/0x1f0
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x30d/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30
Freed by task 1039:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
poison_slab_object+0x102/0x170
__kasan_slab_free+0x14/0x30
kfree+0xc1/0x290
mlxsw_sp_acl_tcam_vchunk_migrate_all+0x3d7/0xb50
mlxsw_sp_acl_tcam_vregion_rehash_work+0x157/0x1300
process_one_work+0x8eb/0x19b0
worker_thread+0x6c9/0xf70
kthread+0x2c9/0x3b0
ret_from_fork+0x4d/0x80
ret_from_fork_asm+0x1a/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: sun8i-ce - Fix use after free in unprepare
sun8i_ce_cipher_unprepare should be called before
crypto_finalize_skcipher_request, because client callbacks may
immediately free memory, that isn't needed anymore. But it will be
used by unprepare after free. Before removing prepare/unprepare
callbacks it was handled by crypto engine in crypto_finalize_request.
Usually that results in a pointer dereference problem during a in
crypto selftest.
Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000030
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
CM = 0, WnR = 0, TnD = 0, TagAccess = 0
GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=000000004716d000
[0000000000000030] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000004 [#1] SMP
This problem is detected by KASAN as well.
==================================================================
BUG: KASAN: slab-use-after-free in sun8i_ce_cipher_do_one+0x6e8/0xf80 [sun8i_ce]
Read of size 8 at addr ffff00000dcdc040 by task 1c15000.crypto-/373
Hardware name: Pine64 PinePhone (1.2) (DT)
Call trace:
dump_backtrace+0x9c/0x128
show_stack+0x20/0x38
dump_stack_lvl+0x48/0x60
print_report+0xf8/0x5d8
kasan_report+0x90/0xd0
__asan_load8+0x9c/0xc0
sun8i_ce_cipher_do_one+0x6e8/0xf80 [sun8i_ce]
crypto_pump_work+0x354/0x620 [crypto_engine]
kthread_worker_fn+0x244/0x498
kthread+0x168/0x178
ret_from_fork+0x10/0x20
Allocated by task 379:
kasan_save_stack+0x3c/0x68
kasan_set_track+0x2c/0x40
kasan_save_alloc_info+0x24/0x38
__kasan_kmalloc+0xd4/0xd8
__kmalloc+0x74/0x1d0
alg_test_skcipher+0x90/0x1f0
alg_test+0x24c/0x830
cryptomgr_test+0x38/0x60
kthread+0x168/0x178
ret_from_fork+0x10/0x20
Freed by task 379:
kasan_save_stack+0x3c/0x68
kasan_set_track+0x2c/0x40
kasan_save_free_info+0x38/0x60
__kasan_slab_free+0x100/0x170
slab_free_freelist_hook+0xd4/0x1e8
__kmem_cache_free+0x15c/0x290
kfree+0x74/0x100
kfree_sensitive+0x80/0xb0
alg_test_skcipher+0x12c/0x1f0
alg_test+0x24c/0x830
cryptomgr_test+0x38/0x60
kthread+0x168/0x178
ret_from_fork+0x10/0x20
The buggy address belongs to the object at ffff00000dcdc000
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 64 bytes inside of
freed 256-byte region [ffff00000dcdc000, ffff00000dcdc100) |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: mt7925e: fix use-after-free in free_irq()
From commit a304e1b82808 ("[PATCH] Debug shared irqs"), there is a test
to make sure the shared irq handler should be able to handle the unexpected
event after deregistration. For this case, let's apply MT76_REMOVED flag to
indicate the device was removed and do not run into the resource access
anymore. |
| In the Linux kernel, the following vulnerability has been resolved:
media: edia: dvbdev: fix a use-after-free
In dvb_register_device, *pdvbdev is set equal to dvbdev, which is freed
in several error-handling paths. However, *pdvbdev is not set to NULL
after dvbdev's deallocation, causing use-after-frees in many places,
for example, in the following call chain:
budget_register
|-> dvb_dmxdev_init
|-> dvb_register_device
|-> dvb_dmxdev_release
|-> dvb_unregister_device
|-> dvb_remove_device
|-> dvb_device_put
|-> kref_put
When calling dvb_unregister_device, dmxdev->dvbdev (i.e. *pdvbdev in
dvb_register_device) could point to memory that had been freed in
dvb_register_device. Thereafter, this pointer is transferred to
kref_put and triggering a use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
spi: lpspi: Avoid potential use-after-free in probe()
fsl_lpspi_probe() is allocating/disposing memory manually with
spi_alloc_host()/spi_alloc_target(), but uses
devm_spi_register_controller(). In case of error after the latter call the
memory will be explicitly freed in the probe function by
spi_controller_put() call, but used afterwards by "devm" management outside
probe() (spi_unregister_controller() <- devm_spi_unregister() below).
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000070
...
Call trace:
kernfs_find_ns
kernfs_find_and_get_ns
sysfs_remove_group
sysfs_remove_groups
device_remove_attrs
device_del
spi_unregister_controller
devm_spi_unregister
release_nodes
devres_release_all
really_probe
driver_probe_device
__device_attach_driver
bus_for_each_drv
__device_attach
device_initial_probe
bus_probe_device
deferred_probe_work_func
process_one_work
worker_thread
kthread
ret_from_fork |
| In the Linux kernel, the following vulnerability has been resolved:
rds: tcp: Fix use-after-free of net in reqsk_timer_handler().
syzkaller reported a warning of netns tracker [0] followed by KASAN
splat [1] and another ref tracker warning [1].
syzkaller could not find a repro, but in the log, the only suspicious
sequence was as follows:
18:26:22 executing program 1:
r0 = socket$inet6_mptcp(0xa, 0x1, 0x106)
...
connect$inet6(r0, &(0x7f0000000080)={0xa, 0x4001, 0x0, @loopback}, 0x1c) (async)
The notable thing here is 0x4001 in connect(), which is RDS_TCP_PORT.
So, the scenario would be:
1. unshare(CLONE_NEWNET) creates a per netns tcp listener in
rds_tcp_listen_init().
2. syz-executor connect()s to it and creates a reqsk.
3. syz-executor exit()s immediately.
4. netns is dismantled. [0]
5. reqsk timer is fired, and UAF happens while freeing reqsk. [1]
6. listener is freed after RCU grace period. [2]
Basically, reqsk assumes that the listener guarantees netns safety
until all reqsk timers are expired by holding the listener's refcount.
However, this was not the case for kernel sockets.
Commit 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in
inet_twsk_purge()") fixed this issue only for per-netns ehash.
Let's apply the same fix for the global ehash.
[0]:
ref_tracker: net notrefcnt@0000000065449cc3 has 1/1 users at
sk_alloc (./include/net/net_namespace.h:337 net/core/sock.c:2146)
inet6_create (net/ipv6/af_inet6.c:192 net/ipv6/af_inet6.c:119)
__sock_create (net/socket.c:1572)
rds_tcp_listen_init (net/rds/tcp_listen.c:279)
rds_tcp_init_net (net/rds/tcp.c:577)
ops_init (net/core/net_namespace.c:137)
setup_net (net/core/net_namespace.c:340)
copy_net_ns (net/core/net_namespace.c:497)
create_new_namespaces (kernel/nsproxy.c:110)
unshare_nsproxy_namespaces (kernel/nsproxy.c:228 (discriminator 4))
ksys_unshare (kernel/fork.c:3429)
__x64_sys_unshare (kernel/fork.c:3496)
do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
...
WARNING: CPU: 0 PID: 27 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179)
[1]:
BUG: KASAN: slab-use-after-free in inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
Read of size 8 at addr ffff88801b370400 by task swapper/0/0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)
kasan_report (mm/kasan/report.c:603)
inet_csk_reqsk_queue_drop (./include/net/inet_hashtables.h:180 net/ipv4/inet_connection_sock.c:952 net/ipv4/inet_connection_sock.c:966)
reqsk_timer_handler (net/ipv4/inet_connection_sock.c:979 net/ipv4/inet_connection_sock.c:1092)
call_timer_fn (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/timer.h:127 kernel/time/timer.c:1701)
__run_timers.part.0 (kernel/time/timer.c:1752 kernel/time/timer.c:2038)
run_timer_softirq (kernel/time/timer.c:2053)
__do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:554)
irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:644)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1076 (discriminator 14))
</IRQ>
Allocated by task 258 on cpu 0 at 83.612050s:
kasan_save_stack (mm/kasan/common.c:48)
kasan_save_track (mm/kasan/common.c:68)
__kasan_slab_alloc (mm/kasan/common.c:343)
kmem_cache_alloc (mm/slub.c:3813 mm/slub.c:3860 mm/slub.c:3867)
copy_net_ns (./include/linux/slab.h:701 net/core/net_namespace.c:421 net/core/net_namespace.c:480)
create_new_namespaces (kernel/nsproxy.c:110)
unshare_nsproxy_name
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
spi: cadence-qspi: remove system-wide suspend helper calls from runtime PM hooks
The ->runtime_suspend() and ->runtime_resume() callbacks are not
expected to call spi_controller_suspend() and spi_controller_resume().
Remove calls to those in the cadence-qspi driver.
Those helpers have two roles currently:
- They stop/start the queue, including dealing with the kworker.
- They toggle the SPI controller SPI_CONTROLLER_SUSPENDED flag. It
requires acquiring ctlr->bus_lock_mutex.
Step one is irrelevant because cadence-qspi is not queued. Step two
however has two implications:
- A deadlock occurs, because ->runtime_resume() is called in a context
where the lock is already taken (in the ->exec_op() callback, where
the usage count is incremented).
- It would disallow all operations once the device is auto-suspended.
Here is a brief call tree highlighting the mutex deadlock:
spi_mem_exec_op()
...
spi_mem_access_start()
mutex_lock(&ctlr->bus_lock_mutex)
cqspi_exec_mem_op()
pm_runtime_resume_and_get()
cqspi_resume()
spi_controller_resume()
mutex_lock(&ctlr->bus_lock_mutex)
...
spi_mem_access_end()
mutex_unlock(&ctlr->bus_lock_mutex)
... |
| In the Linux kernel, the following vulnerability has been resolved:
gtp: fix use-after-free and null-ptr-deref in gtp_newlink()
The gtp_link_ops operations structure for the subsystem must be
registered after registering the gtp_net_ops pernet operations structure.
Syzkaller hit 'general protection fault in gtp_genl_dump_pdp' bug:
[ 1010.702740] gtp: GTP module unloaded
[ 1010.715877] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
[ 1010.715888] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 1010.715895] CPU: 1 PID: 128616 Comm: a.out Not tainted 6.8.0-rc6-std-def-alt1 #1
[ 1010.715899] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-alt1 04/01/2014
[ 1010.715908] RIP: 0010:gtp_newlink+0x4d7/0x9c0 [gtp]
[ 1010.715915] Code: 80 3c 02 00 0f 85 41 04 00 00 48 8b bb d8 05 00 00 e8 ed f6 ff ff 48 89 c2 48 89 c5 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4f 04 00 00 4c 89 e2 4c 8b 6d 00 48 b8 00 00 00
[ 1010.715920] RSP: 0018:ffff888020fbf180 EFLAGS: 00010203
[ 1010.715929] RAX: dffffc0000000000 RBX: ffff88800399c000 RCX: 0000000000000000
[ 1010.715933] RDX: 0000000000000001 RSI: ffffffff84805280 RDI: 0000000000000282
[ 1010.715938] RBP: 000000000000000d R08: 0000000000000001 R09: 0000000000000000
[ 1010.715942] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88800399cc80
[ 1010.715947] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000400
[ 1010.715953] FS: 00007fd1509ab5c0(0000) GS:ffff88805b300000(0000) knlGS:0000000000000000
[ 1010.715958] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1010.715962] CR2: 0000000000000000 CR3: 000000001c07a000 CR4: 0000000000750ee0
[ 1010.715968] PKRU: 55555554
[ 1010.715972] Call Trace:
[ 1010.715985] ? __die_body.cold+0x1a/0x1f
[ 1010.715995] ? die_addr+0x43/0x70
[ 1010.716002] ? exc_general_protection+0x199/0x2f0
[ 1010.716016] ? asm_exc_general_protection+0x1e/0x30
[ 1010.716026] ? gtp_newlink+0x4d7/0x9c0 [gtp]
[ 1010.716034] ? gtp_net_exit+0x150/0x150 [gtp]
[ 1010.716042] __rtnl_newlink+0x1063/0x1700
[ 1010.716051] ? rtnl_setlink+0x3c0/0x3c0
[ 1010.716063] ? is_bpf_text_address+0xc0/0x1f0
[ 1010.716070] ? kernel_text_address.part.0+0xbb/0xd0
[ 1010.716076] ? __kernel_text_address+0x56/0xa0
[ 1010.716084] ? unwind_get_return_address+0x5a/0xa0
[ 1010.716091] ? create_prof_cpu_mask+0x30/0x30
[ 1010.716098] ? arch_stack_walk+0x9e/0xf0
[ 1010.716106] ? stack_trace_save+0x91/0xd0
[ 1010.716113] ? stack_trace_consume_entry+0x170/0x170
[ 1010.716121] ? __lock_acquire+0x15c5/0x5380
[ 1010.716139] ? mark_held_locks+0x9e/0xe0
[ 1010.716148] ? kmem_cache_alloc_trace+0x35f/0x3c0
[ 1010.716155] ? __rtnl_newlink+0x1700/0x1700
[ 1010.716160] rtnl_newlink+0x69/0xa0
[ 1010.716166] rtnetlink_rcv_msg+0x43b/0xc50
[ 1010.716172] ? rtnl_fdb_dump+0x9f0/0x9f0
[ 1010.716179] ? lock_acquire+0x1fe/0x560
[ 1010.716188] ? netlink_deliver_tap+0x12f/0xd50
[ 1010.716196] netlink_rcv_skb+0x14d/0x440
[ 1010.716202] ? rtnl_fdb_dump+0x9f0/0x9f0
[ 1010.716208] ? netlink_ack+0xab0/0xab0
[ 1010.716213] ? netlink_deliver_tap+0x202/0xd50
[ 1010.716220] ? netlink_deliver_tap+0x218/0xd50
[ 1010.716226] ? __virt_addr_valid+0x30b/0x590
[ 1010.716233] netlink_unicast+0x54b/0x800
[ 1010.716240] ? netlink_attachskb+0x870/0x870
[ 1010.716248] ? __check_object_size+0x2de/0x3b0
[ 1010.716254] netlink_sendmsg+0x938/0xe40
[ 1010.716261] ? netlink_unicast+0x800/0x800
[ 1010.716269] ? __import_iovec+0x292/0x510
[ 1010.716276] ? netlink_unicast+0x800/0x800
[ 1010.716284] __sock_sendmsg+0x159/0x190
[ 1010.716290] ____sys_sendmsg+0x712/0x880
[ 1010.716297] ? sock_write_iter+0x3d0/0x3d0
[ 1010.716304] ? __ia32_sys_recvmmsg+0x270/0x270
[ 1010.716309] ? lock_acquire+0x1fe/0x560
[ 1010.716315] ? drain_array_locked+0x90/0x90
[ 1010.716324] ___sys_sendmsg+0xf8/0x170
[ 1010.716331] ? sendmsg_copy_msghdr+0x170/0x170
[ 1010.716337] ? lockdep_init_map
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
gtp: fix use-after-free and null-ptr-deref in gtp_genl_dump_pdp()
The gtp_net_ops pernet operations structure for the subsystem must be
registered before registering the generic netlink family.
Syzkaller hit 'general protection fault in gtp_genl_dump_pdp' bug:
general protection fault, probably for non-canonical address
0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 5826 Comm: gtp Not tainted 6.8.0-rc3-std-def-alt1 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-alt1 04/01/2014
RIP: 0010:gtp_genl_dump_pdp+0x1be/0x800 [gtp]
Code: c6 89 c6 e8 64 e9 86 df 58 45 85 f6 0f 85 4e 04 00 00 e8 c5 ee 86
df 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
3c 02 00 0f 85 de 05 00 00 48 8b 44 24 18 4c 8b 30 4c 39 f0 74
RSP: 0018:ffff888014107220 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88800fcda588 R14: 0000000000000001 R15: 0000000000000000
FS: 00007f1be4eb05c0(0000) GS:ffff88806ce80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1be4e766cf CR3: 000000000c33e000 CR4: 0000000000750ef0
PKRU: 55555554
Call Trace:
<TASK>
? show_regs+0x90/0xa0
? die_addr+0x50/0xd0
? exc_general_protection+0x148/0x220
? asm_exc_general_protection+0x22/0x30
? gtp_genl_dump_pdp+0x1be/0x800 [gtp]
? __alloc_skb+0x1dd/0x350
? __pfx___alloc_skb+0x10/0x10
genl_dumpit+0x11d/0x230
netlink_dump+0x5b9/0xce0
? lockdep_hardirqs_on_prepare+0x253/0x430
? __pfx_netlink_dump+0x10/0x10
? kasan_save_track+0x10/0x40
? __kasan_kmalloc+0x9b/0xa0
? genl_start+0x675/0x970
__netlink_dump_start+0x6fc/0x9f0
genl_family_rcv_msg_dumpit+0x1bb/0x2d0
? __pfx_genl_family_rcv_msg_dumpit+0x10/0x10
? genl_op_from_small+0x2a/0x440
? cap_capable+0x1d0/0x240
? __pfx_genl_start+0x10/0x10
? __pfx_genl_dumpit+0x10/0x10
? __pfx_genl_done+0x10/0x10
? security_capable+0x9d/0xe0 |
| In the Linux kernel, the following vulnerability has been resolved:
usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable()
...
cdns3_gadget_ep_free_request(&priv_ep->endpoint, &priv_req->request);
list_del_init(&priv_req->list);
...
'priv_req' actually free at cdns3_gadget_ep_free_request(). But
list_del_init() use priv_req->list after it.
[ 1542.642868][ T534] BUG: KFENCE: use-after-free read in __list_del_entry_valid+0x10/0xd4
[ 1542.642868][ T534]
[ 1542.653162][ T534] Use-after-free read at 0x000000009ed0ba99 (in kfence-#3):
[ 1542.660311][ T534] __list_del_entry_valid+0x10/0xd4
[ 1542.665375][ T534] cdns3_gadget_ep_disable+0x1f8/0x388 [cdns3]
[ 1542.671571][ T534] usb_ep_disable+0x44/0xe4
[ 1542.675948][ T534] ffs_func_eps_disable+0x64/0xc8
[ 1542.680839][ T534] ffs_func_set_alt+0x74/0x368
[ 1542.685478][ T534] ffs_func_disable+0x18/0x28
Move list_del_init() before cdns3_gadget_ep_free_request() to resolve this
problem. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: sr: fix possible use-after-free and null-ptr-deref
The pernet operations structure for the subsystem must be registered
before registering the generic netlink family. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5: DPLL, Fix possible use after free after delayed work timer triggers
I managed to hit following use after free warning recently:
[ 2169.711665] ==================================================================
[ 2169.714009] BUG: KASAN: slab-use-after-free in __run_timers.part.0+0x179/0x4c0
[ 2169.716293] Write of size 8 at addr ffff88812b326a70 by task swapper/4/0
[ 2169.719022] CPU: 4 PID: 0 Comm: swapper/4 Not tainted 6.8.0-rc2jiri+ #2
[ 2169.720974] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 2169.722457] Call Trace:
[ 2169.722756] <IRQ>
[ 2169.723024] dump_stack_lvl+0x58/0xb0
[ 2169.723417] print_report+0xc5/0x630
[ 2169.723807] ? __virt_addr_valid+0x126/0x2b0
[ 2169.724268] kasan_report+0xbe/0xf0
[ 2169.724667] ? __run_timers.part.0+0x179/0x4c0
[ 2169.725116] ? __run_timers.part.0+0x179/0x4c0
[ 2169.725570] __run_timers.part.0+0x179/0x4c0
[ 2169.726003] ? call_timer_fn+0x320/0x320
[ 2169.726404] ? lock_downgrade+0x3a0/0x3a0
[ 2169.726820] ? kvm_clock_get_cycles+0x14/0x20
[ 2169.727257] ? ktime_get+0x92/0x150
[ 2169.727630] ? lapic_next_deadline+0x35/0x60
[ 2169.728069] run_timer_softirq+0x40/0x80
[ 2169.728475] __do_softirq+0x1a1/0x509
[ 2169.728866] irq_exit_rcu+0x95/0xc0
[ 2169.729241] sysvec_apic_timer_interrupt+0x6b/0x80
[ 2169.729718] </IRQ>
[ 2169.729993] <TASK>
[ 2169.730259] asm_sysvec_apic_timer_interrupt+0x16/0x20
[ 2169.730755] RIP: 0010:default_idle+0x13/0x20
[ 2169.731190] Code: c0 08 00 00 00 4d 29 c8 4c 01 c7 4c 29 c2 e9 72 ff ff ff cc cc cc cc 8b 05 9a 7f 1f 02 85 c0 7e 07 0f 00 2d cf 69 43 00 fb f4 <fa> c3 66 66 2e 0f 1f 84 00 00 00 00 00 65 48 8b 04 25 c0 93 04 00
[ 2169.732759] RSP: 0018:ffff888100dbfe10 EFLAGS: 00000242
[ 2169.733264] RAX: 0000000000000001 RBX: ffff888100d9c200 RCX: ffffffff8241bd62
[ 2169.733925] RDX: ffffed109a848b15 RSI: 0000000000000004 RDI: ffffffff8127ac55
[ 2169.734566] RBP: 0000000000000004 R08: 0000000000000000 R09: ffffed109a848b14
[ 2169.735200] R10: ffff8884d42458a3 R11: 000000000000ba7e R12: ffffffff83d7d3a0
[ 2169.735835] R13: 1ffff110201b7fc6 R14: 0000000000000000 R15: ffff888100d9c200
[ 2169.736478] ? ct_kernel_exit.constprop.0+0xa2/0xc0
[ 2169.736954] ? do_idle+0x285/0x290
[ 2169.737323] default_idle_call+0x63/0x90
[ 2169.737730] do_idle+0x285/0x290
[ 2169.738089] ? arch_cpu_idle_exit+0x30/0x30
[ 2169.738511] ? mark_held_locks+0x1a/0x80
[ 2169.738917] ? lockdep_hardirqs_on_prepare+0x12e/0x200
[ 2169.739417] cpu_startup_entry+0x30/0x40
[ 2169.739825] start_secondary+0x19a/0x1c0
[ 2169.740229] ? set_cpu_sibling_map+0xbd0/0xbd0
[ 2169.740673] secondary_startup_64_no_verify+0x15d/0x16b
[ 2169.741179] </TASK>
[ 2169.741686] Allocated by task 1098:
[ 2169.742058] kasan_save_stack+0x1c/0x40
[ 2169.742456] kasan_save_track+0x10/0x30
[ 2169.742852] __kasan_kmalloc+0x83/0x90
[ 2169.743246] mlx5_dpll_probe+0xf5/0x3c0 [mlx5_dpll]
[ 2169.743730] auxiliary_bus_probe+0x62/0xb0
[ 2169.744148] really_probe+0x127/0x590
[ 2169.744534] __driver_probe_device+0xd2/0x200
[ 2169.744973] device_driver_attach+0x6b/0xf0
[ 2169.745402] bind_store+0x90/0xe0
[ 2169.745761] kernfs_fop_write_iter+0x1df/0x2a0
[ 2169.746210] vfs_write+0x41f/0x790
[ 2169.746579] ksys_write+0xc7/0x160
[ 2169.746947] do_syscall_64+0x6f/0x140
[ 2169.747333] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[ 2169.748049] Freed by task 1220:
[ 2169.748393] kasan_save_stack+0x1c/0x40
[ 2169.748789] kasan_save_track+0x10/0x30
[ 2169.749188] kasan_save_free_info+0x3b/0x50
[ 2169.749621] poison_slab_object+0x106/0x180
[ 2169.750044] __kasan_slab_free+0x14/0x50
[ 2169.750451] kfree+0x118/0x330
[ 2169.750792] mlx5_dpll_remove+0xf5/0x110 [mlx5_dpll]
[ 2169.751271] auxiliary_bus_remove+0x2e/0x40
[ 2169.751694] device_release_driver_internal+0x24b/0x2e0
[ 2169.752191] unbind_store+0xa6/0xb0
[ 2169.752563] kernfs_fo
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: atlantic: Fix DMA mapping for PTP hwts ring
Function aq_ring_hwts_rx_alloc() maps extra AQ_CFG_RXDS_DEF bytes
for PTP HWTS ring but then generic aq_ring_free() does not take this
into account.
Create and use a specific function to free HWTS ring to fix this
issue.
Trace:
[ 215.351607] ------------[ cut here ]------------
[ 215.351612] DMA-API: atlantic 0000:4b:00.0: device driver frees DMA memory with different size [device address=0x00000000fbdd0000] [map size=34816 bytes] [unmap size=32768 bytes]
[ 215.351635] WARNING: CPU: 33 PID: 10759 at kernel/dma/debug.c:988 check_unmap+0xa6f/0x2360
...
[ 215.581176] Call Trace:
[ 215.583632] <TASK>
[ 215.585745] ? show_trace_log_lvl+0x1c4/0x2df
[ 215.590114] ? show_trace_log_lvl+0x1c4/0x2df
[ 215.594497] ? debug_dma_free_coherent+0x196/0x210
[ 215.599305] ? check_unmap+0xa6f/0x2360
[ 215.603147] ? __warn+0xca/0x1d0
[ 215.606391] ? check_unmap+0xa6f/0x2360
[ 215.610237] ? report_bug+0x1ef/0x370
[ 215.613921] ? handle_bug+0x3c/0x70
[ 215.617423] ? exc_invalid_op+0x14/0x50
[ 215.621269] ? asm_exc_invalid_op+0x16/0x20
[ 215.625480] ? check_unmap+0xa6f/0x2360
[ 215.629331] ? mark_lock.part.0+0xca/0xa40
[ 215.633445] debug_dma_free_coherent+0x196/0x210
[ 215.638079] ? __pfx_debug_dma_free_coherent+0x10/0x10
[ 215.643242] ? slab_free_freelist_hook+0x11d/0x1d0
[ 215.648060] dma_free_attrs+0x6d/0x130
[ 215.651834] aq_ring_free+0x193/0x290 [atlantic]
[ 215.656487] aq_ptp_ring_free+0x67/0x110 [atlantic]
...
[ 216.127540] ---[ end trace 6467e5964dd2640b ]---
[ 216.132160] DMA-API: Mapped at:
[ 216.132162] debug_dma_alloc_coherent+0x66/0x2f0
[ 216.132165] dma_alloc_attrs+0xf5/0x1b0
[ 216.132168] aq_ring_hwts_rx_alloc+0x150/0x1f0 [atlantic]
[ 216.132193] aq_ptp_ring_alloc+0x1bb/0x540 [atlantic]
[ 216.132213] aq_nic_init+0x4a1/0x760 [atlantic] |
| In the Linux kernel, the following vulnerability has been resolved:
mm: cachestat: fix folio read-after-free in cache walk
In cachestat, we access the folio from the page cache's xarray to compute
its page offset, and check for its dirty and writeback flags. However, we
do not hold a reference to the folio before performing these actions,
which means the folio can concurrently be released and reused as another
folio/page/slab.
Get around this altogether by just using xarray's existing machinery for
the folio page offsets and dirty/writeback states.
This changes behavior for tmpfs files to now always report zeroes in their
dirty and writeback counters. This is okay as tmpfs doesn't follow
conventional writeback cache behavior: its pages get "cleaned" during
swapout, after which they're no longer resident etc. |
| In the Linux kernel, the following vulnerability has been resolved:
llc: call sock_orphan() at release time
syzbot reported an interesting trace [1] caused by a stale sk->sk_wq
pointer in a closed llc socket.
In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after
calling proto_ops::release()") Eric Biggers hinted that some protocols
are missing a sock_orphan(), we need to perform a full audit.
In net-next, I plan to clear sock->sk from sock_orphan() and
amend Eric patch to add a warning.
[1]
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline]
BUG: KASAN: slab-use-after-free in sock_def_write_space_wfree net/core/sock.c:3384 [inline]
BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468
Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27
CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc4/0x620 mm/kasan/report.c:488
kasan_report+0xda/0x110 mm/kasan/report.c:601
list_empty include/linux/list.h:373 [inline]
waitqueue_active include/linux/wait.h:127 [inline]
sock_def_write_space_wfree net/core/sock.c:3384 [inline]
sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468
skb_release_head_state+0xa3/0x2b0 net/core/skbuff.c:1080
skb_release_all net/core/skbuff.c:1092 [inline]
napi_consume_skb+0x119/0x2b0 net/core/skbuff.c:1404
e1000_unmap_and_free_tx_resource+0x144/0x200 drivers/net/ethernet/intel/e1000/e1000_main.c:1970
e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3860 [inline]
e1000_clean+0x4a1/0x26e0 drivers/net/ethernet/intel/e1000/e1000_main.c:3801
__napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6576
napi_poll net/core/dev.c:6645 [inline]
net_rx_action+0x956/0xe90 net/core/dev.c:6778
__do_softirq+0x21a/0x8de kernel/softirq.c:553
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x31/0x60 kernel/softirq.c:913
smpboot_thread_fn+0x660/0xa10 kernel/smpboot.c:164
kthread+0x2c6/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
Allocated by task 5167:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:314 [inline]
__kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3813 [inline]
slab_alloc_node mm/slub.c:3860 [inline]
kmem_cache_alloc_lru+0x142/0x6f0 mm/slub.c:3879
alloc_inode_sb include/linux/fs.h:3019 [inline]
sock_alloc_inode+0x25/0x1c0 net/socket.c:308
alloc_inode+0x5d/0x220 fs/inode.c:260
new_inode_pseudo+0x16/0x80 fs/inode.c:1005
sock_alloc+0x40/0x270 net/socket.c:634
__sock_create+0xbc/0x800 net/socket.c:1535
sock_create net/socket.c:1622 [inline]
__sys_socket_create net/socket.c:1659 [inline]
__sys_socket+0x14c/0x260 net/socket.c:1706
__do_sys_socket net/socket.c:1720 [inline]
__se_sys_socket net/socket.c:1718 [inline]
__x64_sys_socket+0x72/0xb0 net/socket.c:1718
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b
Freed by task 0:
kasan_save_stack+0x33/0x50 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640
poison_slab_object mm/kasan/common.c:241 [inline]
__kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inlin
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
riscv: Fix module loading free order
Reverse order of kfree calls to resolve use-after-free error. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned
[BUG]
There is a bug report that, on a ext4-converted btrfs, scrub leads to
various problems, including:
- "unable to find chunk map" errors
BTRFS info (device vdb): scrub: started on devid 1
BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 4096
BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 45056
This would lead to unrepariable errors.
- Use-after-free KASAN reports:
==================================================================
BUG: KASAN: slab-use-after-free in __blk_rq_map_sg+0x18f/0x7c0
Read of size 8 at addr ffff8881013c9040 by task btrfs/909
CPU: 0 PID: 909 Comm: btrfs Not tainted 6.7.0-x64v3-dbg #11 c50636e9419a8354555555245df535e380563b2b
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2023.11-2 12/24/2023
Call Trace:
<TASK>
dump_stack_lvl+0x43/0x60
print_report+0xcf/0x640
kasan_report+0xa6/0xd0
__blk_rq_map_sg+0x18f/0x7c0
virtblk_prep_rq.isra.0+0x215/0x6a0 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]
virtio_queue_rqs+0xc4/0x310 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]
blk_mq_flush_plug_list.part.0+0x780/0x860
__blk_flush_plug+0x1ba/0x220
blk_finish_plug+0x3b/0x60
submit_initial_group_read+0x10a/0x290 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
flush_scrub_stripes+0x38e/0x430 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_stripe+0x82a/0xae0 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_chunk+0x178/0x200 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_enumerate_chunks+0x4bc/0xa30 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
btrfs_scrub_dev+0x398/0x810 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
btrfs_ioctl+0x4b9/0x3020 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
__x64_sys_ioctl+0xbd/0x100
do_syscall_64+0x5d/0xe0
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f47e5e0952b
- Crash, mostly due to above use-after-free
[CAUSE]
The converted fs has the following data chunk layout:
item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 2214658048) itemoff 16025 itemsize 80
length 86016 owner 2 stripe_len 65536 type DATA|single
For above logical bytenr 2214744064, it's at the chunk end
(2214658048 + 86016 = 2214744064).
This means btrfs_submit_bio() would split the bio, and trigger endio
function for both of the two halves.
However scrub_submit_initial_read() would only expect the endio function
to be called once, not any more.
This means the first endio function would already free the bbio::bio,
leaving the bvec freed, thus the 2nd endio call would lead to
use-after-free.
[FIX]
- Make sure scrub_read_endio() only updates bits in its range
Since we may read less than 64K at the end of the chunk, we should not
touch the bits beyond chunk boundary.
- Make sure scrub_submit_initial_read() only to read the chunk range
This is done by calculating the real number of sectors we need to
read, and add sector-by-sector to the bio.
Thankfully the scrub read repair path won't need extra fixes:
- scrub_stripe_submit_repair_read()
With above fixes, we won't update error bit for range beyond chunk,
thus scrub_stripe_submit_repair_read() should never submit any read
beyond the chunk. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait
While performing fast composition switch, there is a possibility that the
process of ffs_ep0_write/ffs_ep0_read get into a race condition
due to ep0req being freed up from functionfs_unbind.
Consider the scenario that the ffs_ep0_write calls the ffs_ep0_queue_wait
by taking a lock &ffs->ev.waitq.lock. However, the functionfs_unbind isn't
bounded so it can go ahead and mark the ep0req to NULL, and since there
is no NULL check in ffs_ep0_queue_wait we will end up in use-after-free.
Fix this by making a serialized execution between the two functions using
a mutex_lock(ffs->mutex). |